bigbrdf250

iTrader: (2)

So here's the deal, I supposedly have a real set of z06 243 heads with a lingenfelter stage 1 port and polish job. If they indeed have the sodium/hollow stems that means the valves are a bit longer but don't remember if its the exhaust or intake though??

Well my tuner/shop found a bad lifter and the valves hitting the piston I don't know which valve though. Sent the heads to the machine shop and the machine shop said the valves are too long!! They haven't suggested a fix yet but had mentioned about new valves or adjustable rockers, which means different valve covers or spacers and more money!!

I would rather stick to regular rockers than adjustable for the ease of things.

Comp cams 244/248 620 650
Dome top pistons

I guess what I'm asking/saying is if this is a common problem or have the heads been milled to much or not enough or what?? I'm not to familiar with the ls motor or how things work. I have a high compression of 12.4 for all I know. If there's any info that I missed please ask, I'm expecting a call tomorrow and would like to know some type of knowledge when I talk to them.

buddhaz06

iTrader: (8)

That's a big cam with domed pistons. My 638/624 with 243's and 2.08/1.60 valves made very tiny valve reliefs. That's on stock flat tops.

I'm not sure on the valve thing. Idk how the valves are too long. Are they installed already and been ran Like that?

bigbrdf250

iTrader: (2)

It has been ran like that before, I'm just going off what they are telling me.

therabidweasel

iTrader: (5)

So these threads really belong in internal engine, I think youd get more replies. Agree w buddahz. Are they saying they cant get a wipe pattern or are the just saying interference? I believe both easily with that cam.

Not sure on cutting reliefs in domes, just seems weird.

s346k

iTrader: (4)

i'd guess they are comparing the ls6 valve to an ls1 valve? the stock ls6 valves are not "too long", they are simply longer than ls1 valves. the same pushrod is used because the ls6 cams have a base circle that is 50 thou smaller in diameter. how much relief in the dome pistons? 4cc?

i'd try to get some concrete info on what valves are in the head. if they are indeed stock valves, i'd take those heads to a shop that knows wtf they are talking about.

i think that cam would have ptv issues on a stock head ls1 engine, even with the correct setup. both the intake and exhaust durations are huge.