l92 Pistons in a lQ4
#1
l92 Pistons in a lQ4
Hello all,
I searched and can't seem to find the answer. I have a 2002 LQ4 and would like to upgrade the rods and pistons. Can I run rectangle port valve reliefs with 317 heads?
Thanks for the help!
Bill
I searched and can't seem to find the answer. I have a 2002 LQ4 and would like to upgrade the rods and pistons. Can I run rectangle port valve reliefs with 317 heads?
Thanks for the help!
Bill
#4
#9
TECH Fanatic
L92/L99 pistons have a relief for the Exhaust Valve, Not the Intake Valve. The only reason for the relief was for VVT. LS3 pistons have no reliefs.
I don't see why you couldn't run 317's with L92 pistons unless your cam is pretty radical & the PTV clearance is getting close.....In that case you would need to fly cut just about any GM production piston.
I don't see why you couldn't run 317's with L92 pistons unless your cam is pretty radical & the PTV clearance is getting close.....In that case you would need to fly cut just about any GM production piston.
#10
11 Second Club
iTrader: (2)
As mentioned; apparently the reliefs are for the VVT exhaust clearance and not the intake as I had thought
Most LS3 guys can cam with a 230-232 @.050" intake lobe and still clear the 2.165" valves with the factory "no reliefs" pistons
Using the 2.0" valved 317 head castings you should be good as well if keeping the intake lobe around the 230-ish
#11
Thanks for all the replies. It makes sense if I use a cam that doesn't require reliefs that it won't matter.
another question.
I thought I read somewhere the older short 6.0 cranks are weaker than the gen 4s. Is this true?
another question.
I thought I read somewhere the older short 6.0 cranks are weaker than the gen 4s. Is this true?