Max boost on regular 4-bolt heads?
06-14-2008, 03:21 PM
#1
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Max boost on regular 4-bolt heads? On a proper forged setup, what would be the max boost you can run on a ported factory 4-bolt casting before you have to worry about head lifting?
06-14-2008, 04:58 PM
#5
Why dont you go with aftermarket Casting??? Budget build???
17-18psi IMO After that you'll have to worry big time.
Mighty mouse 20+psi with a litttle head lifting If I remember correctly maybe he will help.
Also Kp Ran 18psi with F1A 346ci without any lifting.
Hunter with His TT.
BTW all of them were running AFR 255 I really cant remember Anyone that ran 18+ psi with Factory casting.
Lots people say its all in the tune.
lol
17-18psi IMO After that you'll have to worry big time.
Mighty mouse 20+psi with a litttle head lifting If I remember correctly maybe he will help.
Also Kp Ran 18psi with F1A 346ci without any lifting.
Hunter with His TT.
BTW all of them were running AFR 255 I really cant remember Anyone that ran 18+ psi with Factory casting.
Lots people say its all in the tune.
lol
06-14-2008, 05:58 PM
#7
Why dont you go with aftermarket Casting??? Budget build???
17-18psi IMO After that you'll have to worry big time.
Mighty mouse 20+psi with a litttle head lifting If I remember correctly maybe he will help.
Also Kp Ran 18psi with F1A 346ci without any lifting.
Hunter with His TT.
BTW all of them were running AFR 255 I really cant remember Anyone that ran 18+ psi with Factory casting.
Lots people say its all in the tune.
lol
17-18psi IMO After that you'll have to worry big time.
Mighty mouse 20+psi with a litttle head lifting If I remember correctly maybe he will help.
Also Kp Ran 18psi with F1A 346ci without any lifting.
Hunter with His TT.
BTW all of them were running AFR 255 I really cant remember Anyone that ran 18+ psi with Factory casting.
Lots people say its all in the tune.
lol
18psi with the F1A and AFR heads and GM MLS gaskets would push some water here and there with the LS6 block, maybe a cupful, this LS2 block so far hasnt pushed any even with the F1A maxed out but I havent ran it in any good weather so its making a lot of power, I'll see what happens when it cools off out but so far the LS2 block seems to be holding a little better. Unfortunately I have no plans of a bigger blower or turbo so thats as fas as I can go
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06-14-2008, 07:15 PM
#8
9 Second Club
After pushing a little water....at what point would you be concerned about gasket integrity ?
Ive been logging system pressure in my header tank. I had a little rise last weekend, and lost a very small quantity of water, so Im sure I had leakage of some sort. Circa 17psi in the header tank.....Usually its 10-12psi on a warm day.
After my last run, water temps also rose to almost 220degF, which is some 20-25degF higher than normal.
At home, and back to some cooler weather and road use....system pressure remains at around 7-8psi, even with a few 3rd and 4th gear blasts down the road.
Ive been logging system pressure in my header tank. I had a little rise last weekend, and lost a very small quantity of water, so Im sure I had leakage of some sort. Circa 17psi in the header tank.....Usually its 10-12psi on a warm day.
After my last run, water temps also rose to almost 220degF, which is some 20-25degF higher than normal.
At home, and back to some cooler weather and road use....system pressure remains at around 7-8psi, even with a few 3rd and 4th gear blasts down the road.
06-14-2008, 08:21 PM
#10
After pushing a little water....at what point would you be concerned about gasket integrity ?
Ive been logging system pressure in my header tank. I had a little rise last weekend, and lost a very small quantity of water, so Im sure I had leakage of some sort. Circa 17psi in the header tank.....Usually its 10-12psi on a warm day.
After my last run, water temps also rose to almost 220degF, which is some 20-25degF higher than normal.
At home, and back to some cooler weather and road use....system pressure remains at around 7-8psi, even with a few 3rd and 4th gear blasts down the road.
Ive been logging system pressure in my header tank. I had a little rise last weekend, and lost a very small quantity of water, so Im sure I had leakage of some sort. Circa 17psi in the header tank.....Usually its 10-12psi on a warm day.
After my last run, water temps also rose to almost 220degF, which is some 20-25degF higher than normal.
At home, and back to some cooler weather and road use....system pressure remains at around 7-8psi, even with a few 3rd and 4th gear blasts down the road.
With the LS6 block, 5.7 GM MLS gaskets and small bore AFR 225 heads made it the longest for me.
06-15-2008, 03:33 AM
#11
9 Second Club
My cooling system is at its limit on a warm day even in slow moving traffic. My radiator is a decent size although perhaps still not big enough, but being totally blocked by the IC, which is only about 1.5-2" in front of it, is far from ideal.
As it is now, with 2 fans covering a fair amount of the core, and all 4 steam ports in use, on a warm day, temperature can remain in control during normal driving, and total stop traffic. But its just about doing it.
When I was racing at the weekend, I fitted the coldest stat I could due to the temperatures, but without proper forward motion airflow thru the rad, temperatures still remained higher than ideal.
Im presently on LS6 block ( in use for some 3+ years now, and second hand when I got it ) new 5 layer MLS and TFS 225cc heads ( large bore )
Last rebuild I did get the block machined. Limited ( ie. crap ) machinists here mean the deck is flat, but the smoothness was far from ideal
As it is now, with 2 fans covering a fair amount of the core, and all 4 steam ports in use, on a warm day, temperature can remain in control during normal driving, and total stop traffic. But its just about doing it.
When I was racing at the weekend, I fitted the coldest stat I could due to the temperatures, but without proper forward motion airflow thru the rad, temperatures still remained higher than ideal.
Im presently on LS6 block ( in use for some 3+ years now, and second hand when I got it ) new 5 layer MLS and TFS 225cc heads ( large bore )
Last rebuild I did get the block machined. Limited ( ie. crap ) machinists here mean the deck is flat, but the smoothness was far from ideal
06-15-2008, 12:57 PM
#12
My cooling system is at its limit on a warm day even in slow moving traffic. My radiator is a decent size although perhaps still not big enough, but being totally blocked by the IC, which is only about 1.5-2" in front of it, is far from ideal.
As it is now, with 2 fans covering a fair amount of the core, and all 4 steam ports in use, on a warm day, temperature can remain in control during normal driving, and total stop traffic. But its just about doing it.
When I was racing at the weekend, I fitted the coldest stat I could due to the temperatures, but without proper forward motion airflow thru the rad, temperatures still remained higher than ideal.
Im presently on LS6 block ( in use for some 3+ years now, and second hand when I got it ) new 5 layer MLS and TFS 225cc heads ( large bore )
Last rebuild I did get the block machined. Limited ( ie. crap ) machinists here mean the deck is flat, but the smoothness was far from ideal
As it is now, with 2 fans covering a fair amount of the core, and all 4 steam ports in use, on a warm day, temperature can remain in control during normal driving, and total stop traffic. But its just about doing it.
When I was racing at the weekend, I fitted the coldest stat I could due to the temperatures, but without proper forward motion airflow thru the rad, temperatures still remained higher than ideal.
Im presently on LS6 block ( in use for some 3+ years now, and second hand when I got it ) new 5 layer MLS and TFS 225cc heads ( large bore )
Last rebuild I did get the block machined. Limited ( ie. crap ) machinists here mean the deck is flat, but the smoothness was far from ideal
I would take rough and flat as opposed to warped and smooth.
