JPH

iTrader: (2)

For anyone who cares, I degreed in and mocked up a motor this am for a customer and here are some ptv results fwiw.

2001 LS1 block
AFR 205 heas (unmilled)
-.007 deck clearance
3.930/.040 cometic
235/242 .621/.610 111+1 (LSL/XER)
cam in @111.25 ICL and 31* @.050 IVO and 6.5* .006 IVO
Checked with solid lifter/soft springs and stock rockers!

PTV clearance= .082 intake .151 exhaust

Hope this helps anyone, Joe

vettenuts

iTrader: (4)

Interesting. I recently read that contrary to popular belief, the AFR heads have more valve drop than TFS.

JPH

iTrader: (2)

I hear you. I didn't check that, but maybe next time I will though. Most people DON'T know how to check PTV correctly anyways from what I see. Heres another one for you.

2002 LS1
Stk Heads
Stk GM Head gaskets
Std. Deck (-.006 to -.008)
Crane 236/242 .600/.609 110+2 (HR5/HR5 Lobes)
Cam RETARDED 2.5* 110.5 ICL (for livable ptv, A4 car) needs cut imo.

PTV results= .041 intake w/cam installed straight up
.052+ intake, & can't remember on exhaust, but was ok .100+?

JPH

iTrader: (2)

I will post up some Crane LS1 "quick lift" rocker cam timing results, compared to a stock LS1 rocker also. Lets just say, PTV is on issue when switch from stk rockers to a Crane? (depending on cam design) lol

S10xGN

iTrader: (11)

I must be one of them. I have 'about' this same setup, a stock '03 350HP Corvette longblock with 241 heads and a Torquer V2 cam. I checked my PTV using a spring light enough to push down by hand, yet not collapse the lifter. Straight up, I had 0.200" and 0.190" on a cam with 0.595" and 0.598" lift. I checked it 10° either side of straight up and saw small (negative) changes. maybe on the order of 0.015" or less.

To me, this is a worst-case scenario with the lifter innards fully extended and pushing the valve stem into contact with the piston. What other way is there to do this?

Russ

vsocks1

iTrader: (6)

OEM LS6 block with TFS 215's milled to 60cc with 232/236 .595/.578 113+3 (installed 110 ICL) At 11 ATDC we had about 0.040-0.045 on intake....decided to flycut intake side 0.090 for sufficient clearance!

SweetS10V8

iTrader: (4)

I did mine with a checking spring, solid lifter, stock rocker, dial indicator, and an adjustable pushrod. L92 heads, milled .030" on an LQ9 short block.

Its a Comp LSR 219/235 .607/.621 113 +4, I paid extra for Comp to Adcole it for me. So I know exactly how its ground.

I had .090" on the intake and .085" on the exhaust. Im glad I didnt mill them anymore!

00SS6spd

iTrader: (3)

Please do, I was doing some research on them and I'm very interested in seeing how the "Quick Lift" design affects PTV. Especially since I'm strongly considering purchasing a set of them in 1.7 ratio for my car, with a setup that I'm wary to push the clearance limits of much farther.

Beaflag VonRathburg

iTrader: (176)

I'm sure you could call or PM Tony Mamo and ask him about the valve drop.

JPH

iTrader: (2)

Will do.

SweetS10V8

iTrader: (4)

I never understood "quick lift". Excuse my ignorance...

Why wouldnt you just get a cam designed with fast ramp rates? It makes it sound like "quick lift" rockers are made to help slow ramped stock camshafts.

What happens whey you put quick lift on a cam with a agressive ramp?

JPH

iTrader: (2)

The motor really like it and the intake opens about 4-6* sooner!

SweetS10V8

iTrader: (4)

So get a cam that opens 4 degrees soon? What happens when you have a cam with an agressive lobe?

Beaflag VonRathburg

iTrader: (176)

^ I'm sure you could run into some valve train instability issues with an inadequate spring. You also have to be aware of your PTV clearance like it was previously mentioned.

00SS6spd

iTrader: (3)

Any update?

JPH

iTrader: (2)

I haven't forgotten about the rocker/cam setup. I do it soon.

JPH

iTrader: (2)

True, but the rocker will help the cam act bigger and what not! As far as using a cam with a more aggerssive lobe, you can run into some unstable valvetrain issuses also.