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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: rv_safetyman on July 24, 2009, 06:56:25 PM
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Many of you have followed my story about my troubled Series 60 engine (http://www.busconversions.com/bbs/index.php?topic=12599.0)
In a thread about Sean Welsh's turbo problems (http://www.busconversions.com/bbs/index.php?topic=12676.0) he posted the text quoted below:
This morning, during my third and final warm-up/cool-down cycle, I plugged in the DDR to check on everything. Specifically, I checked injector response, which looked good on all eight cylinders, ranging from 1.07 to 1.17. I also ran the injector cut-out test on all cylinders at idle as well as 1,000 rpm, and all injectors elicited a response, with pulse width increasing by 0.2 to 0.4 for each cylinder.
For those unfamiliar, what this latter test does is to first report the amount of fuel being provided to the cylinders in the form of "pulse width" (PW), the amount of time the injectors are commanded to inject. Then it shuts off the injectors one at a time and reports the PW as each injector is off line. The idea here is that when a cylinder that was contributing real work gets turned off, the DDEC will have to increase the PW to supply more fuel to the rest of the cylinders to carry the load. If you turn off one injector, and there is no resulting change in PW, that means that that cylinder was not doing any work, which could mean a bad injector (or a number of other problems).
I am interpreting the results, being fairly consistent across all cylinders, as meaning that I still have all eight injector tips, and all the exhaust valves are intact. I'm not conversant enough with these sorts of tests to rule out any other problems (low compression, marginal injector, etc.), but I am fairly confident at this point that the turbine failure was not due to FOD originating in the engine.
That got me to thinking about using this test to check out a used engine to replace my dead Series 60. I have a Pro-Link Graphiq with the DDEC III/IV card and it looks like I can run the same test.
I would like to get comments about how good of an evaluation test that would be. Also, do any of you have advice about how to properly evaluate the test results?
Appreciate any advice.
Jim
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With the engine out and sitting on a skid one could perform a leakdown test to gauge the engines health. You will have to pull the injectors and rotate each cylinder to TDC.. You will quickly find out the condition of the rings, intake and exhaust valves and head gasket/liner.
If the engine is/was running you would be able to run the engine on a dyno and run all the mentioned tests and check for rated HP and torque.
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Jim, what good will a cut out test do except locate a bad injector it is not going tell anything other than the electronic part of the injector.
Cole is working on the info for you on the 2 engines and hopes to have it all by Monday then I will foward his email to you.
good luck
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Kevin and Clifford thank for the replies. What does it take to run a compression test? I assume that a special gage is inserted where the injector goes. Do you turn the engine over with the starter? Does engine temperature affect the reading? Is there a "goal" compression or are you just looking for differences? Have done the test a ton on times on a gas engine but not a diesel engine.
Next question, I changed from doing a compression test on gas engines to a leak down test. Is there a similar test for diesel engines? Can I use the same gauge with an adapter?
As you can guess, I am now paranoid about getting a decent engine. One of the engines I am looking at does not have an ECM, so there is no way to verify the reported very low mileage (wrecked bus that was in service less than four years).
Clifford, I really don't know what the cutout test would show. From Sean's comments, it sounds like it could be a good piece of information.
Another reason I ask, is that I was going to sell the Pro-Link as a part of gathering funds to buy an engine. I really did not want to do that, but sometimes you have no choice. So the big issue is whether I should keep it until after I check out the engine(s).
Jim
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Jim, the compression test for a 60s is a all day job removing each injector and re timing it will tell if you have bad valves, cracked head or bad compression rings and that is about it.
I would build me a stand to set the engine on and install my ECM on the engine you are looking at run it.The best way I think not a hard thing to do just watch giving it full throttle they will take off don't ask how I know that part. good luck
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Jim, there is a difference between a compression test and a leak down test. I don't place much value in a compression test. The leakdown test we typically start with 100 psi and pressurize the cylinder. The percentage of leakage from 100 psi will tell us the health of that hole. Rings, intake valves, and exhaust valves. You can also use a boroscope and look down each hole to view the cylinders/pistons for any damage or extreme wear.
