Box Stock

Crankshaft end play

Think about it this way, if you have say .025 endplay with the engine cold, then ideally once the engine is up to temp, the endplay should be right in the range where most of us are saying we would want to see it at. No, i do not think .030" end play when the engine is hot is acceptible, i meant that as a max and with a cold engine. i personally like to see .008" or so when the engine is hot, i set endplay according to what i see when the engine is at temp, since that is where it will be spending the most time running and that is where it matters the most. I could care less what the endplay is on a cold engine as long as it is not excessively loose, since the engine spends relatively little time cold when we are on the racetrack.
 
Has anyone checked the end play on a cold vs warm motor ? There are a lot of variables here . As with valve lash, are we sure the clearance shrinks ? or does it grow ?
 
Clearance shrinks from a cold engine to a warm/hot engine, as the steel expands, that has been my experience
 
Weddle Racing said:
Clearance shrinks from a cold engine to a warm/hot engine, as the steel expands, that has been my experience
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When dealing with so many variables of the alloy materials (Like when Valve Lash grows with heat) I wasn't sure ...On "Kart Tech" I just posted a video showing "Crank walk" at the flywheel . I don't know how to post vids on Bob's...
 
Kart43 said:
.010" is is where you should shoot for. Weddle check your alarm clock .030"???? You should shoot for .004 to .005" rod side clearance and enough crank end play to to prevent binding between the bearings when at temp.

This will only work for the SA and opens as your BSP will not allow modifications. It has been a long time since I did this and don't intend to repeat it, but it is a very enlightening experiment.

Assemble an old block with side cover, gasket and only the crankshaft installed, make certain everything turns as freely as you can make it. spin the crank a few times note how easy it turns and how long it spins. Place this assembly in an oven at 350* remove it and recheck the spin of the crankshaft. I found that the bearing bores pinched down on the steel bearings enough to bind the races against the balls. We actually had to right a rule specify that the bearings were not allowed to be pulled out of the bores by hand. Builders were sanding the blocks out so far the bearings would fall in and out.


This is not stated to tell you it is permissible, you better check your rules, and the rule writers need to specify in regard to this. Don't start bashing the clone or the rules it is a simple fact this would be beneficial in any bearing captured in Aluminum in any brand of eng
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Does anyone know if crankshaft end play can cause a knocking noise? I've recently built a predator engine with a billet flywheel, rod, cam, and springs and while running noticed a knocking noise. The crankshaft seems to have too much end play to the point where I can pull it and it will make a clinching noise. I disassembled it and the rod bears have no extra wear on them and the rod is in good condition still. Any ideas?
 
You got good info on your other post .
Pulling slowly by hand they can make a noise when the cam rolls past the lifter .
The springs take up the lash in the cam gears . There are several posts about this same issue.
 
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