Piston Gas Porting

arai59 wrote:

All good and fine John. But what color will your bike be ?

Now thats funny, I don't care who, yo Momma is!

keith1 wrote:

thompsonmx100 wrote:

interesting I've never heard of that before. It makes sense but does sound like something you would want to use in a race bike rather than a street bike

and this all means what to the 99.8% of us who run on the street...?:laugh:

It means nothing to a street rider. It's for race stuff. It's just one more thing, they have done to Z's for years.

I think it is important to archive as much info as possible.

Some people will someday hand their bikes down, to their children. Where are they going, to get info? How will they learn?

All the old dudes are getting older. It takes me alot of time, to find some info, how hard will it be in 20 years?

There has been many things done to these bikes, we havn't even, talked about yet.

I hope that many people archive, as much as, they can.

kzz1p wrote:

keith1 wrote:

thompsonmx100 wrote:

interesting I've never heard of that before. It makes sense but does sound like something you would want to use in a race bike rather than a street bike

and this all means what to the 99.8% of us who run on the street...?:laugh:

It means nothing to a street rider. It's for race stuff. It's just one more thing, they have done to Z's for years.

I dunno.....I'ma gonna havs to ask Plummen on dis. Heza oughta know.

What is the lowest compression ratio, you have seen them used with? The lowest I have seen is 10:1 ratio.

I used them on the engines I built, they are flatheads, at about 9.5:1 compression. Not sure how much of a difference just the gasporting made. I changed to a piston that was much lighter, with a lower tension ring pack, and gasported it, and netted about 10% peak horsepower gain on the dyno.

kzz1p wrote:

keith1 wrote:

thompsonmx100 wrote:

interesting I've never heard of that before. It makes sense but does sound like something you would want to use in a race bike rather than a street bike

and this all means what to the 99.8% of us who run on the street...?:laugh:

It means nothing to a street rider. It's for race stuff. It's just one more thing, they have done to Z's for years.

I think it is important to archive as much info as possible.

Some people will someday hand their bikes down, to their children. Where are they going, to get info? How will they learn?

All the old dudes are getting older. It takes me alot of time, to find some info, how hard will it be in 20 years?

There has been many things done to these bikes, we havn't even, talked about yet.

I hope that many people archive, as much as, they can!

ArthurGoVroom wrote:

What is the lowest compression ratio, you have seen them used with? The lowest I have seen is 10:1 ratio.

I used them on the engines I built, they are flatheads, at about 9.5:1 compression. Not sure how much of a difference just the gasporting made. I changed to a piston that was much lighter, with a lower tension ring pack, and gasported it, and netted about 10% peak horsepower gain on the dyno.

Was your 10% gain, in the upper RPM range?

arai59 wrote:

kzz1p wrote:

keith1 wrote:

thompsonmx100 wrote:

interesting I've never heard of that before. It makes sense but does sound like something you would want to use in a race bike rather than a street bike

and this all means what to the 99.8% of us who run on the street...?:laugh:

It means nothing to a street rider. It's for race stuff. It's just one more thing, they have done to Z's for years.

I dunno.....I'ma gonna havs to ask Plummen on dis. Heza oughta know.

just sent a set of 1197 pistons to larry c that were gas ported,around 13:1 depending on what head you run em with.

i seem to remember that being done to dirtbike pistons also many years ago,maybe mid-late 70s

PLUMMEN wrote:

i seem to remember that being done to dirtbike pistons also many years ago,maybe mid-late 70s

I can remember when Vance & Hines sold them that way, right off the shelf. It was their high compression units. Most piston companies charge extra. Most used a .040"-.060" dia. holes for the ports.

They have been used in all kinds of stuff, over the years.

Plummen, do you remember how many holes, those pistons had in them?

We usually do 8

APE Jay wrote:

We usually do 8

Jay

Does the wear rate of the rings increase?

kzz1p wrote:

Seems like the holes would tend to get plugged with carbon after running for a little while longer than 1/4 mile

Good Luck!