Heads in the shop. To Mill or not to Mill?
#1
Heads in the shop. To Mill or not to Mill?
So I took the heads to the shop and the guy was very nice and willing to hook me up with a great price. He is going to remove the 2 sheered off exhaust bolts, clean the heads, install new valve seals and some LS6 springs I have. Also the guy is willing to mill the heads all for $200.
I need to let him know tomorrow how much to mill.
I am going with the Comp Cams Thumpr cam. Specs are:
Cam Style Hydraulic roller tappet
Basic Operating RPM Range 2,000-6,400
Intake Duration at 050 inch Lift 219
Exhaust Duration at 050 inch Lift 233
Duration at 050 inch Lift 219 int./233 exh.
Advertised Intake Duration 275
Advertised Exhaust Duration 295
Advertised Duration 275 int./290 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.553 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.536 in.
Valve Lift with Factory Rocker Arm Ratio 0.553 int./0.536 exh.
Lobe Separation (degrees) 109
I need to know what you guys recommend for how much to mill and what do I do for push rod length and do I need to worry about accessory alignment?
Engine Mods:
LM7, factory short block
Milled heads? 862 heads With LS6 Springs
Thumpr Cam
2" Primary LT headers, 3" exhaust with duel SLP Loudmouth mufflers
Edelbrock Performer RPM duel plane intake
Holley 750 cfm carb probably will do E85 conversion
MSD 6LS
I need to let him know tomorrow how much to mill.
I am going with the Comp Cams Thumpr cam. Specs are:
Cam Style Hydraulic roller tappet
Basic Operating RPM Range 2,000-6,400
Intake Duration at 050 inch Lift 219
Exhaust Duration at 050 inch Lift 233
Duration at 050 inch Lift 219 int./233 exh.
Advertised Intake Duration 275
Advertised Exhaust Duration 295
Advertised Duration 275 int./290 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.553 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.536 in.
Valve Lift with Factory Rocker Arm Ratio 0.553 int./0.536 exh.
Lobe Separation (degrees) 109
I need to know what you guys recommend for how much to mill and what do I do for push rod length and do I need to worry about accessory alignment?
Engine Mods:
LM7, factory short block
Milled heads? 862 heads With LS6 Springs
Thumpr Cam
2" Primary LT headers, 3" exhaust with duel SLP Loudmouth mufflers
Edelbrock Performer RPM duel plane intake
Holley 750 cfm carb probably will do E85 conversion
MSD 6LS
#4
http://www.youtube.com/watch?v=NeQ0jk-7Uzc
Thats what it will sound like, beautiful!
I am a Firefighter/Paramedic and I stopped by a local shop while I was on duty so the guy was very nice and said he would take care of me.
Thats what it will sound like, beautiful!
I am a Firefighter/Paramedic and I stopped by a local shop while I was on duty so the guy was very nice and said he would take care of me.
#6
This cam is Comps 2nd recommended cam for my application. I don't want crazy power. This cam works great for a carb application. Also the cam works with LS6 springs which I already have. And it will work with a stock stall. I am looking for around 400hp so this will be right there.
#7
http://www.youtube.com/watch?v=NeQ0jk-7Uzc
Thats what it will sound like, beautiful!
I am a Firefighter/Paramedic and I stopped by a local shop while I was on duty so the guy was very nice and said he would take care of me.
Thats what it will sound like, beautiful!
I am a Firefighter/Paramedic and I stopped by a local shop while I was on duty so the guy was very nice and said he would take care of me.
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#14
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I posted in your other thread in the truck forum. You're not gonna get 11:1 with those stock dished pistons. With flattop pistons, yeah. But, you listed the short block as being factory stock. The 5.3 heads are already at 61cc compression chambers. You can't mill them too much without running into piston to valve clearance problems. Generally, 59cc chambers are about as far as you want to go, maybe 58cc at most. The rule of thumb is 1cc for every .006" milled. The most I would personally mill is .015". At least that cam you listed has modest lift. Unless you change pistons, you are going to be at about 10:1.
#15
I posted in your other thread in the truck forum. You're not gonna get 11:1 with those stock dished pistons. With flattop pistons, yeah. But, you listed the short block as being factory stock. The 5.3 heads are already at 61cc compression chambers. You can't mill them too much without running into piston to valve clearance problems. Generally, 59cc chambers are about as far as you want to go, maybe 58cc at most. The rule of thumb is 1cc for every .006" milled. The most I would personally mill is .015". At least that cam you listed has modest lift. Unless you change pistons, you are going to be at about 10:1.
#17
Not to jack this thread but I have a L33 but do not have the 799 heads that it came with...I have a set of 853 heads that have to be milled to eliminate some surface scars.
How much would you remove ?? Stockish daily driver with a tune.
How much would you remove ?? Stockish daily driver with a tune.