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Jim, I would try to structure the purchase deal with some sort of warranty. 30 days or "X" amount.
This will give you the time to pull the pan and roll new bearings if you want. You can also pull the valve cover and check the camshaft for wear.
I should have explained and answered your question about the leakdown test. When we pressurize the cylinder we are finding out the mechanical health. In theory we should only have around 2 to 3% of air leaking out the rings, and valves. At 5 to 6% we have some wear. 10 to 15% we have to address looking at the valves or rings. The leakdown test will tell us which component is worn. This includes valve guides. You will want to listen to ANY air leakage coming out the exhaust/turbine housing>this will point to worn exhaust valves. Air/hissing out the intake will lead to a failed/bent intake valve. You will want to pull the oil drain plug>oil should be drained.. If you hear any air in the basement and the gauge is down you have a bad ring pack.
A compression test is a starting point, I don't even bother with them these days. It is the leakdown test and dyno test that really shows the condition of the engine. Being able to run the diagnostics and seeing the engine functions while under load with oil samples will usually give one all the data for a good engine.
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On the leak down test, I assume I can use my present setup and buy/make an adapter to fit in the injector hole. Are adapters available?
On a gas engine you have to be very careful to have the piston at top dead center, or the pressure will move the piston down the cylinder with a pretty off force. I assume that is also true with the Series 60.
I don't have a borescope. Almost bought one for a consulting case I was on, but it settled before I could justify the cost.
Jim
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Jim, what good will a cut out test do except locate a bad injector it is not going tell anything other than the electronic part of the injector.
That's not entirely true. The cut-out test will tell you if a cylinder is not contributing its fair share of the work for any reason at all, such as little or no compression. In fact, if the cut-out test reveals a bad cylinder, you can not assume it is an injector problem -- you must investigate further. The injector response time test would potentially reveal electronic injector problems.
-Sean
http://OurOdyssey.BlogSpot.com
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Jim;
I use a Snap On leakdown guage. I have various adapters, I have made a few >cutting/machining up a old injector, finishing up with a little tig welding.
Jim I have a later model DDEC IV S60, there are a few updates that I have to 225K. Feel free to get ahold of me to discuss a few things.
Kevin
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I can see a leakdown test with a gasoline engine, they are small and tightly built. I have my doubts though with the diesel. But I've never done one. Seems like an awfully lot of work. May just shoot alot of air into the pan with a cold engine. Last I knew the big diesel pistons don't get round until they are up to temperature.
I don't believe I would change out the mains or rods either unless there are a lot of miles on the engine. Everything costs more money. How did the bearings look on the 650,000 mile engine when it came apart? Should give an idea of where you are with another engine. The 60 series is not known for bearing failures.
The cutout test seems easy on the face of things, but it still takes some time and money to get an engine running in a stand. A dyno would be nice to, but that won't be cheap either. Put it in, do the cutout test and if it fails,take it back I guess. The labor to put it in probably isn't a lot different than trying to run it on a stand.
Any engine can have a failure, It's impossible to see the future. I was down at the DD Dealer yesterday and they have a lot of used up series 60's sitting out in the sun. Ease of repair and cost is one of the most important issues when you pick an engine that you will live with the rest of your life.
Personally, I would put the old one back togather myself at home. Then you would be ready for the issues that are to come and have the knowledge to deal with them. You would also be the resident expert on the bus boards! Your head was good, you can touch up your valves by hand with some lap compound if you want and buy a couple new or used valves if needed, and if you find a guide or two that are a little sloppy, you can knock out the old one and put in a replacement.
The camshaft is a little complicated, but if you send the block out to have the 2 counterbores cleaned up you can pay to have the cam bearings changed out, or you can have the shop send you a mechanic to do the counterbores at your shop/home and only do the cam bearings if they need it. They could also install the liners and you could pretty much handle it from there. I think you can just change out the bad cam follower and leave the rest if they are OK.
I might advertise for a part time DD mechanic in your area, people are out of work and you may find someone to sort your good parts from the bad and put it back togather for you pretty reasonable, then you would know what you had and know alot about it for future reference. The 60 is a lot easier to repair than a 2 stroke.
