Head gasket question
11-12-2016, 09:43 AM
#1
TECH Apprentice
Thread Starter
Head gasket question Will be putting on new heads. Nitrous 5.3 799 heads milled.020.
Motor is sbe. Curious if I will have PTV issues with 233/239 600 lift cam and .040 or .030 head gasket thickness. Would like to get as much compression as I can.
Motor is sbe. Curious if I will have PTV issues with 233/239 600 lift cam and .040 or .030 head gasket thickness. Would like to get as much compression as I can.
11-16-2016, 08:48 AM
#2
The only way to know for sure is to measure.
__________________
Aaron @ Scoggin Dickey Parts Center
Email:Aaron387@sdparts.com
Phone: 1-800-456-0211 Ext: 324
Aaron @ Scoggin Dickey Parts Center
Email:Aaron387@sdparts.com
Phone: 1-800-456-0211 Ext: 324
11-16-2016, 02:13 PM
#3
(What he said)
But at least you can eliminate options that likely won't work.
.030 gasket thickness is going to put your head too close to the piston. Usually you are somewhere around 0 - .005" out of the hole and a .040 gasket even is pushing it a bit. .030" and you would likely have pistons smacking the head when they rock in the bore.
Is this a dished piston 5.3? That would give you little more clearance. Is this an aluminum or iron block?
I am putting together a LS2(refreshed SBE) and went with the Fel-Pro .041 gaskets as I figured with my ~.006 OOH average and the expansion of the aluminum block, I'll have around .035" quench and that will expand a bit as the engine warms up. I'm just not going to take it straight to 7500RPM when it is cold.
As far as the cam goes, with .600 lift, you are probably fine but it's more about timing than lift really. Acceptable PTV is like .080 - .100. That's a small distance. So depending on when the valves are open and where the piston is, theoretically you could have a .300" lift cam with whacky timing/duration and still slam your valves. This is why it is important to put it together and check.
Short answer: I'd get the .040 or .041 gaskets, put the heads on, then measure.
Link to the process:
http://www.racingheadservice.com/rhs...earance-guide/
But at least you can eliminate options that likely won't work.
.030 gasket thickness is going to put your head too close to the piston. Usually you are somewhere around 0 - .005" out of the hole and a .040 gasket even is pushing it a bit. .030" and you would likely have pistons smacking the head when they rock in the bore.
Is this a dished piston 5.3? That would give you little more clearance. Is this an aluminum or iron block?
I am putting together a LS2(refreshed SBE) and went with the Fel-Pro .041 gaskets as I figured with my ~.006 OOH average and the expansion of the aluminum block, I'll have around .035" quench and that will expand a bit as the engine warms up. I'm just not going to take it straight to 7500RPM when it is cold.
As far as the cam goes, with .600 lift, you are probably fine but it's more about timing than lift really. Acceptable PTV is like .080 - .100. That's a small distance. So depending on when the valves are open and where the piston is, theoretically you could have a .300" lift cam with whacky timing/duration and still slam your valves. This is why it is important to put it together and check.
Short answer: I'd get the .040 or .041 gaskets, put the heads on, then measure.
Link to the process:
http://www.racingheadservice.com/rhs...earance-guide/