"440 source" (stroker kits) for a mid 1970's 440 motor. Cylinder material removal for rod clearance.

Doesn’t it end up being a little dish shaped as you approach the journal radius?

dvw said:

I find it hard to believe anyone could polish .001" from a crank. It would take forever.
Doug

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The journal was probably worn that much to start with. Kim

gkent said:

You do all the clearancing AFTER the machine work. You have to be able to get the crank and a piston and rod in the block to know what's going to hit where. You clearance each cylinder seperately as necessary.

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You can use a wooden dowl to hold the rods in the center of the old bore before machine work to check clearances.
Some even machine spring loaded pins to do the same thing, just fancier and more adjustable.

On the 440s with the 4.25" stroker crank, I only needed to clearance the oil pump boss. Had clearance to all the bores. I guess i could have added extra clearance, but haven't had any problems. The 4.15" stroker crank with Mopar rods takes about the same (or more) amount of clearance as the 4.25" stroker crank with the GM rods.
I never compared the aftermarket I-Beam rods to the H-Beam rods to see if there is any difference in clearance (if the rod bolts extend farther down?) as the rod bolt heads are usually the closest to hitting.

Rods with studs/nuts typically stick out more then bolts and take more clearancing. A nut needs to have threads sticking out for proper torque which kills clearance.
We had a friend at one shop polish a extra .001 on a crank. It was a experiment, it took longer then it would take to turn a crank. The crank got so hot we ended up w considerably more clearance then we even wanted. By the time it cooled it was over .002 off! It also had a tendency to take more off the middle. You could compensate to some degree. We did run that crank a couple races..but generally speaking everyone is correct. Lol. Its not a good idea! Make it pretty and stop.

451Mopar said:

You can use a wooden dowl to hold the rods in the center of the old bore before machine work to check clearances.

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Curiousyellow71 said:

….It also had a tendency to take more off the middle.

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This. It kinda dishes from radius to radius.