Mileage expectancy 'til rebuild

[Hi yo silver]

This question has been eating at me for some time now, and I haven't been sure how to present the question, so I'll just jump in.  After having looked at buses for a few years, I keep seeing ads claiming recent engine rebuilds even though the total coach miles were something under 200k or so.  Am I to deduct that I can expect to shell out $10k for a rebuild at somewhere around 200k to 250k miles?   Another owner mentioned "lower end" bearing replacement.  What's typical?  Or, is there a typical expectation?
Thanks,
Dennis

[Stan]

When a commercial operator retires a bus, there is probably enough miles left in the engine to last a conversion owner a lifetime.

Just how many miles do you plan on driving that you are worried about engine rebuilds every 250 k miles? If it really is a concern, buy a bus with series 60 and do a rebuild and then it should last for one million miles if you you are driving it many miles every year.

[Ncbob]

Dennis, everything is relative. Maintenance, oil change intervals and driver care or punishment all need to be factored into the equation but it really boils down to this....the more fuel you put through an engine the shorter its' life span.  The larger HP mills won't last near as long as a lower powered engine of the same basic configuration.  In the case of the 2 cycles so common in our buses overspeeding or lugging under load will add to the shortened life span.

I don't know of a magic number I can offer to allay your fears but an engine will generally, not always, give you an indication of a pending failure. In my lifetime I've seen the 71 Series Detroit's still in service long after one would think of as a normal service lifetime.

And I've seen the results of premature failures the cause of which was like finding a needle in a haystack.
So many times I've heard them say of Detroit's, "Run 'em like you hate 'em and you'll love 'em." That might be fine for an operator who doesn't have his money invested in the engine..but for me...I'll run it like the Engineers who designed it would prefer.

NCbob

[JohnEd]

Dennis,

Along those lines..... A while ago I was talking with the owner of Southern Oregon Diesel.  He showed me a converted, just barely, bus on his lot that was for sale.  The basic bus was clean.  I commented on that and he said you should "see" it start up.  I said "see" it start, thinking that was an odd choice of words.  He said "yeah, see, cause it smokes worse than a refinery fire.  He then made a frustrated sound and shook his head and said "I rebuilt this bus' engine less than 9 thousand miles ago and it is ruined already.  He lugged it, I know he must have lugged it".  He was really aggravated by the abuse of machinery and I share that with him.  The point here is that that bus was a standard shift.  He later commented that it was not possible to do that to an automatic.  Food for thought or just added caution?

HTH

John

[tekebird]

a bus with a rebuild with less than 200k chassis miles is one to walk away from in my opinion.  one of it's owners was abusing it.

one should expect to get 500k out of a two stroke DD and then it will still probably run for another 100k...although well down on power

look at the whole bus......if other areas of maint and care were neglected and visually so you can expect other areas that you ccan;t readitly seen to be neglected.

when you look at a bus, go into it thinking it is an airliner you are about to fly on.......things that would scare you on an aircraft should also scare you on a bus.  Although you won;t be falling out of the sky because of them.

[Hi yo silver]

All good points, guys.  Thanks for the feedback.  Makes sense to me.  Stan, I'm not worried about having to rebuild an engine every 250k, just wondering whether I need to factor the expense of an impending rebuild into the cost when I'm buying one.  I wouldn't expect to have to do it more than once, I know how to drive one.  (I drove charters for a couple of years.) All your comments are good and helpful. Thanks!

[tekebird]

what you lookimg to get?

[Hi yo silver]

I'm probably gonna end up buying an MC9, pretty original appearance, not too glitzy inside. I like the Custom Coach conversions, but it won't have to be a CC.  I need a turn-key bus, pretty much.  Not interested in trying to do my own, and don't need a major project.  Minor changes, I can deal with. I've been looking for too long to get in a big hurry now.  I have come close a couple times.  This board and some of you guys in particular, have been an invaluable help in knowing what to check for and how to do it.  Thanks,
Dennis   

[RJ]

Dennis -

Back in the days when Greyhound had one of the most respected PM programs in the country (think 4104/Scenicruiser thru MC-9 days), they would get 500K out of a 71 series.  Then the coach would be pulled into the shop, and 4 - 8 hours later, depending on the model, it would be back on the road with a new powertrain.  Sadly, their PM program today is a joke, and the equipment shows it.

In transit operation, most properties averaged 250 - 300K on a 71 series before overhaul time. 

Besides the Custom Coach units, also consider Angola, Liberty and early Marathons in your search.

FWIW & HTH. . .

[Stan]

Dennis: When you buy a used bus, the standard engine warranty is 30 seconds or 30 feet. Always factor in the cost of an engine rebuild in the price you pay. Obviously this doesn't apply to the people who buy the $2500.00 buses.

[TomC]

When I had two trucks with 6V-92TA and 8V-92TA, both went 500,000 miles before overhaul.  But- there is also a definite schedule of preventative maintenance on the 2 stroke motors that have to be followed to get to that mileage.  The basic is, every 100,000 miles run the rack (adjust the exhaust valves and set injectors); at 200,000 miles roll in new crank and connecting rod bearings; at 300,000 miles rebuild the blower, turbo, and injectors; at 400,000 miles roll in new crank and connecting rod bearings; at 500-600,000 miles new piston rings-or just plainly do a complete in frame overhaul.  On my 8V-92TA, at 500,000 miles, I could have gotton by with just a ring job, but Detroit had redesigned the liners, pistons, and rings to get better oil consumption, so I opted for the upgrade.  As consequence, my oil consumption went from 1200 miles per gallon to 2200 miles per gallon.
Now on modern 4 stroke engines, some will have you adjust the valves at 100,000 miles and roll in new bearings at 500,000 miles.
I know that the new Detroit DD15 that is replacing the Series 60 has an advertised B50 (50% engines will get there and 50% won't) engine life of 1.2 million miles, with 2-4% better fuel mileage than the present Series 60.  Time and technology marches forward!  Good Luck, TomC

[Hartley]

I liked the comment about aircraft...

Jest Ye forget that going down a mountain and missing a turn because your brakes failed
would tend to make the bus into an airplane when you miss that last curve....

Always worry over when the brakes were last done and have them inspected...
The engine will get you to the top, But the brakes have to get you to the bottom...safely!

Yeah.. I am still a little paranoid after crossing Spencer Mountain and Hwy 127 at night in my MC9 ( No Jakes and 8k trailer behind me pushing hard! )... When the sun came up all you could see was sky and deeeeeeeeeepppp valleys.... I have a new route now...

Dave...

[Hi yo silver]

Russ, Stan, Tom,
Thanks for yet some more meaningful info.  All good!  Also, I am checking the sites recommended, pretty much every few days, for new listings.
Dennis