Crankshaft Counterweight Clearance

[stevec]

I discoverd another small problem with the on-centers. I am using a SCAT 3.652 steel crankshaft. I placed the crank in the motor so I could notch the clyinder bores. I noticed that both the front and rear counterweights were very very close to the block surface. I stuck a feeler guage in there and got about .008. This is way too tight. The endplay alone will cause interference.

I have another crankshaft (BRC) 3.59 stroke so I get it out and measure the counterweight thickness. Here it what I got:

Scat BRC Diff.
1.145 1.100 Front .045
1.210 1.160 Rear .050

Looks like each crank grinder finished the counterweights a little different. I dont think using the SCAT crank in an off-center would cause any problems because it doesnot have the cross bolted front and rear caps.

I think the easiest way to fix the problem is to send the crank off and have the counterweights clearenced. I looked at notching the block and dont think this is the best way to solve this problem.

Oh well,if its not one thing it is something else.


Thanks

Steve C

 

[KendallF]

I have an on-center block with a relocated wet sump pickup by #1 cap..the front counterweight basically needs to be shaved at an angle to clear it. Luckily, the crank I ended up with had been done like this already. Aren't all these quirks fun?!