Swap or repower 6v/8v

[Craig Bowen]

Hello, I am new to the site and have a few questions.  I purchased a 85 eagle last Dec the bus has performed well.  It has a 6v92t with a 740 Allison trans.  It is getting over the hills ok..., but I would like to pull a trailer.  It recently developed a front cover oil leak that I need to address.  The motor is a reman from 2001 I have not pulled the valve covers to check injector size so I am not sure what I am dealing with for horse power as of yet. 
            A. Can you get more power out of the 6v without over heating?
            B. Any pros or cons to swapping it for an 8v92 Is it a relatively smooth swap?
            C. Is there many problems with the 740 trans should I pull it and have it freshened?
Thanks for your help
Craig, Westminster MD.

[white-eagle]

Have you got a model 10?  i've got an 8v92 and a model 15 and it's tight.  not a lot of room to work on anything.

try posting this on the eagle's board, or on the facebook version of the eagles board.  there are some really knowledgeable people on that board, about Eagles.

[Utahclaimjumper]

 If it ain't broke, don't fix it,,Its all about gearing.. Look at all the 18 wheelers pulling massive loads,, they have enough gears to keep the engine spinning and purring,, just don't get in a hurry,, this way you will retain the mileage that the 6V92 is known for.>>>Dan

[Craig Bowen]

Thanks for the input.  It is a model 10, where is the eagle board to post on?
Thanks

[Low Class]

Craig,
check your mail.

[Van]

http://www.eaglesinternational.net/
Facebook- https://www.facebook.com/groups/106447321553/

[TomC]

The 8V-92TA is one of the hardest engines to cool (only the 12V-71 was worse). I would keep the 6V-92TA-it's reliable and with proper maintenance it will give you many years of faithful service. Granted you might be a bit slow on some grades, but how much of a hurry are you in? There are many commercial buses with 6V-92's still running.

If you want maximum performance, then the 90 injectors are what you want. They will give 335hp and 930lb/ft torque. If you have a bypass blower, it will be rated at 350hp and 1,000lb/ft torque. You can get a bit better fuel mileage with 85 injectors, but will be slower up the hills.

I had a '79 GMC Astro (cabover) with 6V-92TA at 335hp with 7spd Spicer.  Was fun to drive, just sit back and enjoy the scenery when climbing a hill. Good Luck, TomC

[RJ]

Craig -

I agree with Dan - If it ain't broke, don't fix it!

Thousands of coaches pounded the pavement for years with the powertrain you've got, and did so reliably.  Vast majority of coach 6V92TAs were set up for 275 hp, bumping yours to 335/350 will not harm it, just pay closer attention to the temp gauge.

The 740 Allison is virtually bullet-proof, just do the routine PM on it like any other piece of mechanical equipment.

When you start pulling Rocky Top, downshift manually, don't let the Allison shift by itself or you'll experience overheating problems.  Read the following for some tips near the end of the article:

http://busnut.com/forum/index.php?action=articles;sa=view;article=41

How heavy is your trailer?  Tongue loads can be an issue if it's a heavy one - not static loads, it's the dynamic loads induced while on the road, since most buses were never designed to tow a trailer.  Search the archives for lots of info on this.  (Eagles are better than some others in this regard, btw.)

And above all, remember you're driving a BUS, not a BMW!  Treat it accordingly, and it will give you years of enjoyable service.  Trying to drive it like a BMW will give you months of frustration and headaches.

FWIW & HTH. . .

[wg4t50]

Quick note, for some fun, install the 9200 injectors, they will pick it up a few notches, I ran and loved them in the 8V-92. A friend ran the 150 injectors, way way tooo much, smoke some too, when not up to full turbo boost, would clean up at a goodly boost psi. That setup was in a Scenic with the RTO910, 3.73 & 11R X 22.5 & 2600 rpm, oh yes.
Boyz & Toyz and never grew up, I am somewhat saner than him, of course.
Dave M