853 casting heads do they fit 5.3
11-30-2011, 11:12 AM
#22
the problems with running other heads on the 5.3/4.8 is that the combustion chambers are larger on the other heads. you'd have to mill the others in order to get the same CR as the 5.3's
03regcab sierra,
I don't think running 2.00" valves on a NA setup will give me gains where I want them. I've been looking at the Mach index of different valve sizes... with the stock cam with .466 lift, the bigger valves would help (1.89 is .58 @ 6k rpm, and the 2.00 is .55 @ 6k) since an index greater than .5 is considered restrictive. When I install a higher lift cam (.551), the index drops from .49 to .46 by going larger which is going to kill my bottom end since lower than .5 doesn't produce the velocity needed for volumetric efficiency.
Sure, I'd be able to get higher revs, but this is a daily driver that rarely sees +5k regardless or redline.
Turbo or SC added to the mix completely changes things.
I think I'm going to stick with my wimpy 1.89's and take the power under the curve.
03regcab sierra,
I don't think running 2.00" valves on a NA setup will give me gains where I want them. I've been looking at the Mach index of different valve sizes... with the stock cam with .466 lift, the bigger valves would help (1.89 is .58 @ 6k rpm, and the 2.00 is .55 @ 6k) since an index greater than .5 is considered restrictive. When I install a higher lift cam (.551), the index drops from .49 to .46 by going larger which is going to kill my bottom end since lower than .5 doesn't produce the velocity needed for volumetric efficiency.
Sure, I'd be able to get higher revs, but this is a daily driver that rarely sees +5k regardless or redline.
Turbo or SC added to the mix completely changes things.
I think I'm going to stick with my wimpy 1.89's and take the power under the curve.
01-25-2012, 06:30 PM
#25
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tru spent21. so what kind of options do i have for this. is there gaskets to compensate for this? im using the stock intake for now but ill be going with the fast 102mm to go with the 102mm tb i already have. would it be the same for this. any input appreciated.
01-25-2012, 07:34 PM
#26
the problems with running other heads on the 5.3/4.8 is that the combustion chambers are larger on the other heads. you'd have to mill the others in order to get the same CR as the 5.3's
03regcab sierra,
I don't think running 2.00" valves on a NA setup will give me gains where I want them. I've been looking at the Mach index of different valve sizes... with the stock cam with .466 lift, the bigger valves would help (1.89 is .58 @ 6k rpm, and the 2.00 is .55 @ 6k) since an index greater than .5 is considered restrictive. When I install a higher lift cam (.551), the index drops from .49 to .46 by going larger which is going to kill my bottom end since lower than .5 doesn't produce the velocity needed for volumetric efficiency.
Sure, I'd be able to get higher revs, but this is a daily driver that rarely sees +5k regardless or redline.
Turbo or SC added to the mix completely changes things.
I think I'm going to stick with my wimpy 1.89's and take the power under the curve.
03regcab sierra,
I don't think running 2.00" valves on a NA setup will give me gains where I want them. I've been looking at the Mach index of different valve sizes... with the stock cam with .466 lift, the bigger valves would help (1.89 is .58 @ 6k rpm, and the 2.00 is .55 @ 6k) since an index greater than .5 is considered restrictive. When I install a higher lift cam (.551), the index drops from .49 to .46 by going larger which is going to kill my bottom end since lower than .5 doesn't produce the velocity needed for volumetric efficiency.
Sure, I'd be able to get higher revs, but this is a daily driver that rarely sees +5k regardless or redline.
Turbo or SC added to the mix completely changes things.
I think I'm going to stick with my wimpy 1.89's and take the power under the curve.
01-28-2012, 01:16 AM
#28
It takes about .005" milling of the block deck to remove 1cc of volume. It takes .007" milling to remove 1cc from an LS1 head
You have a stock 66cc chamber and you want to get down to 63cc
66-63 = 3. You have to remove 3cc's
.007 x 3 = .021. So to get your 66cc chambers down to 63cc you'd have to mill ~.021.
You can also do the reverse, say you want to mill a head .030 to figure out how many CC's that removes you take .030 / .007 = ~ 4.28. Milling a stock 5.7 head .030 puts your chamber at ~ 62.
01-28-2012, 10:49 PM
#30
I can't remember who posted it, but I got the following off the forum a while back...
It takes about .005" milling of the block deck to remove 1cc of volume. It takes .007" milling to remove 1cc from an LS1 head
You have a stock 66cc chamber and you want to get down to 63cc
66-63 = 3. You have to remove 3cc's
.007 x 3 = .021. So to get your 66cc chambers down to 63cc you'd have to mill ~.021.
You can also do the reverse, say you want to mill a head .030 to figure out how many CC's that removes you take .030 / .007 = ~ 4.28. Milling a stock 5.7 head .030 puts your chamber at ~ 62.
It takes about .005" milling of the block deck to remove 1cc of volume. It takes .007" milling to remove 1cc from an LS1 head
You have a stock 66cc chamber and you want to get down to 63cc
66-63 = 3. You have to remove 3cc's
.007 x 3 = .021. So to get your 66cc chambers down to 63cc you'd have to mill ~.021.
You can also do the reverse, say you want to mill a head .030 to figure out how many CC's that removes you take .030 / .007 = ~ 4.28. Milling a stock 5.7 head .030 puts your chamber at ~ 62.
https://www.performancetrucks.net/fo...g-info-434396/
I am not sure who came up with the Block being milled .005 removes 1cc of volume because bore Size and piston design would greatly affect that.
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