What size pistons to get?

TurboOCD

Kitty Eating Buddhist
Apr 8, 2006
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DE
What size pistons do you guys think I should get? I've been talking to a shop and they said they don't like to bore the engine out much at all. I'm planning on around 500whp so would .20 over be ok?
 

GrimJack

Administrator
Dec 31, 1969
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Always buy the smallest you can. The extra size will not make a significant difference in your displacement, and going 20 over means you can bore it out again if you need to.

That said, the shop should be the one to tell you what size is required. They need to measure the bores and make sure it's not worn more than 20 already.
 

TurboOCD

Kitty Eating Buddhist
Apr 8, 2006
70
0
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DE
GrimJack said:
Always buy the smallest you can. The extra size will not make a significant difference in your displacement, and going 20 over means you can bore it out again if you need to.

That said, the shop should be the one to tell you what size is required. They need to measure the bores and make sure it's not worn more than 20 already.

So basically just wait for the machine shop to tell me what pistons to buy. That's cool. As you can tell this is the first time I'm having any of this stuff done. I guess I should wait to find out what size headgasket to get too then?
 

Yellow 13

Lurker
Apr 4, 2006
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If you want to lower the compression a little you can get a thicker headgasket. 935motorsports makes a 3mm. You may want to wait and see what the machine shop says about your head before you make any choices though.
 

aljordan

LEADED FUEL ONLY
Jul 14, 2005
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I would run a stock sized head gasket. No sense in putting in a 3mm head gasket when you are already running 8.5-1 compression. Those thick head gasket like that are used in motors with high compression to help lower it in preparation of running forced induction.
 

gixxer750

2jzget comingsoon!
Mar 30, 2005
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you need to find out what size pistons you are going with and how much material will be taken off of the head and block suface. You then need to order a head gasket accordingly to maintain around the stock compression ratio.
 

Yellow 13

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BIG-AS~2-EDIT.jpg



This Size!:icon_razz
 
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Clip

The Magnificent Seven
Oct 16, 2005
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its not the size of the ship, its the motion of the ocean...besides, that roll of film looks like itd be a frikking awesome sized piston in, say, a blender...