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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: BlueScarecrow on December 27, 2009, 01:50:38 PM

Title: MC-9 / 8V71 Woes
Post by: BlueScarecrow on December 27, 2009, 01:50:38 PM
Recently purchased an MCI MC-9 Crusader II on eBay. I'm finding that it is going to need a lot of attention, but I've fallen madly in love with my MC-9 and I'm willing to go the extra mile.

One issue is the Detroit Diesel 8V71. It blows both white smoke on start-up and also black smoke. The other day after I started it up and ran it for a couple of minutes and it "Ran Away" for about 3 seconds. That scared the heck out of me. I don't want to lose my MC-9 with the engine going ballistic.

Haven't heard a lot of positive things about the 8V71 other than it is a very powerful engine; I already know that. It uses a ton of oil and I want to get away from that problem too.

I've talked to many truck drivers and they are all talking about the Cat C-13.

Anyone have any ideas? :-\

Thanks!


Mike
N9EWS
Title: Re: MC-9 / 8V71 woes
Post by: Kwajdiver on December 27, 2009, 01:55:41 PM
Mike,

Welcome to the board,,, I see this is your first post.  I also have a MCI-9 and love it.  I'm not your engine expert, but a lot of guys here on the board will be glad to help.  It will take a while to get all the bugs out of your bus.  Hang in there.... and knock them down one at a time.

I'm sure help is forth coming.

Post some photos of you bus.

Bill
Title: Re: MC-9 / 8V71 woes
Post by: WVA_NATIVE on December 27, 2009, 01:57:50 PM
BK loves them CAT'S you cans ask him and also Tom C. is my first choice for anything engine related.

WVaNative
Title: Re: MC-9 / 8V71 woes
Post by: luvrbus on December 27, 2009, 02:01:38 PM
Mike your 8v71 ran away because of fuel and oil build up from long periods of idling run that baby and don't idle for long peroids may 1 or 2 mintues at most then check the air cleaner if you still have a lot of black smoke have somebody run the rack and set the injector timing and check the injectors one may have blown a tip  and fix your leaks, it blowng black smoke it is not burning oil.
A question for you how much oil is dripping from the air box drains from each side and do you know what oil the PO has in the engine they will smoke,leak more and use more oil with 15/40 oil
The 8v71 will be around when the C-13's are long gone the enjoy your trip.  

good luck
Title: Re: MC-9 / 8V71 woes
Post by: James77MCI8 on December 27, 2009, 02:03:26 PM
I have an 8V71 in my 8 and have no problems with it. The white smoke on start up is normal for a two stroke DD. The black smoke could be caused by a clogged intake filter , incorrect timing or any number of other things. The run away that you described could be caused by the rack hanging. Find you a good two stroke DD mechanic and have the rack run. Others here will be helpful with a diagnosis also.  

Things I have learned here about the two stroke:

1. Do not idle the engine for long periods
2. If you are going to start it. at least take it for a run so that the engine will reach operating temp.
3. Allow the engine to seek its own oil level. Overfilling will result in oil being blown out.
4. Keep the air filters clean.
5. Keep the fuel filters clean.
6 It is a DD drive it like you are mad at it.
Title: Re: MC-9 / 8V71 Woes
Post by: Depewtee on December 27, 2009, 02:21:47 PM
Mike,

Welcome to the board and nice garage!  The bus ain't bad either.  I am fairly new to the board also and have learned a lot from reading what these wise ones have to say.  My bus is an '84 MC9 with a 6V92T.  It has taken some time to get used to the DD, but now I think it is a wise choice for our buses.

Brian S.
Title: Re: MC-9 / 8V71 Woes
Post by: BlueScarecrow on December 27, 2009, 02:24:05 PM
Thanks gang for all your wonderful replies.

When I'm on the Interstate and I get it in 5th gear... the motor flattens out and gets real quiet. I look down at the speedometer and it's at 78 mph. Yow!

I am looking for a mechanic here in Phoenix. And I'd like to be present during the rebuild as I have no experience with diesels, but I would love to learn. I'm a very quick study.

Read a post once where a fella said that if you have an DD 8V71, put your hand in the jamb and slam the door. That will put you in the right frame of mind for driving it. LOL :D

Thanks!


Mike
N9EWS
Title: Re: MC-9 / 8V71 Woes
Post by: James77MCI8 on December 27, 2009, 02:25:14 PM
Nice Bus and garage!
Title: Re: MC-9 / 8V71 Woes
Post by: James77MCI8 on December 27, 2009, 02:26:35 PM
A DD purrs much better than a Cat!
Title: Re: MC-9 / 8V71 Woes
Post by: luvrbus on December 27, 2009, 02:36:41 PM
If you can attend the rally in Quartzsite Jan 21-23 Don Fairchild will be there and tell you what you need before taking to somebody like WW Williams.
If you need a 2 stroke mechanic Berry Machinery in Chandler has a couple of good ones if they have time to work on the bus.
Here in Mohave Valley Az where I live A&A Diesel is a good shop at fair prices I know Andy is good he thinks the 2 strokes were the best ever built.



good luck
Title: Re: MC-9 / 8V71 Woes
Post by: Dreamscape on December 27, 2009, 02:44:47 PM
Nice coach!

You will like the 8v71 once you get it out and drive the heck out of it, that's what they like. They've been around a long time and will be for many years to come. We have one also in our Eagle, it lacks power when climbing long grades but that's the only downfall. It's plenty fast on the straights as you found out. Our blows white and blue until she warms up then it's good to go, black if I have my foot into it. The cost of a re-power is way out of my league, but a rebuild isn't cheap either. Run what you got, have the rack run and check the injectors as others have mentioned. You can burn a lot of fuel for many years for the cost of a rebuild.

I'm assuming since you've had it a short while you don't have many miles behind the wheel. Take it out for a spin and get used to her, she will reward you with years of service. Just use the correct oil, get some manuals, find a good DD mechanic and you'll be happy. Sure you can hot rod it if you have the money, Don's the man for that.

Have Fun,

Paul
Title: Re: MC-9 / 8V71 Woes
Post by: buswarrior on December 27, 2009, 03:56:53 PM
You are a sitting duck to be taken advantage of.

If you get told you need a rebuild, and you will, how are you going to know it's the truth?

And what constitutes a rebuild, in the mind of the guy about to screw you?

As part of your diagnosis, the above mentioned "tune up" procedures will help a reputable shop determine the health of your engine along the way.

You need the advice of a reputable shop, and driving the coach 1000 miles to get to that shop is money and time well spent for a busnut. We have no way of recouping the costs of shoddy workmanship like a commercial operator does.

So, busnuts, where should he take this coach for some TLC?

happy coaching!
buswarrior
Title: Re: MC-9 / 8V71 Woes
Post by: cody on December 27, 2009, 04:04:25 PM
My thoughts are to hit Q and let don check it over, if needed there will be a line of very qualified BUS mechanics ready and willing to stand right beside don and you will get an honest apprasial on the condition, I see it's a church bus, did they tell you how many miles on the rebuild?
Title: Re: MC-9 / 8V71 Woes
Post by: luvrbus on December 27, 2009, 04:17:22 PM
If he wants the bus serviced and a check over take it to Michelangleo of Phoenix they own MCI's and are great people but I don't think they do engine work but there they will let him watch and explain the different systems.
Andy or Bill do you have the phone # I can not find it in the search here.
Mike a word of advice don't take your bus to Desert West or Taylor in Phoenix been there done that.   


good luck
Title: Re: MC-9 / 8V71 Woes
Post by: Busted Knuckle on December 27, 2009, 04:51:12 PM
If he wants the bus serviced and a check over take it to Michelangleo of Phoenix they own MCI's and are great people but I don't think they do engine work but there they will let him watch and explain the different systems.
Andy or Bill do you have the phone # I can not find it in the search here.
Mike a word of advice don't take your bus to Desert West or Taylor in Phoenix been there done that.   


good luck

Clifford,
Funny you should mention Desert West  >:(

They were the lien holder on the first bus we ever owned ('90 Setra S215 HDH) and had it repossessed prior to us buying it. Between them and their agent one of them tried to screw us out of the $15,000 we'd paid and thought they could dup us into paying double in order to receive a clear title. A phone call to the AZ & MO (where thier agent was from) States Attorneys Offices brought a clear title screeching to our door unannounced by FedEx straight from Phoenix less than 48 hrs after the call was made.

