Life expectancy of a 6V92?

[MCI-RICK]

How many "hours" should a 6v92 last?  I understand the answer would have to assume good or average maintenance.  Does anyone know?

Rick   

[TomC]

Both my 8V-92TA and 6V-92TA lasted 500,000 miles before first overhaul in my trucks.  If you take an average of 50mph, then that works out to be 10,000 hours between overhaul.  Course, there is scheduled maintenance between those numbers.  On 2 stroke engines, the rack should be run every 100,000 miles; main and rod bearings should be rolled in every 200,000 miles; injectors should be pulled and pop tested every 300,000 miles along with having the blower and turbo overhauled.  All in all, the 2 stroke engines are maintenance intensive, compared to the new 4 stroke engines that just require an initial valve adjustment at 60,000 miles, then when ever power loss is felt-and no scheduled injector or bearing replacement in 1.2 million miles.  Good Luck, TomC

[MCI-RICK]

TomC,

I appreciate the detailed and thorough response, thanks!  BTW, I didn't know 4 stokes were so reliable.  What's their drawback?   

Rick   

[belfert]

The main drawbacks of a 4 stroke are cost and most of them being electronic.  The electronics can be hard for the average busnut to work on.  Another drawback can be mileage, but only on the newer ones with EGR and such for emissions.  Even an emissions controlled 4 stroke should get as good of mileage as a 2 stroke.

Buses with factory 4 strokes are still fairly expensive because the bus will be newer and likely 45 foot.  45 foot buses are becoming the standard for charter operators these days.

[uncle ned]

If the temp guage gets to about 220 to 230,  they last about 2 minutes. don't ask how I know.

uncle ned

[MCI-RICK]

Uncle Ned,

My wife and I are here laughing!  I'll probably remember that every time I glance down at the temp gauge.  Thanks. 

Rick 

[belfert]

Drawbacks of the 4 stroke repower:

1. Need to engineer motor mounts.
2. Engine may be too tall or long depending on engine choice.  Length may preclude use of the HT740 in some buses
3. Must build a wiring harness in almost all cases.
4. New tranny may be required.  See #2.

I'm all for 4 stroke engines, but someone asked for drawbacks.

[TomC]

The main reason 2 strokes were used in buses was because they had the highest power to weight ratio.  Now with electronic 4 strokes, that all goes away in favor of excellent fuel mileage (even with EGR equipped trucks).  My 8V-92TA mechanical truck averaged 4.8mpg.  EGR equipped Series 60's are getting about 6-6.5.  The new DD15 (also EGR) in one instance, a driver going between Salt Lake City and Phoenix-which isn't flat-grossing close to 80,000lb, but with the engine programmed for progressive shifting, and governed at 62mph, has gotton a life time average of 7.6mpg in the first 150,000 miles.  Even the electronic 2 strokes would only get about 6mpg in trucks.  I'm looking forward to 2010 when Urea exhaust fluid injection will facilitate backing off on the EGR and we should see 80,000lb trucks getting towards 8mpg!  Good Luck, TomC

[RJ]

I appreciate the detailed and thorough response, thanks!  BTW, I didn't know 4 stokes were so reliable.  What's their drawback?   
 

Rick -

For us old-timers, the biggest drawback to the four-stroke diesel is that they don't SOUND like a two-stroke!

http://www.pacbus.org/flash/detroit.swf

FWIW & HTH. . .

[Dreamscape]

RJ, That looks like the bus I saw at Coach Maintenance that I saw him painting last year, is it the same one?

~Paul~

[luvrbus]

Rick, to answer your question about the hours of life for a 6v92 in my Bomag recyclers 350 Hp they would last around 17 to 18,000 hrs,

The 60s,Cat C series,Cummins,John Deere,and the Volvo engines I owned would run about the same hrs

When you run the 4 strokes at 2100 rpm day in and day out in equipment their life is shorten by a bunch 

When comparing the engines most of these guys compare the 2 strokes from years ago to the late model 4 strokes but in their day the 2 strokes were as good as any on the market.
No engine had a  better warranty in it's time they have severed me great over the last 30 years



good luck

[MCI-RICK]

Thanks for all the info everyone!

I have a related question.  I've read that I could run my 6V92 at 2100rpm all day with out a problem.     But, should I?  I thought 2100rpm was max engine speed?  My bus has a good engine that I don't want to overhaul prematurely due to running it near or at max engine rpm regularly.  So, who's got the scoop on this?  or Who's got the 6V92 bible?

Rick 

[JackConrad]

Thanks for all the info everyone!
   I have a related question.  I've read that I could run my 6V92 at 2100rpm all day with out a problem.     But, should I?  I thought 2100rpm was max engine speed?  My bus has a good engine that I don't want to overhaul prematurely due to running it near or at max engine rpm regularly.  So, who's got the scoop on this?  or Who's got the 6V92 bible?
Rick 

Depends on your gearing and how fast you want to go LOL.  I don't think it would hurt it but what speed will that be and do you want to maintain that speed?  On our bus, that would be between 70 & 75. We prefer to run about 62-62 (about 1850-1950 RPM)  Jack