booost....... and boost

[urwurznitmahre]

what is the accepted psi that it becomes a good idea to gas port the ring lands to keep the rings seated, against the cyl walls..

and does bore size change the psi limit on when to start to drill the pistons for gas ports to ring lands

[squirrel]

Re: booost....... and boost

I never could figure out why people do the gas porting thing. There's some clearance between the ring and the land above it, doesn't this let in all the pressure necessary to seat the rings?

[urwurznitmahre]

Re: booost....... and boost

I never could figure out why people do the gas porting thing. There's some clearance between the ring and the land above it, doesn't this let in all the pressure necessary to seat the rings?

I think the pressure differanchal(sp?) between compression ring #1 and #2 causes ring flutter and unseats the rings.. and why gas porting is done..
I was just thinking that as some point (psi) of boost the tension of the rinds on the walls wouldn't be enough alone..
we've done it before, on n/a engines.. didn't know if there was a rule of thumb on blown ones (s/c or turbo)

[squirrel]

Re: booost....... and boost

the pressure from above the ring gets behind it whether or not you drill the holes, that's how compression rings work. there is far more force on them than just their tension. Think about why cylinder bores wear the way they do.

[urwurznitmahre]

Re: booost....... and boost

the pressure from above the ring gets behind it whether or not you drill the holes, that's how compression rings work. there is far more force on them than just their tension. Think about why cylinder bores wear the way they do.

I totally understand that,,
and I don't know why gas porting is "needed" in some circles..
and the reasons behind it..
the guys I've worked with are older and lots of wins, so I tend not to question why they do stuff..
but the engineering student in me needS TO KNOW THE WHY,HOW, extra

[squirrel]

Re: booost....... and boost

If you ever find out please let me know...

[revolutionary]

Re: booost....... and boost

Gas porting usually helps with thin (1/16 or less) rings that are backcut or don't have much tension seal quickly and fully. D-wall 1/16 top rings (normal size) or larger are really too stiff to benefit from gas porting because the tension of the ring itself will seal it up and you won't see any benefit from gas porting. According to Dave from CP, it really doesn't matter whether it is lateral or vertical gas ports because they act the same. Vertical ports COULD clog up quicker IF the engine isn't right - mixture, oiling, etc. For the most part, if you are running gas ports, the rings you are using won't last long enough to have clogged gas ports so that is irrelevant.

[revolutionary]

Re: booost....... and boost

I never could figure out why people do the gas porting thing. There's some clearance between the ring and the land above it, doesn't this let in all the pressure necessary to seat the rings?

Current technology has gotten to where we can run as tight as .0003" ring to land gap and that doesn't allow enough gas to get in there quick enough. Old stuff ran .001-.003"

[BetterWithBoost]

Re: booost....... and boost

We're using gas port pistons because of the boost level we're at.
I don't know the entire science behind it, but if you're staying
below 10 psi with a solid bottom end of less than 10:1 CR, you
should be fine.