PTV Clearance Measuremet to Figure Out How Much To Mil Heads
09-09-2017, 07:10 PM
#21
ModSquad
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You need to take apart a hyd lifter and shim it up until it is solid, make sure it has no slop. then put the heads on with (NO ) head gasket. With a checker spring on 1 intake valve and 1 exhaust valve check the clearance 8-10 degrees before and after TDC. No rockers on any other valves. Just add the thickness of the head gasket for you results. 8-10 degrees before and after is where the valve is the closest to the piston.
09-13-2017, 10:53 AM
#22
FormerVendor
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EAP P/V Model Hi MJS, OK AND I suggest the CAM be +2 for Split Overlap.
FIRST, the Valve Drop :
E =.175"
I = .165"
SECOND, the HG of OEM = .051" AND "proud" piston deck of +.008".
RESULTS : EAP Model P/V Split Overlap
E = .128" @ 352*
I = .114" @ 368*
Lance
FIRST, the Valve Drop :
E =.175"
I = .165"
SECOND, the HG of OEM = .051" AND "proud" piston deck of +.008".
RESULTS : EAP Model P/V Split Overlap
E = .128" @ 352*
I = .114" @ 368*
Lance
09-13-2017, 03:50 PM
#23
Thanks for putting that together doing the math on that for me. I ended up getting a clearance of .083 intake and .108 exhaust after retrying. I talked two of the more popular head porting companies, one suggested based on my numbers I should just do a cleanup mil, and another recommended taking .020 off.
Pantera, based on the numbers you got, I have more room and can remove more off the heads.
Pantera, based on the numbers you got, I have more room and can remove more off the heads.
Last edited by mjs1012; 09-13-2017 at 03:56 PM.
09-14-2017, 10:12 AM
#24
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Valve Drop Measurement Hi MJS, you should CONFIRM my specifications as YOURS.
The first step would be to measure your valve drop and CONFIRM ?
The NEXT step is to confirm your cam timing as mine is +2* used for the EAP model.
YOUR .083" vs MY .114" is a difference of .031" ( ten hairs) AND with the 1* Cam Timing difference.
This EAP example IS very close to your measurement, a good "quick" test.
The good news is when you engine is up to temp, the P/V distance will increase.
Lance
The first step would be to measure your valve drop and CONFIRM ?
The NEXT step is to confirm your cam timing as mine is +2* used for the EAP model.
YOUR .083" vs MY .114" is a difference of .031" ( ten hairs) AND with the 1* Cam Timing difference.
This EAP example IS very close to your measurement, a good "quick" test.
The good news is when you engine is up to temp, the P/V distance will increase.
Lance
09-14-2017, 01:00 PM
#25
TECH Addict
Just so you know the dish on LQ4 pistons doesn't help with PTV since the valve will hit the outer high spot of piston.
Last edited by gagliano7; 09-15-2017 at 12:09 PM.