221/239 cranks

flatrod

flatrod

Senior Member
I have a 221 and crank is shot. I have a 239 crank with the same rear seal area, but it doesn't fit the block. What all needs to be done to use the 239? Is it practical?
 
Check the main bearing diameters, Early maind were 2.398/ also the fron and center journals have to be widened about .050" A good crank shop can do it $$$$$
 
The 48 or 91A types use the small con rods too. The 99, 29, & 59A types will use the larger con rods but 8BA stuff can also be used if whittled down a bit. It might be easier to find the right crank. If it's a short snout then look for that. Same thing it its the long snout type. There are still good pre-war 221 cranks out there.
 
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It may be easy to find a 221 crank in the lower 48 states, and while there may be a few around up here, they are not easy to find in usable condition.
 
I'd think a lot of people don't build 221s. So if they don't junk them there are a few out there. Might be easier.
 
rotorwrench said:
There are still good pre-war 221 cranks out there.
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Tinker said:
I'd think a lot of people don't build 221s. So if they don't junk them there are a few out there. Might be easier.
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This is true, and since I've bought and been gifted, plus also mainly use the early, pre war 221ci engines, I have a bunch of these crank shafts sitting around that I'll never need or use, but shipping to Alaska won't be cheap.
 
Just to make things clear. From Late 38. up, all crankshafts will fit. However, in the early blocks you may not be able to use the rod assemblies. For the 36LB thru early 38 the 2.398 main blocks, you have to modify the 2.498 cranks.
Yes, you can put a 4" Merc crank in a 36 LB block, but it aint easy$$$$
 
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