Harvester 6.9L Diesel Engine

[khelek41]

I am currently looking at a 40' 1987 bluebird that has a Harvester 6.9L Diesel engine and an Allison automatic transmission and I wanted to make sure that that engine is powerful enough to handle the weight of a conversion. I don't know a ton about engines. I know everyone talks about the Cummins as the best option but this is a really good deal. Does anyone have any experience/opinions on this type of engine? Its got 240,000 miles on it but appears to be in good condition (well maintained). I'd really like to get everyone's feedback on this.

Thanks!

[Booyah45828]

I have that in a 38ft conventional. Will do 70 on flat ground. That's more then likely na so hills will be a problem. You can buy turbo kits for them and double the hp if you're so inclined.

[BeeLDub]

Originally Posted by khelek41

I am currently looking at a 40' 1987 bluebird that has a Harvester 6.9L Diesel engine and an Allison automatic transmission and I wanted to make sure that that engine is powerful enough to handle the weight of a conversion. I don't know a ton about engines. I know everyone talks about the Cummins as the best option but this is a really good deal. Does anyone have any experience/opinions on this type of engine? Its got 240,000 miles on it but appears to be in good condition (well maintained). I'd really like to get everyone's feedback on this.

Thanks!

Originally Posted by Booyah45828

I have that in a 38ft conventional. Will do 70 on flat ground. That's more then likely na so hills will be a problem. You can buy turbo kits for them and double the hp if you're so inclined.

I have a 37ft International Wayne Lifeguard with that engine (not sure about tranny). I live in the hills, and it slows down quite a bit on the steep ones if I don't already have some speed, but it keeps going no problem!

On the highway, I'm geared for TOP speed around 65mph, I like to keep it around 55-60. When I hit an incline at those speeds, it can keep its speed pretty well, it's rare I had to put my hazards on.

As for the turbo, I *read* that they had a tendency to destroy the engine. From my understanding, the engine was adapted from their gasoline version to run diesel, and it did so well, but not as efficient if it were designed to be a diesel from the start. With that, there was a manufacturer version that came with a turbo to improve performance, but they caused those engines lots of issues. When I was bus shopping and found several engines like these, I was warned to stay away from the turbos.

Hope this helps!

[Booyah45828]

Originally Posted by BeeLDub

As for the turbo, I *read* that they had a tendency to destroy the engine. From my understanding, the engine was adapted from their gasoline version to run diesel, and it did so well, but not as efficient if it were designed to be a diesel from the start. With that, there was a manufacturer version that came with a turbo to improve performance, but they caused those engines lots of issues. When I was bus shopping and found several engines like these, I was warned to stay away from the turbos.

It was designed as the gas engine replacement. But was never a gas engine, or adapted from one. As far as turbo kits go, you might run into head gasket issues with too much boost but that's routinely fixed with head studs. oilburners.net is a good forum for both the 6.9 and 7.3 idi if you're inclined to read more on upgrades.

[khelek41]

I'm glad to hear that it's a decent engine. I know for a fact that it doesn't have the turbo, so that sounds like it's a plus. Is 240k miles ok for that kind of engine? How much mileage do those engines usually get if maintained property?

[BeeLDub]

Originally Posted by khelek41

I'm glad to hear that it's a decent engine. I know for a fact that it doesn't have the turbo, so that sounds like it's a plus. Is 240k miles ok for that kind of engine? How much mileage do those engines usually get if maintained property?

Mine only has 147K miles, so I can't speak from experience, but I've heard good things!

[Skipoffools]

Originally Posted by khelek41

I am currently looking at a 40' 1987 bluebird that has a Harvester 6.9L Diesel engine and an Allison automatic transmission and I wanted to make sure that that engine is powerful enough to handle the weight of a conversion. I don't know a ton about engines. I know everyone talks about the Cummins as the best option but this is a really good deal. Does anyone have any experience/opinions on this type of engine? Its got 240,000 miles on it but appears to be in good condition (well maintained). I'd really like to get everyone's feedback on this.

Thanks!

I have a 6.9 with a banks turbo in my f250 and I just pulled a 16x80 single wide the other day. Probably over 20k lbs, and it didn't even stutter. The 6.9 is the precursor to the infamous 7.3 idi. Meaning InDirect Injection. the 6.9 is less prone to cavitation because the 7.3 is an over bored version of the same block. Little less horsepower than a 7.3, but makes up for it in durability. Make sure (as with all buses) you pay attention to SCA levels in your coolant, and it should easily make another 240k mi.

I have a dta360 in my bus and I like to think of the 6.9 IDI as the little brother of the 7.3 IDI, and the DTA360 as the little brother of he DT466

6.9 IDI is the tortoise as opposed to the hare. It will pull it and finish the race but it may not do it fast.

Like I said I'm speaking of experience of my 6.9 in my PICKUP. So it maybe a different story in a bus.

Check out dieselstop and oilburners, they are both forums with lots of info on these engines.

[splitsvillage]

Do buy it Kehelek. Especialy if the bus is in good shape. I have one with similar mileage (albiet with a 5spd) that doesn't hesitate to go.

They are robust, economical, engines. The s1700 bus engines were tuned-down compared to the light ford trucks; i.e. there were smaller injector nozzles and tuned down injector pump for efficiency. modest gains in power could be had by replacing with ford truck injection parts if I"m not mistaken.

More modern diesel's will prove more road-able, but what race are you planning to run? it's old. I like old.

[Skipoffools]

Originally Posted by splitsvillage

Do buy it Kehelek. Especialy if the bus is in good shape. I have one with similar mileage (albiet with a 5spd) that doesn't hesitate to go.

They are robust, economical, engines. The s1700 bus engines were tuned-down compared to the light ford trucks; i.e. there were smaller injector nozzles and tuned down injector pump for efficiency. modest gains in power could be had by replacing with ford truck injection parts if I"m not mistaken.

More modern diesel's will it's old. I like old.

I agree I like old too.