I'd probably just take a good look at the camshaft on the used engine, and take my chances. Who ever is selling should have already checked the cam and main/rod bearings though, most all salvage yards do. I have dealt with American Truck Salvage in Phoenix, they usually inspect the internals on all their engines. They have an engine shop, a tranny shop and a rear gear shop on the premises.
They have a 12.7 for $8,000 that has 170,000 miles on it and if they have not looked at it I believe they would open it up for you on their dime and show it to you, no charge if you told them you would take it if it looked good.
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Sorry Sean it will locate a missing cylinder but won't give Jim the info he is looking for Zero's method is the only way to determed that by pulling the injector and testing.
Jim I also have the test equipment if you need it you are welcome to it Mac has a set that cost less than Snap On and I have saw guys take a old injector body and make their own.
That test is a luxury us 2 stroke owners don't have we have a compression only at 900 rpm removing 1 injector at a time then replace it time it go to the next one.
If you want to check on the one at American Truck I'll be glad to drive to Phoenix and do some checking they are good people they may even run for you on a stand they did for me on a 8v92 good luck Jim
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NJT, I have pulled the leakdown on a fair number or Cat's 3304, 3306, 3406 B,C D398, D399.. I have NOT done it on my own Series 60. But that is the only method to gauge the health of a engine without running it on the dyno. An engine running on a test stand without any load will just prove that it can run and idle.
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Kevin,
I agree, that is a good test procedure. The problem I see, is weather or not it's realistic for Jim. To put 2 or 3 engines on a stand and pull the heads/injectors down and put them back togather ain't going to be cheap. We got a guy here that is thinking about selling his tools just to purchase another engine. I'm with you, we would certainly like to see him get a good one, but can he afford to spend $1000 or more to inspect each of the available engines?
Some people may prefer to sell to someone else rather than have what they believe is a good engine pulled apart and possibly not put togather properly again. Is Jim going to replace the oil at his cost? He has to spin them over and coat the cylinder walls to get a good reading. Can Jim afford to haul them down to Detriot Diesel and pay a hundred an hour? If there is some carbon stuck under a valve, you would reject a good engine, and thats not unusual. Probably better to pay for a dyno.
I don't think a leak down will spot a wearing cam lobe though, or worn rods or mains. Mostly I think valves and ring or piston damage.
If you offered to jump on a plane for free and the seller agreed you could really help out on this one. If Jim was qualified, he would be repairing his old engine.
I think he is in a position of having to trust the seller and believe the information furnished about each possible engine. Next comes the sellers reputation. If they deal constantly in these engines I would expect a much better outcome if there were issues. They also have a reputation to maintain or in todays world they won't sell alot of engines if the word were to get out that they ran alot of scams. A big outfit like American could afford to hand Jim another engine if they had/wanted to, can the other sellers?
Thats why I suggested American. I also was struck by the picture of the engine they have for sale. The block was unpainted, making me think that it has been hot tanked and likely had machine work, more so than a supposed rebuild that is still wearing the factory paint. I'd still try to find out who did the rebuild and verify DD or aftermarket rebuild kit, but I would chose a rebuilt that has seen a hot tank before one that has not, even though it probably doesn't guarantee anything. Might want to ask about the crank to since it has been out of the unit rebuilt. Turning it won't hurt it any though, but I would like a simple .010 cleanup or nothing under ideal circumstances. Might shy away from a .030 crank, but the engines that are inframe rebuilt have certianly not had the crank clean up turned or crack checked at all, and leak testing won't get you close to any of these issues.
Larry
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Larry, in the end it is Jim's choice. The economy is in the toilet and these truck salvage companies have to be flexible. They can't jsut say>> it's only got 200K on the clock and it will be fine.. It seems like yesterday that Jim was writing about his install. The pain to go thru this twice isn't fun. I would spend and negotiate with the seller to do a leakdown test. Carbon between the valve seat will and should be dislodged by rotating the engine a few degrees and re-pressurizing the cylinder. And BTW, I have never had carbon under a valve/seat and got a mis-reading using this method. Anotherwords if you have 5 cylinders reading between 4 and 6% leakdown and then you hit one with 24%.. You have to question what is wrong. Rock the engine off TDC if the air is coming out the exhaust valve. Put the air back to the cylinder > you will dislodge the carbon.