I've said it once, and I'll say it again. When it comes to who knows who in the bus world Clifford knows the goods on all of 'em good and bad! (never seen him make a bad call yet!)

So Mike take Clifford's advice and trust your bus with it, and trust me you'll never go wrong listening to Clifford! 

Welcome and enjoy yer bus! And HAPPY NEW YEAR! (now take that bus for a spin and go to Quartzsite and meet up with some of the best busnuts you'll ever meet and you'll have plenty that will give you a hands on education right then & there!) FWIW
;D  BK  ;D
Title: Re: MC-9 / 8V71 Woes
Post by: BlueScarecrow on December 27, 2009, 07:40:14 PM
Thanks to each and everyone of you!

You come across like warm genuine honest people.

Just what the doctor ordered.

See you at Quartzsite!!!

For Busnut Hams, I'll probably be on 146.490

Talk-In for the Quartzfest (Hamfest) is 146.550

Thanks!


Mike
N9EWS
Title: Re: MC-9 / 8V71 Woes
Post by: TomC on December 27, 2009, 07:50:47 PM
If your engine is healthy, at around 50-60 degrees, the engine should blow a bit of white smoke for less then a minute.  Any more means the rings are worn, along with most other parts of the engine.  Also, with blowing black smoke, either your air cleaner is clogged or your injectors are worn out-also with worn rings you can get black smoke even when the engine is warmed up.
My 8V-71TATAIC, will blow some white smoke when cold, but stops in short order.  If you're planning on keeping the bus for a few years, it would be good piece of mind to have the engine overhauled (just replace what's worn out).  Good Luck, TomC
Title: Re: MC-9 / 8V71 Woes
Post by: rv_safetyman on December 27, 2009, 08:19:33 PM
You have gotten good advice.  

I would like to add that you will spend anywhere from $8K-13K for a Detroit rebuild.  It will probably be towards the larger number.  Absolutely DO NOT have "Joe Blow" do a rebuild unless you have you have more than one excellent reference.  

The rebuild should be a last resort.  The steps that folks have given you to try are quite important to finding the true condition of your engine.  

Do not overlook the oil recommendation.  Two strokes require a straight 40 wt oil (lots of threads on the subject - use the search feature).  No matter what, I would change the oil and filters before you take in on a long hard run.  

Watch in your mirrors and see what the smoke looks like.  On a flat highway at normal speeds and perhaps half throttle you should not have much smoke (after you run it HARD for an hour or so).  When you hit a hill and go to full throttle, you will get black smoke - that is normal (most folks drive the hills by the temperature gauge and watching for black smoke - back off the throttle a bit to minimize the black smoke). In addition, on long hills you will want to watch the tachometer (get one if you don't have one) and keep the engine RPM in the higher RPM range (1600 to 2100 - two strokes can not stand to be lugged down)

Might be a good idea to have someone in a car follow you and watch what happens under various condition (will need CB or cell communication).

The only issue with the 8V71 is that it will not have a turbo.  As a result, it will get a bit puny at altitude.  Some folks have added a turbo and intercooler for a really great power plant.

Jim
Title: Re: MC-9 / 8V71 Woes
Post by: RickB on December 27, 2009, 08:46:33 PM
Along with all the other excellent advice here I would like to hear more about your runaway symptoms.

Keep in mind that your fuel shuttoff is air actuated so if you tried to shut your motor off with less than 90 lbs of air it will not shut off. So did your motor refuse to shut off or did the rpm's climb like you were pushing down on the pedal progressively? Had you just started the motor or was this after a prolonged idle period. A few years ago my old bus had a sticky rack that would not let the motor return to idle after I let my foot off the pedal needless to say that was an unsettling feeling. That felt like a runaway motor and scared me badly.

If your handy I would recommend you remove the blower intake and get a good look at your blower airbox. It should be clean, if it isn't it is time to have it gone through or purchase a rebuilt and also heed the earlier posts advice about your airbox drains. A runaway engine is a very expensive problem to have. Have you checked your emergency air shutoff and made sure it's operational? Use a compressor to air the system to around 100lbs and flip the switch. If it's working correctly it should flip down and you can reset it afterwards. It's kind of like a air actuated mouse trap.
But remember none of your shutdown mechanisms will work without air.

Welcome to the board and have fun in Quartzite.

Rick
Title: Re: MC-9 / 8V71 Woes
Post by: Kwajdiver on December 28, 2009, 02:39:23 AM
The guys at  Michelangleo of Phoenix are great.  They bent over backwards to help me.  They have a trailer full of MCI-9 parts.  They let me stay in the bus a couple nights in their yard.  The shop rate is very good.  Do I have the phone number,,,, hummm, it's in the bus... 7000 miles away.  I will see if I can find them online tomorrow.  If not, believe I can find the address.  I know, they are just off the interstate, south of the airport.
Tell them Bill with the big blue bus said hello.

Bill
Title: Re: MC-9 / 8V71 Woes
Post by: PSmith on December 28, 2009, 06:00:43 AM
Welcome Mike,

I've got an 8v-71N in my RTS and I like it ! Like a TIMEX !   

I don't post much, but I've been a lurker for a long long time. Got my bus in '97.

I'll be in Quartzsite Jan 22-24 for the fun.  Also a Ham - KC7JD and I'll look for you on whatever freq. was in your post ;D

I'm looking forward to putting faces to the names I've seen here for years!

Again, Welcome Mike
Phil in Prescott
Title: Re: MC-9 / 8V71 Woes
Post by: Kwajdiver on December 28, 2009, 08:44:10 PM
Michelangleo of Phoenix
602-340-0018

1315 East Gibson
Building C.
Phoenix, Az

They are between,   S 7th st and S 16th st.

They even let me help work on my bus... Now find me a shop that will do that..... ;D

Good Luck,

Bill
Title: Re: MC-9 / 8V71 Woes
Post by: cody on December 28, 2009, 09:55:44 PM
I'm not a good mechanic, actually I'm a very poor mechanic but I've been following this thread with great interest, from what I'm hearing I really don't see a broken engine yet, what I do see tho is an engine in great need of some maintance, I've got a gut feeling the air filter is plugged, probably the fuel filters are bad too, I've also got a gut feeling the engine is full of 15w40 or maybe worse, I think maybe some bearings should be repacked and some grease fittings should be lubed and I think we've got another busnut that is going to enjoy his hobby with probably no more problems than what we are all accustomed to as routine. Correct me if I'm wrong but lets try some routine maintence and have a BUS mechanic look it over before we panic, does this make sence to anyone besides me?  Unless a person has some deep pockets and plan on putting a lot of miles on the bus each day, even a bus with a somewhat weak engine will usually give a lot of great service for what a normal busnut (can I say normal) would give it for a long time.
Title: Re: MC-9 / 8V71 Woes
Post by: JohnEd on December 28, 2009, 10:58:29 PM
Cody,

Great advice from all.  I think Mike's greatest opportunity is to meet Clifford(luvr) and Don Fairchild and the rest.  Get names and numbers and start your Rolodex.

