SBC crank clearance?
 

am going to redo an old SBC which had a Lot of bearing clearance [3 on R & 3.5 on M, 50 wt oil 90lbs PSI OLD]
crank is std - clearance. I want to turn it 10-10 and start new. what is the best clearance for a race engine, good rods, 7K max. no more high PSI or heavy oil. Cleavite P bearings
Thanks Rod in AZ

Re: SBC crank clearance?
 

Good morning Rod and to all,
I'm pretty confident if you can get your Main and Rod clearance's between .002 to .0025 you should be in a good zone. Running to 7500 rpm with 5/ 30 wt. oil 60 to 70 lbs. of oil pressure will also be safe.
Have a good day, also have the crank magged for cracks before having any work done is also a good idea.

Respectfully,
Henry Kunz 1534 H/SA

Re: SBC crank clearance?
 

clevite H series bearings r a good thing too. be aware the H series rod bearings r marked for upper/lower orintation.

Re: SBC crank clearance?
 

What Henry said is spot on, that’s exactly what I shoot
for clearance and pressure wise, things are happy there
and will give good performance and longevity!

Re: SBC crank clearance?
 

I like 0.002" on the rods, and 0.0025" on the mains, and I prefer the King bearings. If you go higher than that on clearance, you probably need to use thicker oil, ie. 20W50.

Re: SBC crank clearance?
 

thanks all for the help. funny to think back on how ideas used to be. you can just imagine the cam/dist gear milling away trying to turn an oil pump shimmed to pump 90 lbs.!!
Rod in AZ