46 M

Jim McVay · Sep 8, 2012

An older club member with a 46 M would like me to rebuild his orginal M to get some more HP out of it. It is bone stock. He would probably be happy with 60 HP. Not sure what heads are low and high compression. What are the head #s? Can you get pistons for the low compression heads to make the engine high compression? I mainly work on CASE tractors but may try to help this old timer out. I know you get what you pay for. Any suggestions?

randy hall · Sep 8, 2012

8060 or 8574 are m gas heads. 362174 is a 400-450 gas head 364586 is a 450lp head [ the best option]. you can't buy pistons to make an old low compression head 8777 work.

LarryM · Sep 12, 2012

The easiet way to get 60 horse is to go with the 4" red power pistons that are the same as the old IH fire craters and a new re-casted LP head. Then find an original 450 manifold in good shape and then put a bigger venturi in the carb. A 32 would work well. Drill out the main jet and with the right fuel you probably would have at least 65 horses. If you want to go lower cost then finding a good 450 head would get you close to or at 60 hp. If the governor is wore that will need to be rebuilt as well. I have 67 hp at 540 PTO coming out of a 450 engine that is all stock except the carb and the dome pistons. It is still just an 8:1 compression engine.

dej(Jed) · Sep 13, 2012

(quoted from post at 18:23:34 09/08/12) An older club member with a 46 M would like me to rebuild his orginal M to get some more HP out of it. It is bone stock. He would probably be happy with 60 HP. Not sure what heads are low and high compression. What are the head #s? Can you get pistons for the low compression heads to make the engine high compression? I mainly work on CASE tractors but may try to help this old timer out. I know you get what you pay for. Any suggestions?

60 HP out of an M with 4 inch pistons? Amazing...

rustyfarmall · Sep 13, 2012

(quoted from post at 06:12:22 09/13/12)

(quoted from post at 18:23:34 09/08/12) An older club member with a 46 M would like me to rebuild his orginal M to get some more HP out of it. It is bone stock. He would probably be happy with 60 HP. Not sure what heads are low and high compression. What are the head #s? Can you get pistons for the low compression heads to make the engine high compression? I mainly work on CASE tractors but may try to help this old timer out. I know you get what you pay for. Any suggestions?

Click to expand...

60 HP out of an M with 4 inch pistons? Amazing...

I agree. 50 horsepower would be just the max.

46 M

Jim McVay

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randy hall

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LarryM

Member

dej(Jed)

Well-known Member

rustyfarmall

Well-known Member

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