Gas port diameter

[RCJ]

What size drill do you use for vertical gas ports.
What are the specs for an accumulator groove between the first and second ring?

[dannobee]

0.040" or #60 drill size. Don't forget about a slight chamfer at the top of the hole. And some sort of soft sacrificial shim in place of the ring will help eliminate the burr when the drill bit breaks thru.

[Protech Racing]

I use 050 or 58. Broke a couple of the 040 bits off in nice pistons.

[MadBill]

What's the downside to larger holes, say 1/16"? The bits would be less prone to breakage and the holes to carboning up...
(The Goodson kit comes with 1/16" bits.)

[dannobee]

Probably nothing. They'll be less likely to plug up with carbon. Theoretically would push the ring out harder against the bore on the power stroke. And would be less likely to break the drill bit.

[Kevin Johnson]

https://rehermorrison.com/tech-talk-22- ... gas-ports/

[RCJ]

Does Goodson make a lateral port kit for .039 rings.

[dannobee]

They do make one for 0.043" rings. You could probably just lop 0.004" off the other side with an end mill.