I am no heavy equip op nor am I a trucker and when I buy my bus it will make it an even "once" that I have owned a diesel.  But I have been a shade tree mech for long enuf that I can at least understand MOST of what i am told.  Now that stuff about lugging a DD two stroke is so thick that you must have gotten the message within mere hours of tuning in to the board.  So I got a chance to drive a 8V71 for the first time this past summer.  Turns out I knew NOTHING and was doing almost everything wrong.  I started off fine....shifted into second without a hitch and could up shift to third and down shift to first with a min of difficulty.  Besides slamming my hand in the door and also, for insurance, got myself groin kicked, I LUGGED THE FRIGGEN ENGINE.  Many time Mike and yes it was embarrassing.  You need to take a check out ride with a pro.  You can ruin a 2 stroke in 1,000 miles but some will say 942.5 and others will swear it will go 1007 miles if abused.  But who is counting?

Get a filter minder and make that your very first equip purchase.  Then you will be able to SEE if your filter is OK ans save a hundred bucks or so. 

Having 2 stroke approved oil in it is CRITICAL.  Have the oil in the engine now analyzed....$30.  That will tell you what it is and if it is wrong you need to do other stuff.  Lots of miles on 15 w 40 as verified from the analysis with bearing metal in the oil would mean turning in new bearings FIRST after the minder.  Analyze your coolant also.  Rads are a grand or more.

Take the bus to a car wash and flush out the fins from the inside out and outside in.  That has solved many overheating problems. 

How long should you try to run it if it is overheating?  In a 92 I think 215 means thousands of dollars worth of damage but the 71's are more durable, I am told.  So what does that mean????Maybe they will go to 217 degrees before horrific damage....don't know.  I am sure you got the drift.  They have auto shutdown circuits that actuate for both HI temp and low oil pressure and some have a low oil level start disable. 

Get the book for the engine and bus ASAP.  Maybe QS will be a source.

Wish we could meet at QS.  I hope to be in your shoes in a year or so.

John
Title: Re: MC-9 / 8V71 Woes
Post by: Slow Rider on December 29, 2009, 06:24:22 AM
The only caveat I would add to this is be carefull with the pressure at the car wash.  Depending on the age and condition of the radiator you can damage it.

http://www.busconversions.com/bbs/index.php?topic=10372.0 (http://www.busconversions.com/bbs/index.php?topic=10372.0)

That thread speaks of pressure washers specifically but ....  just be carefull, a new radiator is probably around 4K.

Frank
Title: Re: MC-9 / 8V71 Woes
Post by: Don Fairchild on December 29, 2009, 09:27:21 AM


The red flag for me is Church owned. Churches suffer from a lack of maintenance as a rule. All of the suggestions have been great, so I will repeat them. Before you make any decisions do a full service then run the bus up and down the road at temp for a time then check it out to see whats going on with it. ( Think Phoenix to Tucson and back )

Let us know how it goes and we can help you.

Don
Title: Re: MC-9 / 8V71 Woes
Post by: luvrbus on December 29, 2009, 09:54:59 AM
Don, Phoenix to Quartzsite is about the same mileage I would like to see him have the oil , the air filter and fuel filters changed before the trip what do you think ? that being a church bus no telling what it has for engine oil .
? for you did you find out the price of a set of rebuilt rockers and shafts for the 8v92 for me.




good luck 
Title: Re: MC-9 / 8V71 Woes
Post by: Eagle Andy on December 29, 2009, 10:13:52 AM
Yup Iam will bill micheiangleo in phx is a great shop. Good service and great owners , Even offered me a job when I was there lol . Bill I think we met there you were just getting ready to pull out when I showed up and you showed me you Bus .  Andy
Title: Re: MC-9 / 8V71 Woes
Post by: Kwajdiver on December 30, 2009, 01:47:02 PM
Yes, Andy, believe you are correct.

Mike, keep us informed how your doing with the bus.

Bill
Title: Re: MC-9 / 8V71 Woes
Post by: Jriddle on December 30, 2009, 05:02:58 PM
Welcome Mike
Great advice here. Get it serviced properly then run the $$$$ out of it before you send the big money.

My Thoughts John
Title: Re: MC-9 / 8V71 Woes
Post by: BlueScarecrow on December 30, 2009, 05:58:26 PM
Hi Gang!!!

Thanks for all of your wonderful advice.

Yep... you hit the nail on the head. There is 10W 40 in it. Saw it on the shelf at T&A and the guy said that is what everybody is using. I goofed!

Ok... so I'll change the oil about a week before Quartzsite and I'll beat the hell out of it on the way up. That should be a good test.

Somewhere along the line it's loading up with oil, and after warming up the white billowy smoke (not steam) goes away and there is a light blue smoke when I'm driving down the road.

I just don't know enough about diesels yet to figure out just where the oil is collecting.

What's a good day to get to quartzsite when Don is there?

Thanks!


Mike
N9EWS
Title: Re: MC-9 / 8V71 Woes
Post by: Van on December 30, 2009, 07:54:39 PM
I'm with Clifford on this. Check the air filter and fuel filters replace if not done already,FWIW good luck see ya in QAZ ;D
Title: Re: MC-9 / 8V71 Woes
Post by: JohnEd on December 30, 2009, 08:04:30 PM
Have the 10W40 analyzed.  You need to know if there is traces of metal and what type of metal.  That  can also tell you if you have air leaks into the engine.....that AZ sand takes care of everything in short order.  Also shows coolant leaks that are starting and not clearly evident looking at the oil.

I am not a doomsayer.  I am opt and encouraging.....truly.   You do want to know what the situation is and Don and Clifford can tell you your next steps from the info you provide.

I "think" that you are supposed to see blue(oil burning) smoke if it is loaded with 10w40.  It should also blow that stuff all over everything including your toad.  Yuck!

It was mentioned but I will repeat:  If you are a gallon low after a few hundred miles don't fill it up at that point.  Drive it a couple hundred more miles and recheck.  If it is holding that level then just keep it at that level as though that were full.  I must have heard that here 50 times.

And YES I do envy you :( ;D ;D ;D   I'll repeat :( ;D ;D ;D

John
Title: Re: MC-9 / 8V71 Woes
Post by: Dreamscape on December 30, 2009, 08:31:46 PM
Change the oil/filter and drive the darn thing! Check oil level after a couple of hundred miles, only add if over one gallon low. Make sure you let it sit for at least 30 minutes before checking to make sure it's drained down. Don't try to keep it topped off, let it find it's own level. Ours runs well at just under a gallon low, other useage is due to a few leaks! ;D

Paul
Title: Re: MC-9 / 8V71 Woes
Post by: Van on December 30, 2009, 10:24:20 PM
51? LOL! :D
Title: Re: MC-9 / 8V71 Woes
Post by: JohnEd on December 30, 2009, 11:39:41 PM
Mike,

5th  GEAR???  Is it a stick?  I guess you would count that way with the converter locking being a "shift".

I have met Knuts with automatics that they select gears manually with.  They drive with the tach and don't trust Alyson in the least.  Can't be true for all buses but I took it to heart.  I have it on unimpeachable source that "most" of the Pre's with autos are in need of overhaul at 150K miles.  Seems the Alyson is not able to protect the engine fully and the bus needs to be "driven" and not just "steered".

I wish you all manner of good fortune on your travels and journey,

John
Title: Re: MC-9 / 8V71 Woes
Post by: belfert on December 31, 2009, 06:02:03 AM
A lot of busnuts would recommend shifting a 740 by hand.  I recall BW recommending that anyone being paid to drive a bus with a 740 shift it by ahnd.  It seems silly as the reason I buy a vehicle with an automatic is so I don't have to shift it.

