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bulli
New Member
Germany
4 Posts |
 Posted - 09/06/2005 : 2:03:05 PM
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1977 loadstar schoolbus diesel conversion.
Thanks for the replys on the initially quoted 345 engine disaster.
After several days of search for an 392 to replace the destroyed 345 for our restored schoolbus we decided to swap a diesel since gas prices are exploding here in germany: more than 5 dollars per gallon. The 392 is obviously a good gas engine, but the risk to ruin it by going faster than 3900 rpm is too high.
Does anybody know wether a 6.9 navistar diesel out of an 1983 IHC stake truck will fit under the short nose, bat-wing type hood of a 1977 schoolbus? I was offerd this truck from close by, so no shipping
headaches. Only 45.kmls on the clock and running really well.
Next problem is no compressor on the diesel which I need for the bus air brakes. Any suggestions where to find a matching compressor . Needs to be mounted on the right front side of the engine.
Thakns for the support again.
Nao
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Craig Thoricht
Senior Member
USA
177 Posts |
Posted - 09/07/2005 : 02:59:53 AM
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The 6.9 liter diesel was based on the old MV 446 gas engine and as such require engineering mounts/ exhaust/ glow plug wiring and throttle linkage. Cooling will also be an issue and engine placement in the engine compartment will be dependent on where the radiator/ shroud is placed.
You are going to have an interesting project on your hands.
There are any number of salvage yards here in this country for air compressor and brackets. If you are intersted you might want to call Myers Equipment in Canfield, Ohio at 1-800-232-7649. They could help with shipping and customs issues. Don't forget that the compressor will have to be driven by belt from something on the front of the engine so you will also need that pulley assembly from a donor engine. |
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bulli
New Member
Germany
4 Posts |
Posted - 09/07/2005 : 12:04:07 PM
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Thank you very much for the hints. Emailed myers.equip. right away.
Waiting for response.
Appreciate your help.
Nao
quote:
Originally posted by Craig Thoricht
The 6.9 liter diesel was based on the old MV 446 gas engine and as such require engineering mounts/ exhaust/ glow plug wiring and throttle linkage. Cooling will also be an issue and engine placement in the engine compartment will be dependent on where the radiator/ shroud is placed.
You are going to have an interesting project on your hands.
There are any number of salvage yards here in this country for air compressor and brackets. If you are intersted you might want to call Myers Equipment in Canfield, Ohio at 1-800-232-7649. They could help with shipping and customs issues. Don't forget that the compressor will have to be driven by belt from something on the front of the engine so you will also need that pulley assembly from a donor engine.
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Dieselmech
Active Member
USA
10 Posts |
Posted - 09/16/2005 : 08:47:42 AM
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I believe a 6.9 should fit. If you have ever done a engine conversion before it should not be to much trouble for you. Here are some thing's to keep in mind though. Your transmission and rear axle gear final drive ratio is made for use with a gas engine that run's at much higher RPM's than a diesel engine. If you just drop in a diesel engine you could expierence a speed drop of 25% or more due to the diesel engine's slower engine speed, not to mention the horrible fuel economy you would get because you would have the gas(diesel) pedal pushed to the floor all the time. You will need to change your rear gear set to a lower ratio (higher numerically). In most cases a change from gas to diesel should also include a gear set with at least a 1.00 numerically higher final gear ratio. You can acomplish this with a rear gear change or if you can find a manual transmission with a overdrive gear that could be another option.
Some other considerations for you are have you thought about a inline engine??? 6.9's in my opinion are all but boat anchors. No power and not enough torque to even pull a pick-up truck. Diesel engines in a inline configuration by nature have a much higher torque curve and in a more useable area of the RPM band. I think International and Caterpillar engines may be a little to large for you but if you can lay your hands on a older Cummins inline 4 cylinder you would have something (or 5.9 6 cylinder if you have room under the hood). It may be a small engine (just a 5.9 minus 2 cylinders) but with some injection pump tweeking and a set of gen-set injectors you can make a 3.9 Cummins out pull 6.9 International's all day. The inline engines are built alot stronger and in your case just the fact that it is smaller would be a major plus. If your looking to drag race I could build you a 3.9 that put's out about 1,200 HP :) A friend of mine has a 5.9 in a pulling tractor and he has gotten it to 2,012 HP on a dino. Amazing what a set of 4 turbo's, custom aluminum cylinder head and some major fuel system upgrades can do, and did I mention a bottomless wallet.
In any case don't let anybody tell you something won't fit or won't work. Anything is possible, just some thing's work better than others. |
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1977 Schoolbus diesel conversion
