Deck height, compression ratio, and valve relief flat top pistons, In a 2.0 |
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Deck height, compression ratio, and valve relief flat top pistons, In a 2.0 |
emerygt350 |
Jul 13 2023, 11:41 AM
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#1
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Advanced Member Group: Members Posts: 2,144 Joined: 20-July 21 From: Upstate, NY Member No.: 25,740 Region Association: North East States |
Ok, my question of the day:
Put my new 96mm pistons and cylinders on and measured deck height, .033 all the way around. Let's say .032 to be conservative. I will not be running head gaskets. The calculator gives me 8.8 CR at .033 8.6 CR at .043 8.4 CR at .053 The pistons have a valve relief (pretty large) cut. I am shooting for 8.4 CR. Heads are in the shop so I can't check the CC yet. Everything I read says .04 - .06 for deck height. With the valve relief do I need to worry about going lower? If I had dishes would you measure from the edge of the piston or the dish? |
Montreal914 |
Jul 13 2023, 12:13 PM
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#2
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Senior Member Group: Members Posts: 1,587 Joined: 8-August 10 From: Claremont, CA Member No.: 12,023 Region Association: Southern California |
Not sure I understand how you can establish the CR with the gaps you are showing if you don’t have the head volume (IMG:style_emoticons/default/confused24.gif) . Also make sure you consider the valve pocket in the pistons as volume.
The 0.040” gap is not necessarily for interference between piston top and valve but piston top and head face. Hopefully my comments can help answer your question… |
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