8V92 TA Engine Questions

[TomMagarian]

Good day to all,

I am the proud new oner of a 1986 MCI 102A3, with a 8V92 TA & 5 speed Allison Transmission, with a Jake Brake, it was a new bus converted by Custom Coach of Ohio. We use the motor home to get from Chicago, to Colorado to go Skiing.

I have owned the bus for about a year, and made 3 trips to Colorado from Chicago, and noticed that it consumes about 8 quarts of oil in about 2,300 miles. I use Delvac 1640 40W oil. Also when warm, the engine has very low oil perssure, about 5#, when running at 1,200 RPM or above it is about 55-60#. My fuel milage when averageing 67 to 70 MPH is 5.5 MPG.

Are these comditions normal for a coach of this vintage? The coach weighs about 38,000 lbs. It runs well, and will go over 85MPH, but the fuel economy drops to under 4 MPG if you push it fast, so I have learned to drive it at 67 MPH, or about 2,150 RPM. engine speed which equals 67 68 MPH & 5.5 MPG

Looking for comments on this type of coach.

Thanking all in advance.

Tom

[hermanmullins]

Tom,

Welcome to the Forum.

Help me understand. You said that you have made three trips from Chicago to Colorado. I have been to both and my second trip would have been one way. :lol: Just Kidding.

Brett Wolfe will see this and give you some great advise. Listen to what he says, he knows what he is talking about.

[TomMagarian]

Thank you for responding, any input would be appreciated.

Tom

[wolfe10]

Waiting for those with more Detroit Diesel two stroke experience.

Your MPG at the speeds you drive is about average.

Go to page 4 of this Caterpillar Corp document to see the HP required to run at different speeds-- the same physics applies irrespective of engine: http://www.catrvclub.org/PDF_Docs/Understanding_Perf.pdf

Brett

[TomMagarian]

Thanks Brett,

This article is well written, and spot on. I was under no disillusionment about fuel economy. I could see the fuel vs speed requirements from my own experience.

I am more interested in understanding what I can expect relative to engine life.

Questions like what kind of serviceable mileage life, can one expect out of the 8V92 TA mechanical motor?

Also what is reasonable oil consumption, VS leakage for this beast?

Real world experience on engine cooling while pulling grades at 8o degrees Fahrenheit. ect.

[sgureasko]

Use Delvac 100 40wt. It has low ash, which that engine requires. Also, the faster you go, the more oil it burns (just the nature of the beast). Your fuel mileage is average.

The Delvac is available through O'Reillys, and can be ordered by asking for 100-40. Don't know of a store that stocks it, of course, those engines are dinosaurs.

Be sure and keep up with your cooling system, that is the weak link with that engine. Also, don't idle very long (use a fast idle, if you do) as you know you only have 5 psi, which is also normal.

I have learned (actually, forced myself) to drive 63-65 MPH, and have cut my oil consumption way down, and increased my fuel mileage some. It isn't much but I'm almost 15,000lbs. heavier.

My redline is 2150, so I try to keep it a little lower so I have some reserve for passing, etc.

Mine is a '90 Wanderlodge with almost 220,000 miles on it.

[sgureasko]

Tom,

Since no one else has commented on your bus and engine, let me throw some sites out to you. There is The Bus Nuts, Detroit Diesel Two Stroker, and of couse WanderlodgeOwnersGroup.

By going on any or all of these sites you will get more information, plus will be to answer any question you have on anything you have.