Gas To Diesel

[Charlie Hatfield]

I have bought a mack 237 turbo'd engine out of a "B" to put in my "L" fire truck in place of 707 gas engine. I need to know what problems I will have with any changeover situations. I have never done this before and would like to talk to someone who has. Someone told me to use the water pump out of the "L" to make the fan blade fit. Since it is a fire truck, I am also at a loss as to what kind of oil filter assy to use and also air cleaner. The diesel look like it has bolt-on rear mounts(gone) and on the gas, it is part of flywheel housing. Also the transmission (TR720) I am going to use looks like it needs an adaptor ring to fit the engine.

Also I am curious as to where the vacuum is(for wipers). Once I start changing everything,I want to be able to finish it, with no problems or wrong parts.

[Lmackattack]

sounds like a project on your hands..LOL

if the 237 has a oldstyle luberfinder setup you could simply remove the oil lines and filter assy from the block and get the spin on filter adapter that bolts to the pass side of the engine. then you could use the easy 2 spin on filters

fram what I have heard with people installing 237s in b models is that the 237s pully on the water pump extend farther out than the thrmodynes engines, you may only need to replace the pullys ??? as far as the rear engine mounts its a loss to what would work. hopefully a diffrent bell housing will solve the trans/engine connection. I cant remember if the rear mounts are on the bell housing or trans??? so cant give a suggestion there

let us know what works.

I have some R model frame mounts on a scrap truck in the yard. If you need then i will pull them off for you no charge but shipping

trent

[Superdog]

Charlie,

You will probably have to do a little fabricating.There haven't been alot of Maxidynes put in L's.The only guy I know of that has a 237 in a L fire truck is Cal Little.You might wanna try to get ahold of him.I don't think your 707 waterpump will work on a 237.The rear engine mounts were usually bolted to the trans. on the diesels.If I was you,I believe I'd go with a newer TR1076 transmission,these are plentiful and usually pretty cheap,and should remedy your bellhousing problem.I'd go with a dry type element air cleaner off a R or U 685.These are a little smaller than the single outlet air cleaners on the later model 686 and 688's.You'll have to go to air or electric wipers,also.You also don't want to forget that your rear end will be of a ratio best suited for a gas engine,you'll have to change that also.

[Charlie Hatfield]

I got the numbers off the engine, END 673-215-23. The number on the turbo is 631gc549bp7. It has an American Bosch injector pump. Since it does not have a "T" in the model number, a friend told me to check for piston coolers inside the engine. Also the transmission will bolt to the engine. I do not know if the "L" rear engine mounts can be moved and everyone tells me that there were never any mounts bolted to the diesel engine. Even new trucks are that way. I am not familiar with "B" that much so am not sure as to how to procede with this changeover

[Superdog]

You got a 170 hp 673 somebody slapped a turbo on,not a 237,those were the ENDT675.The 673 never had the provisions for oil cooled pistons so you really have to be careful not to cook it.I'm not sure how much hp just adding a turbo to one would add,but the factory ENDT673 was 205 hp,and later in the '60s raised to 225 hp,and the ENDT673C was 250 hp.Hope you didn't pay 237 price for your 673.

[Lmackattack]

correct me if im wrong ...to add piston coolers to the END673 you could "simply" tap into the oil gally??? I heard that from someone that added a turbo to there non turbo 673

trent

[b61fred]

correct me if im wrong ...to add piston coolers to the END673 you could "simply" tap into the oil gally??? I heard that from someone that added a turbo to there non turbo 673

trent

←

charlie,

does your truck have a vacuum brake booster? vacuum wipers? and that vacuum cylinder that turns on the big waterpump on the fire aperatius? other than that the motors should be close to the same as the 707, I still have all those mounts on my firetruck and the ones on the frame to mount the trans. If you need that stuff call me.

Fred