Rb20 Piston To Valve Clearance

[Psymon]

How much lift is it possible to have on an RB20 camshaft before there will be piston to valve clearance issues?

I have a 2nd hand head i'd like to put on my engine with aftermarket cams in it and they seem to have quite a bit more lift than standard cams. I don't want to put it on and crank it over only to end up with bend valves!

Edit: probably should have said that they're standard pistons!

Edited November 24, 2008 by Psymon

[Psymon]

Anyone?

[grandmasterb]

Im running HKS 264's with 9.3 lift with stock springs and there are no issues but have not wound much boost in yet.

Having said that after looking at the clearances i would say that 9.3-9.4 would be the most you could get away with prior to upgrading valve springs. Others will tell you to replace them anyway to be safe but for me it was a matter of $$$'s and curiosity to see if 9.3 was too much.

At the end of the day another RB20 is only $500 which is roughly the same for valve springs and i dont plan on running more than 1.2-1.3bar so will see what happens

[Psymon]

Well that seems to be the same lift as these cams have so it should be good! The valve springs are upgraded so shouldn't be a problem there.

I just wanted to make sure that the extra lift over factory wouldn't cause valves to start hitting pistons!