I have an Allison B500 in my bus and I let it do ths shifting.  To me at least it seems to shift at the right times.  The only time I manually shift it is if I need more bite with the Jake Brake.
Title: Re: MC-9 / 8V71 Woes
Post by: Ed Hackenbruch on December 31, 2009, 06:39:52 AM
 And i am just about opposite of Brian.  The only time i don't manually shift my 644 is by accident......usually distracted by something and not paying attention to my rpms.  :o
Title: Re: MC-9 / 8V71 Woes
Post by: JohnEd on December 31, 2009, 10:33:30 AM
I pondered this for a while and a light bulb went off one day when reading a post about 740's.  Not that I know personally, be sure, but this was the gist.  The discussion was about the shift points of the Allison and that those were "adjustable" and could be reset for up and down.  Also that the forced down shift function could be disabled by a number of things going out of whack over the years.  Wear and tear and deferred maint and ignorance also set the stage.  My conclusion was that some of these beasts actually NEEDED to be manually shifted to stay in the ball park of acceptable revs and load while others didn't need it as much.  As well, the Allison was not the genius some think and looking down the road the driver was very often more clever that the trans. at staying in the power band and not loosing speed going into or staying on a grade.  I think many, rather than get the big buck overhaul, installed a tach and took charge.  It seems that "all" professional drivers shift the auto either manually or pulse the throttle to "force" shifts that the "brain" can't be programed to make at whatever point.

I personally see the Allison as the way to a torque converter to allow starts on hills by rookies, faster up shifts, and even possible down shifts and getting some of the abuse of the engine/drive train relieved so things last longer.  Access to a "retarder" option might be a factor in San Francisco new purchases.

I agree with BW, the driver needs to be involved in the operation of the Allison.  Course, if you never leave Nebraska, all bets are off.  Its dealing with the grades that are the problem.

And FINALLY....the clincher:  Really heavy duty D mech and shop owner told me that "most" Pre's had bad engines at 150K miles due to lugging.  Those wonderful behemoths are bought and driven by big buck Dudes that get an ego sensitive check ride and then "steer and stab" the bus till they sell it which is usually when some clever Bunny tells them they need a $20K overhaul.  They, the engines, take that stuff for about 150K....I am told and they never even spill a glass of water on the dash.  "The dealer said it's time we bought a brand new bus Martha."  And that "low mileage" deal goes on down the road.  So I am told by the guy that gets the $20K to correct the damage and shared that data to HELP me not HURT myself.  Generous Dude!  If Mr. High Finance was driving YOUR bus you would probably leave your finger prints swelling up on the back of his head cause a savvy driver gets 450K miles out of an 8V92.

And, please Dear Lord, I am not putting down any that actually own one of these beasties and can do it their way by rights.

John
Title: Re: MC-9 / 8V71 Woes
Post by: Depewtee on December 31, 2009, 01:22:20 PM
I have an Allison 740 in my '84 MC-9 with 6V92T and I let it shift 1st and 2nd, but I am in charge of 3rd, 4th, and 5th.  If not, it has a tendency to buck a lot at those shift points depending on the grade, speed, and throttle position.

Brian S.
Title: Re: MC-9 / 8V71 Woes
Post by: cody on December 31, 2009, 01:31:51 PM
Drive them hard, easy for me, I'm married, I have road rage, parking lot rage, walmart rage, etc, mine likes the rpms up a bit.
Title: Re: MC-9 / 8V71 Woes
Post by: RJ on December 31, 2009, 03:03:14 PM
BrianS -

If you have a HT-740, it is a four-speed gearbox, not a five.  What you're experiencing as a "shift" is, in reality, the torque converter locking up.

IIRC, the sequence is 1C - 2C - 2L - 3L - 4L, where C = converter unlocked and L = Locked converter.  (I may have the lock-up sequence wrong, if so, me bad!)

Running around town, if you just leave the shifter in 3rd, you'll avoid a lot of the hunting back 'n forth between gears.  Obviously, once you hit the highway, you upshift it to D.


Belfert -

IIRC, you've got a S-60 mated to your B500, right?  The torque curve on the 60s is vastly different than the two-strokes, so it can be lugged down a lot lower rpm-wise before downshifts are necessary.

That being said, however, it is still advantageous to downshift manually when pulling grades to keep the engine near the top peak of the torque curve.  By doing so, you also keep it in a range that helps cooling, too.


Mike (Scarecrow) -

Change the oil to Straight 40wt, CF-2, 1% or less sulfated ash.  Chevron Delo 100, Shell Rotella T, Exxon XD-3 and Texaco Ursa are three common and popular brands.  Available thru a local petroleum distributor, comes six gallon jugs to a case, in five gallon pails, or 55 gallon drums.  Takes approximately seven gallons for a complete oil/filter change on your MCI.

Don't fire up the engine simply to "warm it up" without driving it.  Great way to build up sludge & gunk.  Far better to simply start it, and as soon as the air pressure is up to 120, drive it off.  And then drive it enough to bring everything up to operating temps.

Not sure where you're located (hint - put your city/state in your signature line), but yes, a several hour run to Quartzsite the end of next month at 65 - 70 mph will blow a lot of the gunk out, especially with the correct oil in the 8V.  By the time you get to Q, it may be running nice and clean, so you may not need as much hand-holding!



JohnEd -

Entertaining and informative post, and, regarding the Big Buck Dudes and their Prevosts, probably "right on".

Greyhound was the first non-transit bus company to really put the Allisons to the test in revenue service, back in the early '70's.  Once they found out that the slight fuel mileage penalty was less than the cost of rebuilding clutches, the handwriting was on the wall.

Sadly, there's a whole generation of drivers out there that have no clue how to drive a stick-shift coach, they just stab 'n steer.  And even then, they have no clue about manually shifting the automatic for certain conditions.  Sad. . .

Time marches on, I guess.

FWIW & HTH. . .

 ;)
Title: Re: MC-9 / 8V71 Woes
Post by: Lin on December 31, 2009, 04:58:25 PM
John and RJ,

I would like some clarification on this lugging thing.  My 8v71/Spicer combo when running 2000 rpm in 1st, meshes perfectly to about 1100 rpm in 2nd.  Hence, it would seem that one must run at lower rpm when building speed.  I don't remember exactly now, but the rpm differential becomes narrower as you climb the gears.  2000 rpm in 3rd is just over 1400 rpm in 4th.  So I guess the point is that one should not try to cruise or climb below 1600rpm in a 2 stroke.  Am I missing something here.

Further, I have been looking into buying another bus, the one we are trying to make a deal on is a Prevost.  So I may be becoming sensitive to slights against Prevost drivers.  Anyway, the PO was the 2nd owner, and he had it for 14 years.  It had an inframe at about 160,000 so one might say that there is something to your observation that the engines do not last as long as they could due to poor driving habits.  However, that engine was about 18 years old when it was rebuilt.  My non-expert opinion has been that time counts as much as mileage.  When seller says that the engine was rebuilt only 10,000 miles ago in 1989, I consider it an old engine.
Title: Re: MC-9 / 8V71 Woes
Post by: luvrbus on December 31, 2009, 05:12:03 PM
You hit the nail on the head Lin Detroit has a process you do when storing a engine for over 30 days and no bus nut pays any attention to it.
You can fog a rebuilt and never run it and it is good for years 
Are you buying the Prevost in Texas or another. 

good luck
Title: Re: MC-9 / 8V71 Woes
Post by: Lin on December 31, 2009, 05:38:41 PM
Clifford,

That's the one we want to buy.  The only issue is that I don't want to pay for it until I get there.  The seller refuses to take a deposit since he wants to be free to sell it.  His experience tells him he can not count a deposit as a sale.  He is now going through it and fixing some things that would be added onto the price.  He says it will be ready to go by the end of next week.  I plan to fly out then.  There are some places on the back and front that have peeling clearcoat.  I was hoping to get those faces sanded and re-coated.  He has offered to sand and re-coat the entire bus from the bottom of the windows up for an extra $1500. after I buy it.  It will certainly enhance the appearance and sounds like a good price.  The big problem is that it just seems too nice to let me inside.  I don't remember, did I send you the pictures?
Title: Re: MC-9 / 8V71 Woes
Post by: JohnEd on December 31, 2009, 07:16:43 PM
Clifford,

You are just so much info.  Really!  FOG????  I can guess what that means but could you do that for the 4 months it would sit over the winter?  How long would the down time have to be to warrant a FOG job  and I am not being funny. 8)  What is the process to UN FOG or DE FOG?   Now that was a sorta joke but not really.

