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Author Topic: Well here's the plan for the 8v92  (Read 1258 times)
RickB
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81 MCI 9 smooth side 8V71 Allison 754




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« on: February 08, 2010, 04:32:30 PM »

Good Evening from a snowy Minnesota evening,

After alot of thought and some great input from friends I have given the go ahead to my mechanic to rebuild the turbo, test the injectors and finish the tune up. Then the plan is to cover it up and spend some time trying to find all the parts I need to do the repower and the list is extensive to say the least.

Finally I am going to trust the big "3" (Clifford, Don and my mechanic Curt) and install the beast and run it until
it cleans itself out and quits spittin' up it's dinner. (airbox drains LOL Grin) There is a combined belief among the 3 of them that says she'll quit smoking and leaking. After my conversation with Van (thanks buddy) I'm certain I'm not the first guy to start an engine that hasn't been run in a while and encountered some smoke and leaks and that some here among us have seen much worse than mine clear up and run great.

Still haven't made the decision of making the changeover before or after our Yellowstone trip the last two weeks of June. It depends on how much trouble I have finding parts for a reasonable price. Thanks to some suggestions from folks here I am going to hold on to my 8v71 for a while just as a backup plan.

Thanks to all of you that talked me down from the ledge I appreciate it.

Man if I had trouble flooring my 8V71 what am I gonna do when something actually happens when I hammer it??

I will keep you all informed as to the results of the tuneup.

Rick
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Van
Billy Van Hagen
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89' Silver Eagle 15/40 6V92MUI Boulder City,NV




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« Reply #1 on: February 08, 2010, 04:57:21 PM »

 Good luck Rick Smiley, enjoy the family trip and the 892 will still be there, wagging it's tail waiting for you LOL!
  Now so far as how to react when you get that engine in...   Just scream WOOO! HOOOO! WHAT A RIDE! Grin Grin Grin Then when that has passed, get back to checkin the gauges. All the best
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akroyaleagle
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« Reply #2 on: February 09, 2010, 01:37:24 PM »

I changed my 8V71N to a 8V92TA(500HP). Mine went into my 05 Eagle.

Here is some information for you to consider:

With the 92 your shift points should be:

1-2 1900-2050 rpm
Lockup - 2000
2-3 2025-2100
3-4 2000-2100

The HT740 is part # 6884538. You should recalibrate the valve body to part # 23040804 Specs.

The 495 converter is 2.391 ratio, 496 is 1.78 ratio. There are a LOT of over the road trucks running around at 80,000 pounds with the 495 converter.

Upon the advice of a lot of experienced folks I know I did NOT change the converter. Mine works great but I do not hammer it from a stop. I use the power
to climb.

Here are some of the parts you will need:

8928605 low profile blower housing (could be 8922167)
5104464 low mount engine bell housing from a Ford Truck with a 6v92 or 8v92
9402015 crankbolts (12)
23045507 adapter hub, flexplate to crank
5143106 Y manifold
8922502 front turbo brackets
E8927027 Garret Turbo A/R .81
5101174 double cooler w/wp pipe
A BIGGER RADIATOR!!!!!!

Be sure to plug the 2 holes (5/8")between the blower and govenor housing!

Drill the lube orifice for the front blower bearing if you go with the optional turbo mount.

I do not know the SN of your engine. I assume it is a Silver. It should probably have 9G90 injectors.

For what its worth, if you allow someone to patch this engine in, you will probably end up with a lot of money in it and never be happy with it.

I would pull the transmission, have it recalibrated, dyno it and use the same torque converter. Install a larger radiator.


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Joe Laird
'78 Eagle
Huron, South Dakota
RickB
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81 MCI 9 smooth side 8V71 Allison 754




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« Reply #3 on: February 09, 2010, 02:05:54 PM »

Wow Joe... what a great source for me right now. Thank you. Hey do you have or can I find the same transmission specs for a 754 Allison? Shift points etc...?

I have been wondering whether my torque converter is rated for the extra power but it's hard to tell before we pull the motor. I am rebuilding the 754 during the repower as well with a friend who has done may Allison's.

low profile blower housing??? I am assuming you are talking about the intake manifold for the turbo thats attached to the top of the blower correct? I was wondering if I would have enough clearance for the turbo.

I am hoping to find an MCI 9 that has a blown 8V92 in it (spun bearing or cracked block would be good to find ... really expensive to fix but leaves everything external intact) I have the bigger radiators, I think one of the difficult finds is going to be the two bolt front engine mount and the 8v92 cradle. Then I have to find all the parts that you pointed out for reasonable prices. I got quoted $500 for two used squirrel cage shrouds by a guy that alot of us get our parts from. that is alot of money for a couple housings. I eventually found a whole blower gearbox assembly with shrouds for $150 used which fit my pocketbook a whole lot better. I will need a shallower oil pan as well.

Kinda make me nervous when I start looking around and getting prices for this stuff. I know it's gonna be expensive.

Thanks again Joe,

rick
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luvrbus
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« Reply #4 on: February 09, 2010, 02:26:26 PM »

Rick,in the MCI a top mounted turbo will fit they have more head room in the engine compartment than a Eagle you need a shoe horn for a Eagle or raise the floor.
Send me a list I am going to ALB NM next week and will pick the pan up for you with other parts I think will work for you he believes he has a bell housing from 6v92 out of a MCI.
Fwiw most 754 have a good torque converter that will stand the extra torque because of the low gear.

good luck
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akroyaleagle
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« Reply #5 on: February 09, 2010, 02:38:09 PM »

I got the specs from Allison. I'm sure they have them for the 754. If not give me a call at 6055540145 and I will get them for you. If your friend has done a lot of Allisons he should know.

The low profile blower housing sits on top of the blower. It is to get the blower horn up high enough to clear the high valve covers used with Jakes. I made mine out of a solid block of aluminum when I installed Jakes on the 8V71N before the repower, and just reused it with the 92. I just came across the housing number later as I got smarter.

The turbo should probably be relocated to the front of the engine.

You will need a much larger air intake filter also. Get one exceeding 1600cfm. After buying many used parts and crawling through a LOT of truck junkyards I gave up and went to the Donaldson Warehouse, spoke with the rep and they put together the complete intake system for me. It cost less than I had already spent trying to make something fit. As I said, I have learned a lot since those days. I stopped some years ago trying to find things to patch something together with. It is far better and a much neater installation to get the right components and save yourself the aggravation and expense of trying to adapt junk.

I'm not familiar enough with the Prevost to know how much room you have between the top of the blower horn and the floor. You can measure it. Be sure to consider the additional height that would be needed for the Jake covers and blower housing.

I don't know where you are located but there are some bus salvage yards in Canada that would have the external parts for the Prevost necessary to install the 8v92TA.

The 8V92T is still a popular engine with truckers in Western Canada.

You could also pickup some of the trucker magazines that are free in many truck stops. They usually have a lot of sources for parts.
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Joe Laird
'78 Eagle
Huron, South Dakota
akroyaleagle
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« Reply #6 on: February 09, 2010, 02:43:45 PM »

It appears that I am a bit confused as to what bus you have. I didn't look at the little photo close enough. In rereading the posts, some of which were posted while I was typing I see you are located in MN. I am in eastern SD.

If it is a MCI, those specific parts parts are probably available here in the US as well as Canada. There are many MCI owners on this board that probably know where bettter than I.

All the other info remains the same.

You are on the right track with Clifford and Don. I will now try to exit as humbly as possible.
« Last Edit: February 09, 2010, 02:49:39 PM by akroyaleagle » Logged

Joe Laird
'78 Eagle
Huron, South Dakota
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