Whos runing 243s milled on a LQ9>?
10-30-2013, 11:14 AM
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Whos runing 243s milled on a LQ9>?
ok, thought it would be best to start a new thread about the heads 243s milled that Im thinking about putting on my LQ9. I could always mill my 317s .030 I thought but then I will be just a tad about what some 243s would do.
So I want every hp per cube out of this engine. NA, that said, would I be okay to purchase some 243s and what do I need to mill off of them?
I run 93 octane. But I want this engine to be atleast a 11.1 motor.
So I want every hp per cube out of this engine. NA, that said, would I be okay to purchase some 243s and what do I need to mill off of them?
I run 93 octane. But I want this engine to be atleast a 11.1 motor.
10-30-2013, 06:53 PM
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and how would that compression work my Lunati Camshaft:
Advertised Duration (Int/Exh): 272/278
Duration @ .050 (Int/Exh): 222/228
Gross Valve Lift (Int/Exh): .567"/.567"
LSA/ICL: 113/109
Valve Lash (Int/Exh): Hyd/Hyd
RPM Range: 2000-6600
10-31-2013, 12:16 AM
#6
.010 milled 317 heads and a .040 gasket will be around 10.6 ish and a dynamic compression of 8.45 ish with your cam of choice. Which about the max you want to run on pump gas.
No need to go with 243 heads because you would end up with to much cylinder pressure, you would need a larger cam to bleed some of that off.
No need to go with 243 heads because you would end up with to much cylinder pressure, you would need a larger cam to bleed some of that off.
Last edited by jmgak47; 10-31-2013 at 12:58 AM.
10-31-2013, 12:54 AM
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.010 milled 817 heads and a .040 gasket will be around 10.6 ish and a dynamic compression of 8.45 ish with your cam of choice. Which about the max you want to run on pump gas.
No need to go with 243 heads because you would end up with to much cylinder pressure, you would need a larger cam to bleed some of that off.
No need to go with 243 heads because you would end up with to much cylinder pressure, you would need a larger cam to bleed some of that off.
save my coin, for the ls7 lifters, chain, springs, TBSS intake and 102mm tb. Trying to get my best bang.
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10-31-2013, 01:03 AM
#8
Yeah 317... my bad. Its been a long day.
The cam will be fine, just you don't need to mill them .020 because you will not be able to run the timing you could with them just milled .010 Basically it will be more prone to detonation.
But with .020 milled heads and .040 gaskets you will be around 10.87 compression and a dynamic compression of 8.6 You could run 93 pump gas @ that compression but your really pushing it and would be no better of power wise then if you just milled the heads .010
The cam will be fine, just you don't need to mill them .020 because you will not be able to run the timing you could with them just milled .010 Basically it will be more prone to detonation.
But with .020 milled heads and .040 gaskets you will be around 10.87 compression and a dynamic compression of 8.6 You could run 93 pump gas @ that compression but your really pushing it and would be no better of power wise then if you just milled the heads .010
10-31-2013, 01:07 AM
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Yeah 317... my bad. Its been a long day.
The cam will be fine, just you don't need to mill them .020 because you will not be able to run the timing you could with them just milled .010 Basically it will be more prone to detonation.
But with .020 milled heads and .040 gaskets you will be around 10.87 compression and a dynamic compression of 8.6 You could run 93 pump gas @ that compression but your really pushing it and would be no better of power wise then if you just milled the heads .010
The cam will be fine, just you don't need to mill them .020 because you will not be able to run the timing you could with them just milled .010 Basically it will be more prone to detonation.
But with .020 milled heads and .040 gaskets you will be around 10.87 compression and a dynamic compression of 8.6 You could run 93 pump gas @ that compression but your really pushing it and would be no better of power wise then if you just milled the heads .010
My tuner has a good bit of timing in her right now... so dont want to compromise that...
10-31-2013, 01:13 AM
#10
That is another option!
Yes the .040 gasket is what I would run, it will give you a good quench.
You would be sitting @ 10.36 ish compression with a dynamic compression of 8.2 ish, it is on the safe side for 93 octane but not the crazy safe side lol Your still optimizing your setup.
Yes the .040 gasket is what I would run, it will give you a good quench.
You would be sitting @ 10.36 ish compression with a dynamic compression of 8.2 ish, it is on the safe side for 93 octane but not the crazy safe side lol Your still optimizing your setup.