piston depth ques.

[TONYT]

what is the effect on compression when a piston is set up at a negative point versus a positve one ,,,ie -0.010 vs +0.010

as in at -0.010 the compression is 10.1.1, what would the same combo be at
+0.010

thanx for any and all responses in advance

[bbfstanger]

i wouldnt run the piston that far outta the hole.
.007 is pushing it.
it does tighten the quench,but you run the risk of piston contacting te head,like when it rocks at tdc.

[NXcoupe]

wallaceracing.com is your friend. Jon, if he's running a .070 gasket, that's not going to be an issue then.

[bbfstanger]

yeah im assuming std .041

[NXcoupe]

or .036, that's what my 8548's were compressed.

[TONYT]

i have and plan on using a set of cometic 0.065 comp.,and i got them 0.080 so as not to rub the piston as it exits the hole during operation,could have maybe went 0.060 but all they had was the.80

[2Fast4You]

I believe optimum deck clearance would be .005, this would give you valve to piston clearance as long as everything else is matched for it. I would say you do not want to have the piston itself come above the deck other than the dome if it's a dome piston.

[Rick93coupe]

On an old Windsor I had, my block was decked incorrectly and the piston was at zero deck on one side and .010 out of the hole on the other side. I had the the block squared up at another shop, so they were both .010 out of the hole and just used a thicker gasket. I don't remember which one. That being said, with that thick of a gasket you bought, it should drop your compression. Are they out .010 now?

[TONYT]

yea i was told they were out that far,and when at tdc you can drag a finger nail and bump the top of the piston,,was mentioned to me to make sure they all were that way,and on monday i will,but the thickness of this gasket susposedly place the comp. back to the 9.5.1 i wanted

[TONYT]

oh yea there is susposedly no piston to valve clearance issues now even with it out that far,they were clayed on wed. last week.