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Piston above deck question

Old 03-03-2019, 04:57 PM
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i just measured mine to confirm. it was actually really easy. i would recommend double checking you are at top dead center buy using the piston stop/average out method. then even out the piston rock on both sides. my block was skimmed a decent amount because its a reserve and my N/A pistons are all out .008-.010. i would get .020 on one side and .001 on the other give or take. after i even it out so the piston is no longer in a "rocked" state they all matched my build sheet.
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Old 03-03-2019, 10:53 PM
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Originally Posted by Swayc09 View Post
1 did notice they have a 1.335 CH and that is bigger than other i have seen from wiseco. typically finding 1.311. also my piston is 4.060, can i run a 4.060 bore diameter gasket or 4.100?

GM Gen III/IV Small Block V8 LS Series .070" MLS Cylinder Head Gasket, 4.100" Gasket Bore.
GM Gen III/IV Small Block V8 LS Series .070" MLS Cylinder Head Gasket, 4.060" Gasket Bore.
1.335" is for a 6.098" rod with 1/16" x 1/16" x 3.0mm rings (these need more CH to accommodate the .031" extra width of the ring pack)
1.311" is for a 6.098" rod with 1.2mm x 1.2mm x 3.0mm rings

Use a 4.100" gasket. You don't want ANY hint of gasket overhang into the bore. Plus, the top of the bore should be chamfered and will be larger than the 4.060" bore anyhow.
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Old 03-04-2019, 10:56 AM
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I will double check and measure again. If I measure in the middle of the piston I assume it would be not accurate as I have dome pistons. Iíll check both top and bottom to see what it comes out on the bottom.

I will Iíll get the 4.100 gaskets.
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Old 03-05-2019, 09:55 AM
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Originally Posted by Swayc09 View Post
Local machine shop that did the work, did another 6.0 With same piston and sticking out of block. They did deck my block because I had to sleeve one cylinder. But I doubt they took off that much. I want to say it was 10 thousandths. So .070 gasket and send it lol
That actually adds up. Adding up the 1.335" compression height, 6.098" rod length, and 1.811" half stroke is 9.244". The iron blocks usually have a deck height of 9.230" so without cutting the deck at all, you're already out .014". Take .010" more off and your at .024".
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Old 03-05-2019, 01:12 PM
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well that makes perfect sense. so it looks like i run a .070 gasket and i wil be good
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Old 03-06-2019, 02:16 PM
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Wow, I just had a set of Wiseco’s .017” out and thought was very excessive and used a .051 gasket. Feeling better about it now that I’ve seen this. Why Wiseco uses 1.335 I can’t figure while most other piston mfg 1.330 or less
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