f-bodman

I've been told I can't use a hydraulic lifter to check PTV clearance and since that's what I have under my half installed heads I figured this might work.

Can I just check cam lobe lift at 8* multiply it by 1.7 and then subtract that from my valve drop at 8* to get my clearance?

How accurate would this be? I was pretty convinced after degreeing in my cam last night and "attempting" to install the rockers with the checker springs I have on the #1 cylinder right now that it wasn't gonna fit.

So far I have this, at TDC my valve drop is .125, lobe lift is .064... So .064x1.7=.109 and so I would have .016 clearance at TDC right? At 8* ATDC I have .148 valve drop and .093 lobe lift and that comes out to .148-.093x1.7= -.010

What do you guys think is this pretty accurate way to check or is there something I'm not taking into consideration? Looks like flycutting .100 to me

WS6FirebirdTA00

iTrader: (33)

are the heads milled at all? this is the F13 cam? it should fit with no problems at all

f-bodman

Yup, F13 on a 114, problem is the heads have 2.04 intake valves and I only have .125 valve drop a TDC. And no the heads are unmilled.

WS6FirebirdTA00

iTrader: (33)

ok must be the larger vavles then, most guys have no issues at all on 2.02 vavles and unmilled. thats strange though still i would think it would have some clearance, did you install the cam dot to dot or with any advance?

f-bodman

I installed it dot to dot, but it does have 4 degrees advanced timing ground in. I think with that and the bigger valves it's causing me problems. Thanks for the responses WS6firebirdTA00

So no one else has an opinion on checking PTV clearance this way, c'mon fellas I know this isn't one of the important threads like "what cam to get" and "how much power will this combo make" but c'mon

f-bodman

Also I've been told that Futral cams have a bigger base circle?? If that's true wouldn't that cut down on my clearances even further?

WS6FirebirdTA00

iTrader: (33)

lots of guys try to clay it, have you tried that and then turning hte motor over by hand?

f-bodman

The motor won't turn over by hand, well it will but it hangs up around TDC , that's what made me realize I might have clearance problems to begin with. I could clay it but it would just cut it in half

WS6FirebirdTA00

iTrader: (33)

damn that really blows, did u have the head gaskets on when doing this? what kind are they?

f-bodman

I have the stock graphite gaskets on, the worst part is I haven't done the torque to yield part yet I just have new GM bolts torqued to ~22lb. I think after I pull the heads off I might get some MLS gaskets. Well I've got a flycutting kit on the way from TSP right now, wish me luck.

WS6FirebirdTA00

iTrader: (33)

let me know how that goes i may have to do it in about a year or so