drilling holes in piston

drilling holes in piston - 06/06/12 09:42 PM

when drilling holes in the top of the pistons at the top ring.(compression pushes the ring out for better sealing) What size drill bit, and do you drill down to the second ring also

Posted By: BradH

Re: drilling holes in piston - 06/06/12 09:58 PM

is to do a Google search on "gas porting pistons" and spend some time looking at the articles & tool links that come up.

Posted By: 340SHORTY

Re: drilling holes in piston - 06/06/12 11:34 PM

Is that procedure even done anymore? I remember it from years ago but nothing in the last few years..

Posted By: StukaJU87

Re: drilling holes in piston - 06/06/12 11:41 PM

I bought my 440 from a member here and the pic of the block with the heads off shows a hole in the center of each piston.

Posted By: StukaJU87

Re: drilling holes in piston - 06/06/12 11:45 PM

Attached picture 7239292-4402pistons.JPG

Posted By: slantzilla

Re: drilling holes in piston - 06/07/12 12:14 AM

Quote:

I bought my 440 from a member here and the pic of the block with the heads off shows a hole in the center of each piston.

That is a machining dimple from centering the piston. I would hope it does not go all the way through.

To the OP, if you don't know what you're doing, gas porting is a very quick way to ruin a good set of pistons. Google will be your friend for sure.

Posted By: JohnRR

Re: drilling holes in piston - 06/07/12 03:30 AM

Quote:

Quote:

I bought my 440 from a member here and the pic of the block with the heads off shows a hole in the center of each piston.

That is a machining dimple from centering the piston. I would hope it does not go all the way through.

To the OP, if you don't know what you're doing, gas porting is a very quick way to ruin a good set of pistons. Google will be your friend for sure.

what he said

Posted By: Cab_Burge

Re: drilling holes in piston - 06/07/12 04:27 AM

All gas porting, vertical or horizontal, should be done by a competent Hi Po shop or a piston company with the proper equiptment, not a piston vice and drill motor

Posted By: ehbody

Re: drilling holes in piston - 06/07/12 07:38 PM

Stupid question.
But what does "gas porting pistons" do?

Posted By: 71birdJ68

Re: drilling holes in piston - 06/07/12 07:54 PM

I gas ported a set of motorcycle pistons years ago, but they tell me that the way rings are made today it's not needed. Talk to a motor expert.

Posted By: JohnRR

Re: drilling holes in piston - 06/07/12 07:57 PM

Quote:

Stupid question.
But what does "gas porting pistons" do?

It puts compression pressure behind the ring forcing it against the piston and the bore for a better ring seal. I have a set of JE pistons that had it done. Only negative thing is once the holes get filled with carbon it's the same as a piston with no holes drilled.