Anyone know if this engine is worth buying?

[nomadd]

2002 Chevrolet Bluebird gasoline bus, 8.1 Chevrolet engine. Allison transmission, air brakes with 185,000 miles


Haven't considered gasoline motor before now and not sure. Can anyone talk me out of getting a gasoline engine?


Don't really understand what the trade-offs are besides lifetime. Which leads me to wonder if 185,000 is close to replacement. It's from a bus barn and just decommissioned so well maintained I assume.


Thank you!

[CHEESE_WAGON]

From what I understand, an 8.1 Vortec is a stroker Gen V big-block. 502 CID. Pretty reliable, all the U-Haul trucks have them and I haven't heard anything bad about them. I've seen 6.0s with 300k+ and still stroking, the 8.1 wouldn't work as hard, so there is that. With the emissions control problems with diesels, I'd say it's worth a look. Probably has an AT545 though. Which isn't terrible, but not great either.

[nomadd]

Thank you!


Seller doesn't know tranny model but says it will do 70mph. Just requested the VIN. How do I look the vin up?

[Oscar1]

Originally Posted by nomadd

Thank you!


Seller doesn't know tranny model but says it will do 70mph. Just requested the VIN. How do I look the vin up?

Something else to consider is mileage. Do you plan to drive 500 miles a year or 5000? that gas motor will get approximately half the fuel economy of a diesel engine with similar horsepower and the diesel will still have more torque for better pulling power.

[nomadd]

Thank you Oscar. Half you say? I keep seeing 70% efficiency comparison.


Plan on taking it on some steep hills in the Ozarks and thinking the gas will be better for that. You think diesel will be fine.


Seller says he never checked but assumes 8-10 miles/gal.

[CHEESE_WAGON]

Originally Posted by nomadd

Thank you!


Seller doesn't know tranny model but says it will do 70mph. Just requested the VIN. How do I look the vin up?

Here's one source that might provide helpful info.

http://cmvid.nisrinc.com/CMV_ID/CMV_ID.asp

Here's some other info on trans ID.

[JackE]

Couple things to consider.
There are probably thousands of motor homes rolling down the road with that 8.1L.
They don't make that engine anymore.
My uncle just had to have his rebuilt, about 175K miles, it cost him almost $4K.

[EastCoastCB]

Originally Posted by nomadd

2002 Chevrolet Bluebird gasoline bus, 8.1 Chevrolet engine. Allison transmission, air brakes with 185,000 miles


Haven't considered gasoline motor before now and not sure. Can anyone talk me out of getting a gasoline engine?


Don't really understand what the trade-offs are besides lifetime. Which leads me to wonder if 185,000 is close to replacement. It's from a bus barn and just decommissioned so well maintained I assume.


Thank you!

Its a great engine. Don't expect awesome mpg's but its a good powerful reliable engine.

[Oscar1]

Originally Posted by nomadd

Thank you Oscar. Half you say? I keep seeing 70% efficiency comparison.


Plan on taking it on some steep hills in the Ozarks and thinking the gas will be better for that. You think diesel will be fine.


Seller says he never checked but assumes 8-10 miles/gal.

You didn't tell us the size or gvw of the bus but I think 70% or 10 miles to gallon both would be very optimistic. Again if you're only drive a few miles a year no problem but if you're planning big trips it's going to add up. I'm not saying there's anything wrong with that engine but in its intended use as a school bus in a district speeding tax payers money that would not be their first concern. Short runs, an hour in the morning and an hour in the evening.

[cadillackid]

alot of the 8.1's 2000 and newer got the allison 1000 transmission

[CHEESE_WAGON]

Originally Posted by cadillackid

alot of the 8.1's 2000 and newer got the allison 1000 transmission

CK, I had heard of the 1000 but wasn't sure what it was used in. How to identify?

[cadillackid]

a pic from underneath is the best way.. it looks similar to an AT545 but with a wide tailshaft that has a ring of bolts around it and a round wire harness going into the left rear of the trans.. .. essentially the 1000 was a stock trans used in many vocations.. off the shelf per se'. the 2000 and 1000 are very simiular but the 2000 is deisgned based on vocation and has somewhat different gear ratios available.



the 8.1 is the only GM gas engine I know that got the 1000. the 5500/6500/7500 chassis (Uhauls mentioned earlier) all had the 1000.. in the bus chassis im guessing the shifter is a way to ID it.. by a R-N-(D)-D-2-1 or R-N-D-4-2-1 pattern just like the 2000.

[Ronnie]

A picture of the data plate on the trans will tell you what model too.

[nomadd]

Originally Posted by CHEESE_WAGON

CK, I had heard of the 1000 but wasn't sure what it was used in. How to identify?

Is the 1000 worthy?


And thanks for the VIN link. I'm feeling this bus more than any of the other hundreds I have looked at.

[nomadd]

GVWR is Class 7. 26K-33K

[EastCoastCB]

Originally Posted by nomadd

Is the 1000 worthy?


And thanks for the VIN link. I'm feeling this bus more than any of the other hundreds I have looked at.

Yeah. Lockup TC and OD. Very good.

[nomadd]

Originally Posted by EastCoastCB

Yeah. Lockup TC and OD. Very good.

Thank you, I'm not sure what your sentence there means. Sorry, complete newby and learning more. Appreciate you sharing.



What does "lockup TC and OD" mean?

[EastCoastCB]

It has a locking torque converter unlike the slip-o-matic 545. SO it has engine braking when descending steep hills. It also doesn't cause excess heat to be built up from the slipping at highway speeds so the engine runs cooler. OD is overdrive. That means it has a top gear higher (numerically lower) than 1:1. Meaning that in top gear the engine is spinning as fast so better mpg's and less engine heat.

[TomA]

The Vortec 8.1 is a very good engine. Out of production, but super torquey, still in use everywhere and doesn't really have any flaws other than thirst. See here:

https://www.youtube.com/watch?v=I3smlO7dHHo

If you have one and are going to drive it a lot, a GearVendors OD, a taller rear axle ratio swap, or even both changes together would probably payback the mods in fuel economy and reduced wear before long. Unlike a diesel, lightly loaded gas engines are perfectly happy to loaf along at low rpm on level ground. That saves A LOT of fuel. They start better in the cold, too, and are much quieter and smoother to drive.



BTW, $4k for a rebuild is less than half what any diesel would cost to rebuild, let alone a Cat...

[EastCoastCB]

I'd definitely be interested in an 8.1/1000 GMC shorty.