This leads me to a really painful observation.  I let the RV sit for w "few" years and only gave the engine its annual ....run till sorta warm.  I took the front bearings of to check the grease cause Da  Book said to and I found "RUST" on the upper surface of the bearing and inside the hub.  RUST!  Cleaned the hub and put BOAT wheel bearing grease in there.  Recently I read on my Black Powder board that petroleum base products don't actually like metals.  Testing various "gun lubes and such" the metallurgist, nice guy by the way, hammered common nails flat and dipped them and then stood them up in a controlled 80% humidity.  You can intuit a lot but there were some serious surprises for me.  Bees Wax did poorly, and all the pet base stuff gave up and let the nails rust.  He had some mixtures that did well but you would never put Caster bean oil in your crank case and some of the other stuff was also not suitable but it was great for guns and such.  Lanolin was a winner so I guess we have solved the mystery of "why don't sheep rust?".  He did this test on all sorts of concoctions but one was conspicuous in its absence.  SYNTHETICS!  Recently I read that Syn has an affinity for metal and using it to lube isn't just avoiding wear but making absolutely sure you don't start DRY no matter how long it sits.   So: syn is a must because....It is slipperier and gives better MPG, runs cooler in engine, lasts longer between changes AND FINALLY....gives you an extra 300K miles between overhauls (150 to 450K miles).  Well, GOSH, any one of those would be a good reason to switch over all by itself. :P ::)  Seriously....is that true?

Thanks,

Clifford,

John
Title: Re: MC-9 / 8V71 Woes
Post by: cody on December 31, 2009, 07:30:39 PM
At some point before I croak I want to build the ultimate conversion,w ith all the goodies, I have no idea what that is yet but I'll figure it out lol.
Title: Re: MC-9 / 8V71 Woes
Post by: luvrbus on December 31, 2009, 07:45:25 PM
JohnEd, they make a fogging oil used a lot in the marine world has been for years I don't fog mine but I do follow most DD instructions if the bus is going to set for 90 days.
In all fairness to you and engine milage the 2 stroke will live as long as any engine in a bus.
I do not know why but engines in buses have short lives compared to over the highway truck and you would think it would be the oppsite.
People at Stewart and Stevenson have told me 400,000 miles is the average life of a 60s in a bus.
Speaking with folks at Cashman Cat they say 300 to 400,000 for the C-12 or C-13 in a bus the people at ABC say 200 to 300,000 for Cummins in the Vanhools and I believe the guys, at ABC every time I stop to visit a friend at the Dallas yard they always have 2 or more in the shop with engine failure same at Stewart and Stevenson in Houston they always have a yard full of buses with bad engines.
Forgot to mention when in Phoenix last week the Volvo dealer where another busnut works they had 3 H-45 with the D-13 very low mileage with blown engines I laughed and told him looks none of the engines with 13 as model number are working out
Now that will keep you busy trying to figure that out LOL have a happy New Year John and good luck
Title: Re: MC-9 / 8V71 Woes
Post by: JohnEd on December 31, 2009, 08:41:09 PM
Now that will keep you busy trying to figure that out

Well Clifford, facts be known, I have been kept a whole lot bussier by a heck of a lot less.  Mostly that involved women, though.

Back at ya,

john
Title: Re: MC-9 / 8V71 Woes
Post by: bobofthenorth on December 31, 2009, 09:19:55 PM
We used to leave a whole yard full of diesel engines sit for at least 6 months and most of them for 10 months (only ever used them for 2 months in the spring).  Just because we did it doesn't make it right but we sure never even thought about fogging them down and there's a whole industry that we were just a tiny part of who does it that way.  I routinely fog my boat engine down but its a gasser and its always in a wet environment.  I run it hard for 3 months, change the oil, fog it down and let it sit for the other 9.  But it never crossed my mind to do that to the bus.
Title: Re: MC-9 / 8V71 Woes
Post by: Ed Hackenbruch on December 31, 2009, 09:52:56 PM
Lin, i just saw an older Prevost for sale here in Yuma. Did not look at it yet so do not know the price or year.  I see you are in Joshua Tree Ca.  Do you know Jim Craig?
Title: Re: MC-9 / 8V71 Woes
Post by: RJ on December 31, 2009, 11:33:42 PM

I would like some clarification on this lugging thing.  My 8v71/Spicer combo when running 2000 rpm in 1st, meshes perfectly to about 1100 rpm in 2nd.  Hence, it would seem that one must run at lower rpm when building speed.  I don't remember exactly now, but the rpm differential becomes narrower as you climb the gears.  2000 rpm in 3rd is just over 1400 rpm in 4th.  So I guess the point is that one should not try to cruise or climb below 1600rpm in a 2 stroke.  Am I missing something here?



Lin -

First, the gear ratios in the MCI Spicer are slightly different than the Spicers in the GMCs, as is the rear axle ratio, but the powertrain engineer's results are pretty close to the same for each.

In stock "bus" trim, the 8V71 was set up for 275 hp @ 2100 rpm and 770 ftlbs of torque @ 1200 rpm.  Standard cam timing, N60 injectors.  GM Spicer transmission 4th ratio 1:1, bevel gear ratio 0.808, rear axle ratio 4.125:1 (overall = 3.333:1)  In the case of the 4106, 4107 and 4108 models, they were set up for 60 mph @ 1650 rpm using tires that turn 495 revs per mile.

Somewhere I have a HP/Torque graph for this set up, not sure if it's electronic or hard copy buried in a binder.  Anyway, IIRC, the torque builds rather quickly, peaking at 1200, then staying fairly flat until about 1800, where it begins to fall off, but gets "passed" (if you will) by the HP curve, which peaks at 2100.

So, the old adage applies:  Torque gets you going, HP gets you top speed.

Now, to translate that into real world language, yes, you start at the lower end of the rpm/torque range as you're building speed, and at the upper end of the rpm/torque/hp curve to maintain road speed.

Wish I could find that graph, but IIRC, there's a "sweet spot" around 1700 -1800 or so where the torque curve and the HP curve meet/cross.  This is the point where the engine just hums along happily all day long, running on the flat or pulling a grade.

Have you noticed, by chance, that the simple four-speed in our coaches really is well suited for our (relatively) light-weight vehicle, based on it's original design criteria (revenue service)?  First gets you going.  Second is used for those city blocks and residential neighborhoods where the speed limit is 30 or under.  Third is perfect for the suburban four lane routes with 40 - 45 mph speed limits, and finally, fourth gets you comfortable on the interstate.  And that "tall" reverse?  Hey, 99.9% of the time, it was used for backing out of a flat stall at the local bus depot, not trying to wiggle into an uphill campsite at Oh Dark Thirty.

A final thought on lugging.  With the two-stroke Detroit, the general consensus is that if you're pulling a grade and you see black smoke out the exhaust, back out of the throttle.  If you can still maintain your road speed, you're ok.  But if you back off the throttle to clear the smoke, and your road speed starts falling off, then it's time to downshift.  You want to keep the engine in that "sweet spot" on a partial throttle, where if you step on it, you'll get some acceleration, but it will still pull w/o having it floored & smoking black.

(The problem with the non-electronic Allisons, btw, is that when driven w/o manual control by the driver while pulling a grade, they will often downshift too late, bringing the engine so low on the torque curve that it cannot recover, and another downshift becomes a necessity.  And at that point, should it not downshift again, guaranteed you're going to have an overheated engine.  I believe the DDEC/ATEC combination is smarter, perhaps Buswarrior can elaborate more on this.)

Clear as mud?

FWIW & HTH. . .

 ;)
Title: Re: MC-9 / 8V71 Woes
Post by: Lin on December 31, 2009, 11:59:39 PM
RJ,

Thanks for the explanation.  