Most of these wrecking yard engines are exposed and can be serviced. From my very first post, a leakdown test and bearing inspection will a oil sample will quickly slant things in your favor and give you some piece of mind.
These test will cost you some monies. Inventory is high right now. There should be a salvage company that is willing to work to a higher standard if the customer is wanting to pay some monies. They don't want to be selling junk.
In the end, paying a little now vs having a engine fail down the road just doesn't make sense. The other option is to pay more monies for a low mile engine. Larry I do not disagree with all of your points, (exception> I wouldn't rebuild his engine> unless he bought a recon engine block machined back to std/std) Regardless we feel Jim's pain..
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Man, every time I read about Series 60 engines I start to worry about my engine. I do everything to treat it right, but who knows about the last owner? My coach had so many issues at the start (since fixed) that I doubt they paid much attention to the engine. It would probably be game over for me right now if I needed a replacement Series 60 engine.
I think Jim did most of the hard work when he installed his Series 60 so swapping in another one should be a piece of cake compared to the initial install. He already has the motor mounts and all the other modifications made.
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Hey Belfert, if you or anyone here blows a S60 and wants to sell their coach, let me know! I have a S60 that needs a home...unfortunately it is condition unknown, as the truck I got it in was in a fire and I was not privy to the overall condition before the fire...only assume it to be a runner...as a side note, I do have a nice low mile Cat C-12 with jakes....have all maintenance records since new...too bad my driver totaled the truck last month, now I gotta find something to do with the S60 and the C-12!
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Jim,
I still would rebuild your engine, were it me. I just would not give anyone $15,000 for a rebuild, I would do it myself and maybe hire a little help here and there.
You have alot of good parts. Your crank is good, your block is basically good, (needs 2 counterbores cut at most), may pass with shims only, if one of those two dropped holes were not the bad gasket hole. No need to pull crank and strip block for a line bore, that was never a problem. Your head is good, turbo good, etc.
I think you can get the 2 counterbores cut for a couple hundred. You need a inframe kit, aftermarket is $1995 from ardiesel.com. My local diesel machine shop regrinds camshafts for under $200 and you should be able to get a comparable price in your area, (and yes, it is a common practice). Don't know what you will pay for the cam follower, but probably less than $100. Head bolts are spendy, but you probably won't find wear on all of them, lets say $125 for head bolts. Don't know if its cheaper to put your 2 questionable injectors on a stand or get rebuilt @$200 each. Some injector shop should be able to look yours over for less than $400.
Still thats all your machine work and parts for under $2900.
The gaskets all come with the inframe kit.
What did I miss? If you can find some experienced help with a liner tool, @ $20 hr, or so, 50 hours should have it back in the coach. Is that within your budget? You could spend a little more and get a genuine DD rebuild kit, guess I'd ask who makes the $1995 deal, I'd probably go for Sealed Power though.
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Wow, not too sure where to begin with my comments. We have had terrible Internet for the last few days, plus we are dog tired from the show and some local activities. Still on the road and will not be home for 3 or 4 days.
Brian, in this thread and one of the others, you have expressed some concern about your engine. I am pretty sure that my engine had some poor maintenance. Probably had car type antifreeze, lots of idle time and who know how often the oil was changed. I am told that these engines are really robust. I can't recall how many miles your engine has one it, but if it is under 500K, I would not worry. If it is over 500K, I would think about having someone roll in the rod and main bearings. That would tell you a lot about the engine and get rid of one worry item. It is a pretty easy job for someone that knows what they are doing.
When I bought the engine, it had something like 670K (can't find my printout and data was lost when we switched ECMs). I am finding out that at about 700K SOME Series 60s start having problems. One site that someone sent me to had perhaps 25 Series 60s and almost all in the 700K plus range had problems.
