Upgrading A 237

[Bliue dm]

As a kid I knew a guy who had a 237 that pulled like a 300. It was an R model tractor turned into a dump truck. I was talking to a friend who use to drive one of the DMs for my grandfather. He told me that back in the day alot of guys where taking the sleeves and pistons for a 300 and putting them into a 237. Know I have searched and searched and have no success finding info on this topic. Also if somebody can give me a link that shows the difference in the older mack motors that would be great.

[Rob]

As a kid I knew a guy who had a 237 that pulled like a 300. It was an R model tractor turned into a dump truck. I was talking to a friend who use to drive one of the DMs for my grandfather. He told me that back in the day alot of guys where taking the sleeves and pistons for a 300 and putting them into a 237. Know I have searched and searched and have no success finding info on this topic. Also if somebody can give me a link that shows the difference in the older mack motors that would be great.

To the best of my limited knowlege there is no difference in the pistons and liners between the two engines. They are both Maxidyne series. The differences are in the injection cycle dictated by the injection pump governor settings, and timing of the injection cycle. A sound 237 Mack engine will reliably output 300 horsepower and plenty of torque with some type of charge air cooling, and recalibration of the injection pump assembly. This is a balance power package and only working with part of the system will not yield the long term durability if this balance is upset.

If you recalibrate the pump from the Maxidyne series settings and don't install a transmission with more gears, (Maxidynes typically had five, or six speeds) the engine will seem to fall on it's face as the spread is too wide.

Rob

[other dog]

To the best of my limited knowlege there is no difference in the pistons and liners between the two engines. They are both Maxidyne series. The differences are in the injection cycle dictated by the injection pump governor settings, and timing of the injection cycle. A sound 237 Mack engine will reliably output 300 horsepower and plenty of torque with some type of charge air cooling, and recalibration of the injection pump assembly. This is a balance power package and only working with part of the system will not yield the long term durability if this balance is upset.

If you recalibrate the pump from the Maxidyne series settings and don't install a transmission with more gears, (Maxidynes typically had five, or six speeds) the engine will seem to fall on it's face as the spread is too wide.

Rob

just taking the cover off the top of the pump and "giving 'er a couple of rounds" (turning the fuel up) will make a 237 go like a scalded dog. Little dab'l do ya'. Used to be a sure fire way to get fired, breaking the seal on a pump. If it's your own truck you'll have to fire yourself if you turn it up.

[Kav]

just taking the cover off the top of the pump and "giving 'er a couple of rounds" (turning the fuel up) will make a 237 go like a scalded dog. Little dab'l do ya'. Used to be a sure fire way to get fired, breaking the seal on a pump. If it's your own truck you'll have to fire yourself if you turn it up.

I agree but what he was originally referring to is the early maxidyne pistons that we had here used to burn up and fail if you gave it too much fuel. When the Econodyne series with the front intercooler was released they fitted better pistons to them with a better insert around the top to stop them burning. At the same time they fitted heavier Con Rods as some of the earlier maxidyne rods failed. We used to set the 237 pumps up to the specs of the 285 and fitted 285 turbos, but you have to watch the Pyrometer on a long hard pull to keep the heat under control. As Rob said you need a 10 or 12 speed transmission to get the best out of them.If you increase the torque screw, the extra fuel at low revs puts a lot more strain on the bottom end of the motor and the early blocks were not as heavy as the later E6 blocks. Best regards - Michael.

[other dog]

I agree but what he was originally referring to is the early maxidyne pistons that we had here used to burn up and fail if you gave it too much fuel. When the Econodyne series with the front intercooler was released they fitted better pistons to them with a better insert around the top to stop them burning. At the same time they fitted heavier Con Rods as some of the earlier maxidyne rods failed. We used to set the 237 pumps up to the specs of the 285 and fitted 285 turbos, but you have to watch the Pyrometer on a long hard pull to keep the heat under control. As Rob said you need a 10 or 12 speed transmission to get the best out of them.If you increase the torque screw, the extra fuel at low revs puts a lot more strain on the bottom end of the motor and the early blocks were not as heavy as the later E6 blocks. Best regards - Michael.