Ed,

No, I do not know Jim Craig.  Is he here in this area?  What is his name on the board?  Thanks, I would love to meet a compatriot here.  We could encourage each other's foolishness.  By the way, I was in Yuma last week (busless).  Is that your home?
Title: Re: MC-9 / 8V71 Woes
Post by: Ed Hackenbruch on January 01, 2010, 09:01:32 AM
Lin,  Jim is on the MCI board as jtmonza.  He has a 5A, a Flx, and several ultravans.  Really nice guy, and yes, he is in your area.  We have a 5A that we fulltime in.  For the last 5 winters we have called the Foothills home. Summers, i work up in the Seattle area usually, although this year i was on the east side of the mountains near Ellensburg, and will probably be there again this summer too.
Title: Re: MC-9 / 8V71 Woes
Post by: Lin on January 01, 2010, 09:07:02 AM
Ed,

Someone mentioned to me that there is a guy with several buses a couple of miles for us.  That must be him.  Thanks
Title: Re: MC-9 / 8V71 Woes
Post by: Ed Hackenbruch on January 01, 2010, 09:23:28 AM
Lin, i was only at his place once a couple of years ago to get a few parts and I can't remember what street he is on. He is on the uphill side of the hiway.  His place is on the left as you go up the street and is fenced so you really can't see what is out back if i remember right.
Title: Re: MC-9 / 8V71 Woes
Post by: buswarrior on January 01, 2010, 10:13:01 AM
I suppose from this point in history looking back...

The Allisons, 740/730 etc and their controls were very simple, mostly/all mechanical, some/most/all having no decision making capacity. The revs reached a certain value, or with an ATEC, some consideration for throttle position, and it shifted, whether that was good for anyone or anything or not. And they all shifted differently.

Now, put into perspective that the alternative was a 4 or 5 speed stick shift.

All of them mated to an excellent, for its day, engine, which did not know enough to meter the fuel as the load increased, it just poured the coals on like its mechanical bits were designed to do, all the way to suicide, if allowed. Again, no decision making.

And let's stop kidding ourselves, drivers then were no different than drivers today. Get away with whatever you can, and skills were all over the map. Some with skills and pride, some that should have been put in jail. The only difference is we have more time watching from then to today to get jaded and more time to forget the details and romanticize the bits we liked.

In revenue service, nobody cares, just get the thing down the road. Did it go far enough between breakdowns that we are still profitable? And the profit in the transportation business was a lot fatter in those days, so more abuse could be afforded... perhaps a reason these things are more thought of today?

Anyhow... leaving a 740 to downshift on its own climbing a hill has a bad habit of producing a much harsher shift or bang, which is less than nice to the passengers. And as RJ noted, by waiting for a deeper RPM drop before shifting, the RPM in the next lower gear is already down from peak HP. Your terminal velocity going over the top may be slower.

The Allison did at least downshift, which made it impossible for a careless or unskilled driver to refuse to downshift and damage the engine with huge piston temps as it lugged down. In that regard alone, the Allison paid for itself. Even at every corner, making the turn on the roll and carelessly leaving it in the now too high a gear that was being used on the approach and forcing the engine to smoke its way out of sub idle rpm takes its toll.

I am always suspicious of readings on dashboard gauges, and put little stock in their info. In fleet service, a matched set of 10 coaches will show you different RPM and speeds and temps and pressures for any given condition. and, your automobile is the same, the gauges are all over the map, you just happen to own one example.

Who has the gear ratios for the Spicer 4 and 5 speed transmissions? With those, we can work out the relative readings you want to see on your gauges, if they are at least measuring consistently, if not accurately.  IIRC, the 5 speed would drop from someplace 2100 to 1500 on each shift, but that was long ago, before I paid proper attention to these things.

happy coaching!
buswarrior

 
Title: Re: MC-9 / 8V71 Woes
Post by: bryanhes on January 01, 2010, 10:54:10 AM
BW,

Here are the gear ratios on a Spicer 4-speed Model 7145VK.

Angle Drive Gears- 0.808 to 1
1st- 4.28 to 1
2nd- 2.50 to 1
3rd- 1.50 to 1
4th- 1.00 to 1
Reverse- 3.56 to 1

This is out of my maintenance manual X-6814.

HTH,
Bryan
Title: Re: MC-9 / 8V71 Woes
Post by: JohnEd on January 01, 2010, 11:15:39 AM
GREAT THREAD!
Title: Re: MC-9 / 8V71 Woes
Post by: Lin on January 01, 2010, 11:18:08 AM
I must say that I disagree about the 4 speed Spicer being a good application to even old Greyhound Service-- not in mountain/hill country anyway.  I think of it as another initial cost compromise made at the expense of good design.  True, the high reverse was okay for getting out of bus stations, but really I doubt that they had any reason to need to back up at 15 mph.  For hills, they really should have had a granny gear for starting on grades.  Imagine being in stop-and-go traffic on the Grapevine due to an accident up the road.  What would be the MPC (miles per clutch).  I realize that the pros could handle these things a lot better than I, but the physics of getting started on a 6% to 8% grade with a 4.25 gear ratio is just not friendly.  Having once got stuck on a hill that my 8v71 just could not handle with that gear ratio, I am particularly paranoid about it happening again.  I see it as a 5 speed being about ideal with the extra gear being below the current 1st.  The other forward gears could be exactly the same.  Reverse could about match the new first.  Thanks
Title: Re: MC-9 / 8V71 Woes
Post by: buswarrior on January 01, 2010, 12:39:24 PM
When is someone going to invent a BBS posting screen that doesn't lose all your $%&*@ work if you happen to click for Google and leave the page???

I will recreate it all again after retrieving the mouse from the fishtank...

I need a scotch. Blame the equipment, not the operator...

Stupid damned BBS software.

happy coaching!
buswarrior
Title: Re: MC-9 / 8V71 Woes
Post by: lostagain on January 01, 2010, 12:46:05 PM
Really funny BW... except when it happens to me sometimes, BTDT.

JC
Title: Re: MC-9 / 8V71 Woes
Post by: Depewtee on January 01, 2010, 12:57:28 PM
BW,

On longer posts I find it useful to type the text into Microsoft Word and then copy/paste to the BBS.

Brian S.

 
;D ;D Mouse in the fish tank ;D ;D
Title: Re: MC-9 / 8V71 Woes
Post by: Ed Hackenbruch on January 01, 2010, 01:46:22 PM
BW, i know your pain.......its happened to me about 4 times today on different sites. >:(

 Lin,  i stopped and looked at that Prevost.   Its a 1983, 40' with an 8V71 and 6 speed tranny.  It is basically a shell, has been gutted. Asking almost $16,000  for it. Looks like a church or ministry may have owned it.  Looks a little rough to me. Rode hard and put away wet? 
Title: Re: MC-9 / 8V71 Woes
Post by: buswarrior on January 01, 2010, 02:37:08 PM
Ok, with these GM transmission ratios,

The 1-2 shift is a 41.6% change, so drops from 2100 to 1226
The 2-3 shift is a 40% change, so drops from 2100 to 1260
The 3-4 shift is a 33.3% change, so drops from 2100 to 1400

So, there is effectively no overlap of gears for a given road speed, except a bunch of mph between 3 and 4. Just like the owners of these coaches tell us!

Or, said another way, road speed dictates which gear you have to use.

And this also shows what might be wrong if you advance time/bigger injector an 8V71 in a GM, moving peak torque up to 1400 rpm from standard timed 1200 RPM, you drop the engine below the power on shifts 1-2 and 2-3, as well as the bottom of all 4 gears is in the toilet a lot longer, road speed wise.

You may have also heard GM owners discussing hill climbing, particularly the 4104 owners, comment they have to give up on 3rd gear, and drop road speed way back to grab 2nd and plow up the hill against the governor with lots of available power, but not enough power to pull with 3rd. They would love to have a gear in the middle, and the numbers show that.

