Head gasket ?
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Well i was looking at Cometic gaskets for the LSX block and they have them in 4.125" and 4.185" and GMPP has them in 4.200" will the exact size gasket of my bore work and should i stay away from Cometics i hear they are hard to seal up?
You generally want a touch of clearance between the size of your bore and your head gasket....on my 454 LS3 i have a 4.185" bore and my gasket it a 4.205"...I went with Cometic and plan on using copper spray to aid in sealing, but they generally seal perfectly if the block and head are properly machined....
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Its a brand new LSX build from LME and new Mast 305 heads but i know Cometic recommends a certain finish! I just dont want to be yanking heads for leakage!
I think the 4.185" gaskets are the next size up though which will be .060 bigger than the bore wonder what affect on the comp that will have?
I think the 4.185" gaskets are the next size up though which will be .060 bigger than the bore wonder what affect on the comp that will have?
Why would you go for off the shelf gaskets that might not be the right size for your application? Call up Cometic, talk to them about your set up and have them make you up a set that fits your application. The difference in price might be $10 a gasket to have custom ones made for you.
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Copper spray and pull the fasteners up in three stages. For example if the final torque is 70 ft./lbs.; I'd start at 40 and go through that sequence twice. Then up to 55; then final of 70.
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I seen some guys do the copper spray with the Cometics i sent them a email asking about custom gaskets if they are to high i may just go with the 4.185" ones just wonder what they will do to the comp. ratio being .060 bigger
It should only be a tenth or two of compression. Use this calculator.
http://www.csgnetwork.com/compcalc.html
http://www.csgnetwork.com/compcalc.html
When I kept everything the same and changed the gasket bore to 4.185 the compression went to 11.367:1 . I don't see where that would make a difference at all on power production.
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Yea thats nothing to talk about but i did chat with Cometic today they said they will make any gasket size i want no extra cost and it takes about 3-5 days!
So should i do 4.155" gaskets that would put them .030 bigger?
So should i do 4.155" gaskets that would put them .030 bigger?
If it's no extra cost, I would go with the 4.155 gasket.
If you want them quick, summit has a 4.150 cometic gasket in stock ready to ship today
If you want them quick, summit has a 4.150 cometic gasket in stock ready to ship today
Last edited by 87silverbullet; Apr 18, 2014 at 06:31 AM.
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I'm not in a rush now i'm thing about using the .040 gaskets to bump the comp. up a bit i waiting on some details from the builder but they should put me around 9.7-1 vs 9.5-1.