Yeah, I don't know about all that stuff. I'm just a truck driver, and that's what we used to- I meant, that's what I heard of other drivers doing. Guess that's why it was a good way to get fired. I always went by "don't mess with it if you don't know what you're doing" so I never touched nuthin'.

[vanscottbuilders]

So - If a 237 can accept the innards from a 285/300 -

Is the block any different between the various six cylinder Maxidyne variations?

I have a freshly rebuilt tip-turbine ETZ-675 285 hp that was carelessly left to freeze with only test water in it. (Not by me by the way!)

The crack is really too big to confidentally repair. But all of the inside parts, turbocharger and intercooler parts, and fuel pump are either remanufactured or brand new.

I need a good block, and I'm wondering what will work?

Thanks,

Paul VS

[Rob]

So - If a 237 can accept the innards from a 285/300 -

Is the block any different between the various six cylinder Maxidyne variations?

I have a freshly rebuilt tip-turbine ETZ-675 285 hp that was carelessly left to freeze with only test water in it. (Not by me by the way!)

The crack is really too big to confidentally repair. But all of the inside parts, turbocharger and intercooler parts, and fuel pump are either remanufactured or brand new.

I need a good block, and I'm wondering what will work?

Thanks,

Paul VS

They are very similar with strengthening in the later style castings to combat fatique. I have a block that dropped a valve but was running when I got it. It too is an ENDT-676 engine. Just use all new gaskets, seals and bearings that are pressed into the block after hot tanking the donor. It has been in the weeds for a couple of years but still complete minus the ancillary bolt on parts. It would probably work for you after cleanup. It's not going anyplace so if you don't find another we'll get it to you at some point.

Rob

[HK Trucking]

They are very similar with strengthening in the later style castings to combat fatique. I have a block that dropped a valve but was running when I got it. It too is an ENDT-676 engine. Just use all new gaskets, seals and bearings that are pressed into the block after hot tanking the donor. It has been in the weeds for a couple of years but still complete minus the ancillary bolt on parts. It would probably work for you after cleanup. It's not going anyplace so if you don't find another we'll get it to you at some point.

Rob

Rob, is that the one you got from up here?

.

[vanscottbuilders]

Thanks Rob,

That block might work out real well.

I'll look around locally, but not holding out any great hopes.

The truck I need to bring everything home from out West keeps getting bigger and bigger!

PVS

[theakerstwo]

The 237 needs the main brg struts or brakets to the bottom of the block to make a 300 and the rods are different.If i am not forgeting the rods are a bigger and i think agin hope i ant wrong but have a bigger wrist pin.But i can not see any difference in the block. I was told the 285 and 320 had more metal in the main brg to block gussets.This is were a 237 will break if you mash on a maxidyne too hard if the fuel is set to hot.The injectors was poping higher but that only gives it a better burn but no more fuel.Turbo will be better and most 300 had the ambac pump.But a 237 with more fuel and the main brg plates will work better than a 350 cummins if you have a 10 speed or 12 speed.

[Rob]

Rob, is that the one you got from up here?

.

Hi Herb, no, the engine I picked up from your area is in Morgan's B-61 now. It was not planned this way but it never made it home with me. I had borrowed Morgan's trailer to pick up an R model cab, and the engine. After unloading the cab at my shop I was going to have Morgan look the engine over for me but I had no real use for it at the time, so we traded it out. It really seems to be a good runner too but I don't know if it's ever pulled a load. This old block is from a 77 R686 I put a 237 and all the original 285 plumbing on many years ago. It ran but had a dead miss on one cylinder. I've never pulled it apart. This is the engine I rebuilt the oil cooler on and installed onto my B67 as the original cooler was not salvagable.

Rob

[Bliue dm]

This 237 would be in front of a quad. That should be enough gears right. I don't want to do anything that would shortened the life of the motor. He said that this is what the did and it worked well so I was trying to see if some of u other guys did it. This 1979 mack with this upgraded 237 had a pyrometer in it to

Edited March 30, 2010 by blue dm

[GreenGiant2]

Thanks Rob,

That block might work out real well.

I'll look around locally, but not holding out any great hopes.

The truck I need to bring everything home from out West keeps getting bigger and bigger!

PVS

HEY PAUL

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