SR20DET/VET bearing clearances

Hi, I’ve been building a uk 200SX/S14 for a few years and and put a p11 vvl cylinder head on it.

im wondering what the best bearing clearances would be to use on a higher rpm higher powered engine. I’m guessing the factory clearances are no good.

I searched previous posts and found a lot of info on evo clearances are they pretty similar as far as clearance goes? Looser on the mains and tighter on the big ends 0.0025 and 0.0020 I’ve seen mentioned.

ps I am asking this info too late and am looking to repair an issue I run into after my car started knocking after a few pulls on the dyno. But looking to fix my mistake....

John

Hey,

Factory clearances are very tight on these, but the rule of thumb of 0.001" per inch of diameter on the Main and Rod Bearing clearance always gave me good results on these engines, with ACL Race bearings.

Thank you for that Frank, time to pull it down, see where I’ve gone wrong.

I think the first place to start would be to find out what went wrong as it may not be the result of your clearances. The big ends I set to the same as our 4G63 - 0.002". The mains can be between 0.002-0.0025" since the block is alloy and tends to grown more as it heats up than a cast iron block.

Thanks for the reply, I can only check clearances and clean the components as much as possible.

#2 big end spun, the rod has seen a lot of heat, so will need replaced. I’ll have the crank repaired and Attempt to do it properly this time.

Not too sure whether it’s even relevant anymore but I plastigauged the crank with the shells from the good rods and even fitted new bearings to the damaged one just to get an idea of what size I was at.

0.063mm or about 0.0025” on #3 and #2 (the damaged journal)

the main bearings were pretty chewed up too maybe just from the big ends, or possible they failed causing the big end to spin.