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Author Topic: Slow going  (Read 4738 times)

Offline Purplewillie

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Slow going
« on: August 13, 2013, 12:03:03 PM »
Back from a weekend run to Nancy Green Park. About 250 miles there and home, but like most of the BC interior lots of steep climbs.
Bus runs great, but she is one slow turtle on the hills. I have not checked what injectors are in my 871,but I would think it must be still around the stock 250ish hp. On 8% grades we top the hills at 20mph , but no smoke at all. 70 mph on the flat, but 30,000 lbs and no power make for a slow tour.
140,000 miles on this motor ,no leaks,
Should I look into bigger injectors?
Timing ? Or just keep turtling along?
Mark
Mark & Char
1976 P8M4905a 8v71 v730
British Columbia Canada

Offline bevans6

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Re: Slow going
« Reply #1 on: August 13, 2013, 12:05:42 PM »
I would pull a valve cover and see what you have, as a start.  Then you can make an educated decision.

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Spicer 8844 4 speed Zen meditation device
Tatamagouche, Nova Scotia

Offline Purplewillie

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Re: Slow going
« Reply #2 on: August 13, 2013, 01:03:43 PM »
N65
Mark & Char
1976 P8M4905a 8v71 v730
British Columbia Canada

Offline Purplewillie

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Re: Slow going
« Reply #3 on: August 13, 2013, 01:04:23 PM »
Mark & Char
1976 P8M4905a 8v71 v730
British Columbia Canada

Offline Taibob

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Re: Slow going
« Reply #4 on: August 13, 2013, 01:18:17 PM »
 
Mark.

All your symtoms are of a good motor.
Do yourself a big favour and ++JUST LEAVE IT ALONE++.
Its not broke, so don't break it looking for more.

I have the same setup and run the same or more hills from here to Alberta. Just returned from SanFrancisco and the climb from sea level to 7332 ft at Reno, and the 10 mile climb out of Butte Montana and then the Salmo Creston,Paulson,Christina Lake,Elholt,Rock Creek, and finally the Antichrist at Osoyoos. Hope-Princeton has the climb at Copper Mountain,Sunday Summit and Alison Pass. Just a few.

It took me a while to get off the power kick as I thought 28 mph was too slow also.  Guess what , I just pull over for traffic, when convenient and have adopted the attitude that I paid for the spot on the road that I am using. It also gives me the time to thank my old bus [Girlfriend] for getting me to where I am and back again.

The secret is to gear down, run on the govenor,and watch the temps.

Love your bus and it shall serve you well.
Oh, and smell the flowers along the way.

Regards  Bob
84 mci 9  8v71n N70 Jakes 740 auto 2 Slides    BC/AB Canada

Offline treeplanter

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Re: Slow going
« Reply #5 on: August 13, 2013, 01:28:24 PM »
My bus also creeps up the hills i have the same engine but it's hooked up to a allison VS2-8, 70 to 75 on the flats,looking into propane injection for hill climbing. the steepest grade was our road to home,shifted to first and she made at about 20 mph or less,we have the steepest grade in the county,dirt road, the dust we kicked up was blinding.
Timothy

Offline Purplewillie

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Re: Slow going
« Reply #6 on: August 13, 2013, 01:28:56 PM »
Bob, that is kinda what I was thinking, but I was hoping for 25 to 28 on the hills. I have been shifting my v730 manually , but I still end up unlocked and in 1st at the top. 20 just seemed a tad underpowered .
Mark & Char
1976 P8M4905a 8v71 v730
British Columbia Canada

Offline boxcarOkie

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Re: Slow going
« Reply #7 on: August 13, 2013, 01:33:44 PM »
RULE OF THUMB:  "If you are driving a bus ... You should not be in a hurry."

Nice picture by the way.

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Offline LowTide

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Re: Slow going
« Reply #8 on: August 13, 2013, 01:34:58 PM »
Wish I could help, but I have to say, the scenery is to die for......hopefully one of these days we will be enjoying such beauty ;)
Mike and Lori
Sunny Phoenix Arizona
"1973 MCI MC-7 Challenger"
"Just Misbehavein' "


"A nation of sheep helps breed a government of wolves"

Offline Purplewillie

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Re: Slow going
« Reply #9 on: August 13, 2013, 01:35:28 PM »
Brand new autometer gauges and senders
180 water
Trans climbs to 220/225 on the long hills
Mark
Mark & Char
1976 P8M4905a 8v71 v730
British Columbia Canada

Offline Purplewillie

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Re: Slow going
« Reply #10 on: August 13, 2013, 01:51:53 PM »
Mike, it is beautiful here and we would love to share it.
Don, Thanks  ,
I am no longer in a hurry and my wife loves it.
Spent the first 50 yrs of my life ripping up these roads on bikes and in cars
I recently sold my cbr 1000 , I noticed when I turned 50 my reaction times had slowed significantly. Still have the corvette , just in case I'm feeling too old
This 8v71 runs so nice and its so clean, I'm going to have to leave it as is.
Mark
Mark & Char
1976 P8M4905a 8v71 v730
British Columbia Canada

Offline bevans6

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Re: Slow going
« Reply #11 on: August 13, 2013, 02:20:21 PM »
You could check the timing to see if it's set right, but as a rule of thumb only if you have N65's and they are timed right for your cam gear (advanced or standard) you about have what a natural 8V-71 is going to get.   You can probably fuss around a bit and get a little more, but you won't get 5 mph on a hill more.  That would take a fresh engine and a turbo, and a lot more gears in the tranny...

I second the beautiful picture and great looking bus!

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Spicer 8844 4 speed Zen meditation device
Tatamagouche, Nova Scotia

Offline wg4t50

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Re: Slow going
« Reply #12 on: August 13, 2013, 03:03:33 PM »
Assuming the 4104 could navigate those mountains, I would guess the4106 would be much more lively ?
I would have the timing, rack and valve clearance checked by one who understands what they are doing.  Not everyone with a wrench has a clue.

My guess, it is not getting full rack stroke on all 8 injectors atleast, wouldlike to also check the timing pin setting, and of course the valve clearence. Maybe not going full RPM too ?
« Last Edit: August 13, 2013, 06:44:20 PM by wg4t50 »
MCI7 20+ Yrs
Foretravel w/ISM500
WG4T CW for ever.
Central Virginia

Offline Stormcloud

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Re: Slow going
« Reply #13 on: August 13, 2013, 03:34:24 PM »
.....or.......you could move east to Manitoba. They say there is one hill in Saskatchewan, but I haven't seen it yet.....I'm thinking it's a mirage.

My MC7 with N65 injectors and 8V71 with auto is just perfect for here, and it ain't too bad going to Arizona and back pulling a 5500lb toad.

Ditto on the nice photo!
Mark Morgan  
1972 MCI-7 'Papabus'
8v71N MT654 Automatic
 Brandon, Manitoba, Canada in summer
 somewhere around Yuma, Arizona in winter

Offline Ed Hackenbruch

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Re: Slow going
« Reply #14 on: August 13, 2013, 03:52:51 PM »
If i remember right i have N60 injectors in my 8v71N and have been down to 20 mph or even less. I just throw on the 4 ways and get in the right lane if there is one, or pull over to the side of the road every now and then if i can and let people by me.....in fact i just did that today and i wasn't even down as low as 20 mph.
1968 MCI 5A with 8V71 and Allison MT644 transmission.  Western USA