NJT, my engine has a ton of issues. The head has some "wear" where the combustion got by the liner/gasket. The valves are pretty recessed. Two injectors are shot. The bull gear is due to be replaced. Then, of course, the cam and follower are bad.
I have done several gas engine rebuilds, but I would just not feel comfortable running an engine that I rebuilt while "in training". I don't know of any mechanic that I could call to help me. I have one contact and I might explore that avenue, but the probability of rebuilding it is slim.
Back to maintenance. As someone pointed out, you can learn a lot for the bearings. I had new bearings rolled in, but they tossed the old ones before I could look at them. I did drop one rod cap to make sure they did the R&R.
Probably missed a comment or two.
I am leaning towards a used engine that I can check the background on (thanks to Clifford and friend!!!!!).
Jim
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Brian, in this thread and one of the others, you have expressed some concern about your engine. I am pretty sure that my engine had some poor maintenance. Probably had car type antifreeze, lots of idle time and who know how often the oil was changed. I am told that these engines are really robust. I can't recall how many miles your engine has one it, but if it is under 500K, I would not worry. If it is over 500K, I would think about having
I believe my engine has somewhere between 300,000 and 400,000 miles on it. The DDEC appears to have been replaced shortly before I bought the bus as it had something like 49 hours on it when purchased. I think the 300,000 number came from the odometer, but who knows if it was original as the speedo was reading way high. The overall condition of the coach other than maintenace items plus the number of years sitting made me believe the odometer. The engine had been run for some time with a pretty blocked up air intake that I rectified before I even got the got coach home.
My friend had a semi tractor with Series 60 with over 1 million miles and the engine had never been touched so I am not terribly worried about my engine.
What is car antifreeze versus diesel antifreeze? I have been running the plain old green stuff. My first replacement coolant was from a Freightliner dealer so I suspect it was the right stuff. My round of coolant was the plain green stuff from a auto parts place down the block from home.
I hope your search for a replacement engine goes well.
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Brian, probably someone else will give you a better answer on the antifreeze, but here is my take on all of the reading that I have done. Diesel antifreeze is a special low silicate version of ethylene glycol. It has additives that are called SCA, which must be kept at a minimum level. All of this is to prevent cavitation of the liners.
The OEMs and "experts" really hammer home the need to have the proper antifreeze in the engine. You probably saw the results of cavitation on my liners at: http://rvsafetysystems.com/Engine_problems.htm. At least one person said that the amount I have is "typical". I question that, as the pitting was almost half way through the liner.
I think there has been quite a bit written on this board about the subject.
You don't use your bus a heck of a lot, but I would be tempted to change the antifreeze.
Update: I just started a thread on the subject of antifreeze: http://www.busconversions.com/bbs/index.php?topic=12775.0
Jim
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I have been adding SCA to my coolant as required. Precharged coolant costs more than just adding SCA.
The bus garage was supposed to test my coolant as it was on my list, but I don't think it was on the invoice. I'll have to call them today.
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JIM
Have you looked at EBAY today ???
http://cgi.ebay.com/ebaymotors/DETROIT-DIESEL-SERIES-60-USED-DIESEL-ENGINE_W0QQitemZ370240870482QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item5634135852&_trksid=p4506.c0.m245 (http://cgi.ebay.com/ebaymotors/DETROIT-DIESEL-SERIES-60-USED-DIESEL-ENGINE_W0QQitemZ370240870482QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item5634135852&_trksid=p4506.c0.m245)
http://cgi.ebay.com/ebaymotors/3-4-Detroit-Diesel-Reliablit-Series-60-Eng-Freightliner_W0QQitemZ160353650759QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item2555d28847&_trksid=p4506.c0.m245 (http://cgi.ebay.com/ebaymotors/3-4-Detroit-Diesel-Reliablit-Series-60-Eng-Freightliner_W0QQitemZ160353650759QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item2555d28847&_trksid=p4506.c0.m245)
??????? - what do ya think ??
Just trying to help
Pete RTS/Daytona