Keeping the technology in perspective, remember that the multi-speed transmissions of the same day required multiple stick shifts to control the auxiliary boxes, and all manner of wild shift patterns and order of using which stick into which position.

The simple 4 speed would have been well regarded, and cut a wide swath across the drivability needs of a line run motorcoach. And these auxiliaries had reliability issues.. the old men I have known who drove those, may remember those days fondly, but do not want to drive those beats anymore!

Once you have equipment, there is a business need to observe the inertia of “run what you know”, keep spec’ing the same thing.  There was the bonus of the higher HP of the 8V71 helping hide the wide gear spacing, and the driver’s had become familiar with the 4 speed and what to do to stay employed.

Now, fast forward to today’s technology, the 18 speed transmission of today (and the top 8 of a 13speed) are spaced  approximately 17% apart, giving a trucker a lovely amount of choice as to which gear to use for a given road speed. Under a 2100 rpm downshift, the 18 speed would only drop 350 rpm or so.

Has anyone looked at whether any of those lovely 6 speed transmissions in the medium duty trucks would fit behind the bevel gears on a GM?

And who has the ratio for the 5 speed, so we can show the incremental improvement over time?

happy coaching!
buswarrior

Title: Re: MC-9 / 8V71 Woes
Post by: belfert on January 01, 2010, 06:30:13 PM
When is someone going to invent a BBS posting screen that doesn't lose all your $%&*@ work if you happen to click for Google and leave the page???

Why not open another browser or another another tab in your browser if you need to visit another web site?

I suspect it is as much an issue with web browsers as the BBS software, but I really don't know.
Title: Re: MC-9 / 8V71 Woes
Post by: buswarrior on January 01, 2010, 06:48:38 PM
you have to remember to open another tab before clicking go on the handy Google toolbar thingy...

After you forget, when you click back, your reply post window is nicely blank for you to start again.

happy coaching!
buswarrior

Title: Re: MC-9 / 8V71 Woes
Post by: NewbeeMC9 on January 02, 2010, 04:39:17 AM
you have to remember to open another tab before clicking go on the handy Google toolbar thingy...

After you forget, when you click back, your reply post window is nicely blank for you to start again.

happy coaching!
buswarrior



Some of us need new tabs for our brain ;D,  some of us have too many tabs ;) :D and what was I typing about ???
Title: Re: MC-9 / 8V71 Woes
Post by: BlueScarecrow on January 02, 2010, 10:01:58 AM
Ok... I think I have figured out what my problem is... My Blower Seals are shot and oil is leaking into the blower. And I have really low Oil pressure, but that might be the 10w 40 oil. Will be doing an oil change this week.

I'd love to include some pictures, but when I click on the Insert Image button [img][img] appears. What's up with that? I also have Avid Media Composer and Sorenson Squeeze for making Flash videos. Anybody know how to include those in a post? ???

Greatly appreciated.

Thanks!


Regards,
Mike
N9EWS
Title: Re: MC-9 / 8V71 Woes
Post by: buswarrior on January 02, 2010, 10:21:07 AM
Good news!

Fresh Blower seals are money well spent for the future, and the heavier 40Wt oil will bring up the oil pressure.

Keep us in the loop.

happy coaching!
buswarrior
Title: Re: MC-9 / 8V71 Woes
Post by: luvrbus on January 02, 2010, 10:33:02 AM
Mike, how did you determind you have bad blower seals also any oil pressure above 5 lbs is good on a hot idle they don't have much on idle and around 50 lbs at above 1700 rpm.
I see you live somewhere around Chaparral Rd according to your zip code I think 85252 is that area ? where do park a bus in that area.
I lived in 85253 zip and moved because the powers that be would not let me build a garage or canopy for my bus.
FWIW my daughter-in-law and her brothers own a chain of Mexican restaurants in the Phoenix area and my son owns 2 restaurants on Frank Loyd and Scottsdale Blvd I am in that area often so maybe at Quartzsite we can exchange numbers  




good luck
Title: Re: MC-9 / 8V71 Woes
Post by: BlueScarecrow on January 02, 2010, 07:19:17 PM
Hi Clifford... Thanks for writing.

I'm only theorizing, but it makes perfect sense.

Oil is seeping in through the blower seals (or from somewhere) into the blower and when the piston retracts and reveals the intake port the blower blows in fresh air along with some oil and it is combusted along with the fuel. This is the reason for the blue smoke. The reason that it does not run away, is probably that the amount is too small to support combustion.

When I gunned it the other day and it ran away for a few seconds, the amount probably reached the window of combustion and it took off! Since it was only a minute amount, the run-away lasted only a few seconds.

Then too, when the piston retracts and reveals the intake port, the blower blows in fresh air along with some oil in through the intake and right out the exhaust port. The oil lands on the superheated exhaust manifold... turns into white smoke... which travels out through the tailpipe. Remember it takes only a minute amount of oil to give a billowing white cloud.

When I did Special Effects in LA, we built a small cracker out of a 25 gallon drum. We filled the bottom with Johnson & Johnson Baby Oil just to cover the air manifold and we could make smoke all day without refilling the drum.

You are right about the zip. I use my brothers address as a base. He lives on 85th and Chaparral. I've been bouncing it around from location to location until I find a nice spot where it's not a bother to anyone and I have electricity to work on it. I have it parked at my apartment building right now. The owner is cool. Thought the Rolling Stones were in town.  ;)

What do you think of my theory?

Like to hear my theory on gravity?

Thanks again for writing!

If you like... send me an email and I'll send you my contact info.


Best regards,
Mike

N9EWS

Title: Re: MC-9 / 8V71 Woes
Post by: luvrbus on January 02, 2010, 07:40:21 PM
That is a good theory Mike but the only way to tell for sure it is the blower seals is to remove the air horn where the air cleaner connects to the blower start the engine and take a light and look at each end of the blower on the inside if they are leaking you will see the oil running down on the end plates.
Be careful those rotors are like a sausage grinder stay clear of those babies.




good luck
Title: Re: MC-9 / 8V71 Woes
Post by: BlueScarecrow on January 02, 2010, 08:27:39 PM
Yikes!!!

I will.

I think I'll take a look just before I change my oil.

I'll save that for one of my dirty day jobs. LOL

Keep your fingers crossed.

Thanks!
Title: Re: MC-9 / 8V71 Woes
Post by: cody on January 02, 2010, 08:43:09 PM
I think you'll find you've got a great bus, just got to get the rig up to spec a little. The guys here will guide you as needed, lots of very capable guys here that have seen almost any problem and the fix to it.
Title: Re: MC-9 / 8V71 Woes
Post by: buswarrior on January 02, 2010, 10:38:46 PM
oh phooey.

My suggestion is change the bleeping oil before you do any more theorizing.

If indeed you have 10Wxx whatever in there, it may be seeping past all manner of perfectly good seals that you will unwittingly think there is a problem.

Now, this "run away" event. We need more description of this event. There is a big difference between sticking throttle mechanisms on a coach that hasn't been run regularly, and an engine that is trying to run on lube oil.

Back to the first sentence. Change the oil, just for fun, find all the greasing points on the throttle rods and cranks from under the driver all the way to the back, confirm the emergency stop will function from the driver's seat, run it as prescribed earlier in the post, and see if everything else goes away.

happy coaching!
buswarrior
Title: Re: MC-9 / 8V71 Woes
Post by: JohnEd on January 03, 2010, 11:01:33 AM
While you have all this time on your hands you might want to put together a couple of "ramps".  You cannot escape needing those.  Take them to Quartz with you.  Grease the thing everywhere.  Do you need to unweight the fronts to grease the King Pins?

John
Title: Re: MC-9 / 8V71 Woes
Post by: BlueScarecrow on January 03, 2010, 08:56:00 PM
If I were going to grease the thing... I would take the weight off the front... yes!

I'm going to have a couple of ramps made out of oak and add a few oak 4x4's and maybe a square or two of 1" plywood.

