Box Stock

Crank end play

J

jibco520

Member
Let's say you have way to much crank end play - say .050 or so. How do you know which end ( or even both? ) to shim to keep rod big end happy?
 
Excellent question, I have often pondered this and am looking forward to answers. Doing it improperly influences reliability and internal friction. Lacking a way to measure it I always "assumed" that the variation would be self corrected by the side play in the rod.
 
Last edited:
Did you check the cam side clearance.You need to know this before you to start making big changes or you may end up with tight or no cam side clearance.
 
Last edited:
You could narrow down the cause of by switching out the crankshaft and remeasure clearance then switch out side cover measure again and it'll be one of the three, crank block or side cover
 
I think most respondents are missing the point of this post. I believe he is asking how to be certain that the crank pin is centered in the bore.
 
Post #5 adrresses it somewhat .
Personally not worth the effort .
One way . Cut two disc's too fit cylinder with a small hole in the center assemble block and crank
with a cut side cover , too hold crank and allow access inside .
Slip disc in perectly perpendilular to the bore .
one top one bottom .
Shin a laser through the holes and see where it lands on the crank pin .
 
It's just a theoretical question really. All I can think of is using a cutaway side cover and try to wiggle rod on crank a bit when you think you have end play of crank and cam close. Seem logical?
 
jibco520 said:
It's just a theoretical question really. All I can think of is using a cutaway side cover and try to wiggle rod on crank a bit when you think you have end play of crank and cam close. Seem logical?
Click to expand...
thats not how to check end play, at least not the way i been doing it for 30 years now, you dont WIGGLE the rod at all, you have to put the engine all together and use dial indicators to see how much you can push/pull the crankshaft back and forth, if it is too much, use shims, not enough, use thicker sidecover gasket, thats how i would do it but im sure there are other ways also.
 
Put Dykem on the PTO side of the rod journal and shim from the PTO side. Once you get your end play where you want it with everything tight, disassemble it and see if the Dykem is rubbed off. If it is, move one shim at a time to the mag side and repeat the Dykem test. When you’re not rubbing the Dykem off you’re close enough to center of the bore.
 
I came u] with shimming end play as most do with rod only on crank and put it near TDC then rock it left and right and measure distance from side of small ends to cylinder wall. Good enough for me. Just to know its not all on 1 side for some reason. So with bevel on cam gear does it want to walk in or out?
 
You must log in or register to reply here.
Back
Top