What comp. should I go with?
03-23-2007, 06:50 PM
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What comp. should I go with using TFS 225cc? I am taking my LS6 heads off and buying the TFS 225cc heads in 2wks. This is for a street car. My cam is a 244/248..612/615..112LSA. I was thinking of around 11.7. What do yall think? If I go with a stock GM LS2 gasket and a 67cc, will that be 11.75?. Or what cometic gasket?The motor is 4.060 bore and a 4 stroke. My pistons are flat top with -2cc. What spark plugs should I go with?
Last edited by jeremym; 03-25-2007 at 12:56 AM.
03-24-2007, 09:21 AM
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Originally Posted by jeremym
I am taking my LS6 heads off and buying the TFS 225cc heads in 2wks. This is for a street car. My cam is a 244/248..612/615..112LSA. I was thinking of around 11.7. What do yall think? If I go with a stock GM LS2 gasket and a 67cc, will that be 11.75?. The motor is 4.060 bore and a 4 stroke. My pistons are flat top with -2cc. What spark plugs should I go with?
11.2:1-11.7:1 give or take....
just stay out of the 12:1 area....... Texas heat and E85 gas...... no way would I do 12:1........ less compression means more timing at a point.
03-24-2007, 10:33 AM
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Originally Posted by Forteen3GT
11.2:1-11.7:1 give or take....
just stay out of the 12:1 area....... Texas heat and E85 gas...... no way would I do 12:1........ less compression means more timing at a point.
just stay out of the 12:1 area....... Texas heat and E85 gas...... no way would I do 12:1........ less compression means more timing at a point.
03-24-2007, 12:57 PM
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Originally Posted by jeremym
11.2 and 11.7 are a big diff. Which one would it be Mike? When is your car going to be ready?
either one is good. 11.7 aint bad and you will make more power... but with 11.2 you wont have issues with "bad" pump gas. but you know this.
I am going around 11.3:1 or so iirc. but this is up to the builders.
It is at the shop now. I went up there to discuss the nitrous setup and buy some convo pros. It will be on the street in 2 weeks or so. Waiting on Greg to finish the heads up. He has the valves and stuff.
Getting close to draggin that ***!
Look forward to running you on motor!
03-24-2007, 04:47 PM
#6
From the looks of things, you need to stay somewhat on the high side to keep DCR up. Another thing is the LS2 gaskets. There set-up for a 4" bore, not 4.060". You will probablly need to get Cometics in order to get the correct bore size/thickness. It'll also optimize your quench area. If it were me, I'd do:
70cc heads, .040" Cometics (4.080" gasket bore), advance the cam 2*. That'll give you 11.7 SCR and 8.5 DCR.
70cc heads, .040" Cometics (4.080" gasket bore), advance the cam 2*. That'll give you 11.7 SCR and 8.5 DCR.
03-25-2007, 12:41 AM
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Originally Posted by Beast96Z
From the looks of things, you need to stay somewhat on the high side to keep DCR up. Another thing is the LS2 gaskets. There set-up for a 4" bore, not 4.060". You will probablly need to get Cometics in order to get the correct bore size/thickness. It'll also optimize your quench area. If it were me, I'd do:
70cc heads, .040" Cometics (4.080" gasket bore), advance the cam 2*. That'll give you 11.7 SCR and 8.5 DCR.
70cc heads, .040" Cometics (4.080" gasket bore), advance the cam 2*. That'll give you 11.7 SCR and 8.5 DCR.
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03-25-2007, 12:58 AM
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Originally Posted by Beast96Z
From the looks of things, you need to stay somewhat on the high side to keep DCR up. Another thing is the LS2 gaskets. There set-up for a 4" bore, not 4.060". You will probablly need to get Cometics in order to get the correct bore size/thickness. It'll also optimize your quench area. If it were me, I'd do:
70cc heads, .040" Cometics (4.080" gasket bore), advance the cam 2*. That'll give you 11.7 SCR and 8.5 DCR.
70cc heads, .040" Cometics (4.080" gasket bore), advance the cam 2*. That'll give you 11.7 SCR and 8.5 DCR.
Last edited by jeremym; 03-25-2007 at 01:06 AM.
03-25-2007, 12:37 PM
#9
Originally Posted by jeremym
I have a .060 cometic on there now. Should I use them,and build the head off of that gasket? Thanks for the info on the LS2 gasket. I did not think of that.What if I leave the cam alone then what should the specs be on the head and the gasket?
Originally Posted by jeremym
Why a 4.080 gasket and not a 4.060 gasket? If I dont mess with the cam then what should I do?( cc? gasket? ) What spark plugs should I use? Thanks for the help
Last edited by Beast96Z; 03-25-2007 at 12:45 PM.
03-25-2007, 04:38 PM
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Originally Posted by Beast96Z
.060" is thick for a N/A head gasket. If budget is a factor, then I guess you could try and reuse them, however, your quench area will not be optimal. Have you looked on the cam card or box to see if the cam already has advance ground in? It should be after the LSA. 112 + 0,1,2,3, or 4. The cam itself won't really have any effect on which cc size to get on the heads.
You use a bigger gasket than the bore itself. .020" to .050" over is normal. As for the head cc/gasket, I'd do as i stated above. 70cc's and .040" gaskets. You SCR will stay the same, but the DCR will drop due to not having the advance in the cam. If you must use the .060" gaskets, 66cc's will get you the same 11:7 SCR. As for plugs, I've always used the NGK line. TR55's or 6's should be fine.
You use a bigger gasket than the bore itself. .020" to .050" over is normal. As for the head cc/gasket, I'd do as i stated above. 70cc's and .040" gaskets. You SCR will stay the same, but the DCR will drop due to not having the advance in the cam. If you must use the .060" gaskets, 66cc's will get you the same 11:7 SCR. As for plugs, I've always used the NGK line. TR55's or 6's should be fine.
03-25-2007, 05:42 PM
#12
Yes, piston out of the hole matters. I was using a .007" figure, which is average. You can get Cometics from alot of sponsors, but I always buy mine from Thunder because they have a nice selection and get them here quick. You should find out how far out your pistons are before buying the gaskets just incase yours are farther out for some reason.
03-26-2007, 05:55 PM
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Originally Posted by Beast96Z
Yes, piston out of the hole matters. I was using a .007" figure, which is average. You can get Cometics from alot of sponsors, but I always buy mine from Thunder because they have a nice selection and get them here quick. You should find out how far out your pistons are before buying the gaskets just incase yours are farther out for some reason.