Have you seen the chocks that go between the drive and the tag wheels? They go top and bottom and get pulled together for a nice tight fit so the wheels won't turn.

Ok... Ok... I'm going to change the oil this week. But I still think the blower seals are toast. ;)

Thanks for writing guys!


Mike
N9EWS

Ps. Who wants to hear a theory about gravity?
Title: Re: MC-9 / 8V71 Woes
Post by: JohnEd on January 03, 2010, 09:15:47 PM
Those are the best chocks ever.....I think.  I thought that should be intuitive but it doesn't seem so:  When you are pulling on the ramps put the chocks in line with the wheels at the end opposite of the chocks.  Place them the correct distance so they bump when you get to the top flat on the ramp.  Make sure the chocks won't slip and let you go too far.  Make those ramps with a slope off or down the "wrong side".  45 degrees or so....shirt ramp.  With a square cut off the ramp will tip up and you will impale the under carriage on the ramp.  Only makes the ramp 10 inches longer and not much heavier but pushing a ramp through a bay wall or battery box is well ?????  OAK!  You must have connections and a strong back.  I would if I could, though if only for bragging rights....Wanna see my solid OAK ramps?  Gonna cost ya a beer.

Send some of the oil and coolant off to be analyzed so you will have data for Clifford and Don whether they want it or not.  I keep saying that cause I am not sure I have been heard...not any way I can be insisting on you doing a single thing though....truly.

John
Title: Re: MC-9 / 8V71 Woes
Post by: BlueScarecrow on June 14, 2010, 01:57:07 PM
Dear All,

Thanks for all your help.

I have progressed a lot since my last post.

I have since changed my oil to the Shell Rotella T1 50 wt. and the bus is running great.

I’d really like to replace all of the injectors and see if I can get the mileage to come up a little.

I've completely removed most of the unused wiring and I re-wired the front and side marker lights. Oddly the side markers had no wiring.

I’ve also buttoned up a few air leaks and I’m working on the gearbox pulley that runs the squirrel cages. The two pieces of metal that connect to the heim joint actually fractured. It happened while I was driving and the motor just quit while I was making a left from 19th Ave to e/b Bethany Home Road. I like the fact that MCI has a built-in kill device to stop the motor before any damage can occur.

Beyond all this, I’m gutting the entire inside. The bathroom is gone along with the dump tank; and the bathroom floor (the floor from hell) is also removed. It was actually riveted to the body which was under neath the plywood flooring.

I want to take up the entire floor including the chair rails and replace it with painted marine plywood.
Has anyone gone this far and is there an easy way to accomplish this?

Thanks!
Title: Re: MC-9 / 8V71 Woes
Post by: RickB on June 14, 2010, 02:12:40 PM
I have four words that you don't want to hear said together in a sentence when you're working on dismantling the interior of your bus.

"Work hardened stainless steel"

If you get stainless hot by drilling or cutting it too quickly it will get tempered and you better have some expensive carbide bits and blades if that happens. I learned that the hard way working on my door. So drill and cut slow and use oil if possible when dealing with stainless

Don't ask me how I learned that little tidbit ;D ;D ;D

Rick
Title: Re: MC-9 / 8V71 Woes
Post by: JohnEd on June 14, 2010, 03:07:25 PM
Everything Rick said.   TWICE!  Use a grinding wheel where you can.  Buy good quality bits.

I have never been where you are.  I have sure seen a lot of others there.  That center section gets enough foul crap in it that it needs shop vacuumed and pressure sprayed when it is open and the bus is empty.  Sprinkle some Zink Sulfide/sulfate in there to kill of any future mildew/mold and some borax for other smells. 

But why would you want to replace the floor if it is solid?  Pull out that rubber flooring and you will destroy some of the sound proofing that the rubber contributes.  I should think that simply laying sheets of Polyisocy. in there at 1 inch min and then covering with 3/8s quality ply would be the hot ticket.  Less work, quieter, insulation.... wheres the down side? Not to discourage spray foam on the underside of the floor/ bay overhead.  Even if I had some soft spots I would try to replace sections and maybe do nothing if that spot was going to be under somthing that didn't need the support.

I have always thought I was missing something from my seat in the Peanut Gallery.  X thousands bus Knuts can't be wrong.

Got milk?

John
Title: Re: MC-9 / 8V71 Woes
Post by: Jriddle on June 14, 2010, 04:00:29 PM
Use a grinder with a cut off wheel to cut welds on the chair rail. Make sure you take stock in the company before you buy any cut off wheels because you will go through a lot of them. I drove a wedge in the rail to put pressure on the weld as I ground them. When I got close the rail would pop and I could move on to the next weld. I added a photo to explane why you should pull the floor.
Title: Re: MC-9 / 8V71 Woes
Post by: JohnEd on June 14, 2010, 05:13:34 PM
Is there no way you can get to that center section without puling the entire floor?  All I have ever seen is pics.

There has never been a question that that unholy mess had to be removed.  Not in my mind, at any rate.

John
Title: Re: MC-9 / 8V71 Woes
Post by: DaveG on June 14, 2010, 06:40:23 PM
Mike (N9EWS) I'm still waiting for your theory on gravity.

Dave G (KI6OWH)
Title: Re: MC-9 / 8V71 Woes
Post by: Jeremy Watson on July 21, 2014, 07:28:26 PM
Hello,
I recently purchased a 1971 MCI MC-7 with a rebuilt 8v71. I have been on the hunt for a great (and honest) mechanic in Phoenix to inspect and service it for me. While searching I came across this thread and noticed a couple members speaking highly of Michelangleo of Phoenix. I tried calling the number that was listed today and that number (602-340-001) is no longer associated with that business.

Can anyone recommend someone here in Phoenix?

Thank you!
Title: Re: MC-9 / 8V71 Woes
Post by: twostick on July 21, 2014, 09:01:41 PM
Hi Clifford... Thanks for writing.

I'm only theorizing, but it makes perfect sense.

Oil is seeping in through the blower seals (or from somewhere) into the blower and when the piston retracts and reveals the intake port the blower blows in fresh air along with some oil and it is combusted along with the fuel. This is the reason for the blue smoke. The reason that it does not run away, is probably that the amount is too small to support combustion.

When I gunned it the other day and it ran away for a few seconds, the amount probably reached the window of combustion and it took off! Since it was only a minute amount, the run-away lasted only a few seconds.

Then too, when the piston retracts and reveals the intake port, the blower blows in fresh air along with some oil in through the intake and right out the exhaust port. The oil lands on the superheated exhaust manifold... turns into white smoke... which travels out through the tailpipe. Remember it takes only a minute amount of oil to give a billowing white cloud.

When I did Special Effects in LA, we built a small cracker out of a 25 gallon drum. We filled the bottom with Johnson & Johnson Baby Oil just to cover the air manifold and we could make smoke all day without refilling the drum.

You are right about the zip. I use my brothers address as a base. He lives on 85th and Chaparral. I've been bouncing it around from location to location until I find a nice spot where it's not a bother to anyone and I have electricity to work on it. I have it parked at my apartment building right now. The owner is cool. Thought the Rolling Stones were in town.  ;)

What do you think of my theory?

Like to hear my theory on gravity?

Thanks again for writing!

If you like... send me an email and I'll send you my contact info.


Best regards,
Mike

N9EWS



I haven't read the entire thread but another reason a screamer will run away briefly is if it is dead idled for a prolonged period or driven at low speed, especially at low engine temps or if it has a few tired cylinders. What happens is the unburnt fuel that doesn't slobber out the exhaust collects in the air box and when enough of it collects, all it takes is for the engine to be revved up quick and it will inhale it, and away she goes.

I used to see it at trucking companies that would use an old beater with a 671 or 8v71 for a yard tractor and it would idle for days, never get out of second gear and the temp hovering about 130 deg.

The first guy that goosed it across the yard would get the ride of his life for a few seconds.

Kevin
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