Super M- 450 help

Shawn W · Aug 3, 2008

Hello
I have a 1949 M with a super m motor it has firecrater pistons and number 3 rod is out the side of the block, nice big hole in side.
THis is not a pulling tractor but a tractor i mow with and pull a oliver 4-14 plow.
I bought a 400 block on ebay and it turned out to be a C-281 block when it arived. My crank is is fixable. I was wondering if anybody can tell me what rods i need to look for and what i should order from CaseIH. For $600 i can get a complete rebuild kit with gaskets, bearings, sleeves and pistons and everything i need. But will everything work with the 281 block and what rod part number do i need to find. Getting ready to tear apart this week, I would really like to have tractor back in field this fall
Thanks
Shawn

D Slater · Aug 3, 2008

Depends, on M through 450 there was 2 bore sizes in bare blocks, 2 size rods on the piston pin end, and 2 size crankshaft journals. Parts can be mixed and matched in most cases.
If you want to use the more common rod with big piston pin bushing, get pistons and sleeves for a SM or some 400 in 4 or 4-1/8 inch size. If you end up with pistons that have the 1 inch small pin like used in some 400 and all 450 tractors, they sell adapter bushings for small end of early type rods or use rods from 400 or 450 with small end. If you realy have a SM crankshaft, it uses the same bearings that a C281 does. If you have a crankshaft from all but late M, you need to use the M bearings in the 281 block and rods for crank to work. Any piston sleeve set for a SM, 400 or 450 will work in a C281 block as long as other parts are used to match. Before deciding which piston top shape you want, you may want determan which head is being used.

Shawn W · Aug 4, 2008

Ok
Thanks for the info. I believe the head is a 8060. my block bore was 4.25" does that mean all blocks was the same bore?

D Slater · Aug 4, 2008

C-264 and C-281 came with a sleeve removed bore of 4.250 or very near. Original C-248 or M engines used a 4.125 bore without sleeves. All the blocks used the same size holes for main bearings. All connecting rods used the same size opening in big end for rod bearing. All but some of the latest M tractors used a crankshaft with smaller journals than C-264 and C-281 did. C-248 used thicker bearings for the smaller journal crankshaft and thiner bearings were used with big journal crank in late M,SM,400 and 450.

Super M- 450 help

Shawn W

Member

D Slater

Well-known Member

Shawn W

Member

D Slater

Well-known Member

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