Thinner Gaskets VS. Milling Heads
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Thinner Gaskets VS. Milling Heads Trying to bump up compression in my LS1 with a 234/242 110+4. What are the pro's and con's of each? How much is it to mill heads?
Thanks
Thanks
cons would be having to flycut the pistons. Pro's would be a good power gain across the board. I had milled heads to begin with. I just went with a bigger cam and thinner gasgets and should be damn near the 500 mark once it's re-tuned
I have been looking at this, to me the question is thinner gasket or not. Seems like a lot of guys have problems with Cometics leaking, so I plan to bump compression but stick with the stock GM MLS gaskets.
thinner gaskets will provide more scr and dcr,
stock oem ls gaskets are in the .050-.055 compressed thickness
range, with a .005-.010 out the bore pistons for stock bottom ends.
thinner gaskets will cost more than having heads milled, but ptv will need to be checked,
thinner head gaskets also affect quench and usual rate at machine shops to mill alum. heads is about 50$ pair for .010-.015
stock oem ls gaskets are in the .050-.055 compressed thickness
range, with a .005-.010 out the bore pistons for stock bottom ends.
thinner gaskets will cost more than having heads milled, but ptv will need to be checked,
thinner head gaskets also affect quench and usual rate at machine shops to mill alum. heads is about 50$ pair for .010-.015
Ideally, do both.
Thinner gaskets reduce the quench, milling does not. Lowering quench is desirable for knock/detonation resistance. Ideal quench should be in the .030-.040" range. Gasket thickness minus the piston out of the hole dimension = quench.
That cam on a 110 lsa will likely require flycutting with stock heads/gasket anyways, so as long as you're making room, why not optimize compression and quench?
Cometics seal just fine if you take some time to insure the head and block deck surfaces are clean and smooth. There are also several other thinner-than-stock head gasket choices out there that aren't MLS....SCE (copper), Mr Gasket (graphite), etc.
Thinner gaskets reduce the quench, milling does not. Lowering quench is desirable for knock/detonation resistance. Ideal quench should be in the .030-.040" range. Gasket thickness minus the piston out of the hole dimension = quench.
That cam on a 110 lsa will likely require flycutting with stock heads/gasket anyways, so as long as you're making room, why not optimize compression and quench?
Cometics seal just fine if you take some time to insure the head and block deck surfaces are clean and smooth. There are also several other thinner-than-stock head gasket choices out there that aren't MLS....SCE (copper), Mr Gasket (graphite), etc.
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From: Troy,MI.
Originally Posted by vettenuts
I have been looking at this, to me the question is thinner gasket or not. Seems like a lot of guys have problems with Cometics leaking, so I plan to bump compression but stick with the stock GM MLS gaskets.
Thats what I did. Milled the heads .020" and used the stock GM MLS gaskets. Worked out great.Car runs great on 93 octane fuel. No pinging,great low end torque and instant throttle response.
Originally Posted by 02SOMWS6
dont forget your get a ARP head stud kit also. There should be no issues with cometic's with a head stud kit
Why would he need a head stud kit??? As long as you ensure that all surfaces are flat and smooth you will have no problems. I run .040 cometics with a similar cam grind and I use all GM bolts and have never had any problems. Correct preparation is key.
FelPro Head Gaskets I've used FelPro's and have had no leaks. The 1041's are .041 and will raise the compression a little. I just went to them in an effort to get a little lost power.
Bob K.
Bob K.
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From: BFE
Originally Posted by 02TransAm/Batmobile
Trying to bump up compression in my LS1 with a 234/242 110+4. What are the pro's and con's of each? How much is it to mill heads?
Thanks
Thanks
To answer your question, it depends how much you want to bump compression. But it is always better to reduce gasket thickness first depending on you piston deck height value.
It would be easier to answer this question if you gave your motor specs.
Originally Posted by RGKSR
I've used FelPro's and have had no leaks. The 1041's are .041 and will raise the compression a little. I just went to them in an effort to get a little lost power.
Bob K.
Bob K.
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From: Southside Chicago
Stock LS1 with Stock LS6 Heads Predator. Trying to get DCR into the mid 11's and SCR into the mid 8's.
Will do valve reliefs if necessary. Trying to figure out how big of a valve relief also.
Will do valve reliefs if necessary. Trying to figure out how big of a valve relief also.
Originally Posted by KONG
Why would he need a head stud kit??? As long as you ensure that all surfaces are flat and smooth you will have no problems. I run .040 cometics with a similar cam grind and I use all GM bolts and have never had any problems. Correct preparation is key.
Originally Posted by KONG
I run .040 cometics with a similar cam grind and I use all GM bolts and have never had any problems. Correct preparation is key.
Originally Posted by 02SOMWS6
true, but a head stud kit will have more clamping down force. I always seem to go for over kill. I also lifted a head on spray with stock gm bolts so I think if it's apart it should get a head stud kit to keep it together longer
point taken
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From: Midland, GA
Originally Posted by 02TransAm/Batmobile
Stock LS1 with Stock LS6 Heads Predator. Trying to get DCR into the mid 11's and SCR into the mid 8's.
Will do valve reliefs if necessary. Trying to figure out how big of a valve relief also.
Will do valve reliefs if necessary. Trying to figure out how big of a valve relief also.
