This guy is parting out a whole DS it looks like, and is not able to answer alot of the questions that he has been getting. Surely someone can tell from the stampings, or just plain good old experience, what the compression might be on this piston. I know it's not stock, and looks alot like Casey's 11.5/1 but I have no experience with the others floating around out there. I'm asuming it is one of the RWR pistons since the cams he sold were from there.
Anybody?
Compression ratio?

 

I had one of those CP stock bore pistons before going with the 730 kit, mine was 11.5:1, sure looks familiar.

 

Ace,
Its a piston and cylinder!! What do I win?
Scott

 

I meant can anyone tell from the inside shots of the piston, where it says CP and some numbers, what compression that that particular piston is... SHEESH, you Northern Californians! But for your effort I guess you have won some Apple Pie time around the campfire with some tall tales. By the way, are going to make it to Dumont for the races Dec. 8th???

 

I personally think it looks 11:5-1 also. It doesn't look like Seth's 12:1 and not like stock so that is my guess.[img]i/expressions/face-icon-small-smile.gif[/img]

 

I will look at gettin down for the races. I just may have to work in Bakersfield that week.

Somewhere I have a shot of the bottom of a CP 11.5 to one. But I bet if you call Elliot at Ron Wood Racing he will tell you.

Scott

 

I am 99.9% sure that is 11.5:1

 

<div class="FTQUOTE"><begin quote>Originally posted by: DSNUT

I am 99.9% sure that is 11.5:1</end quote></div>

Agreed!!! I have no doubt that piston is an RWR 11.5-1

 

Thanks, that is what I was hoping for. Can't afford the race gas route. I needed a cylinder though, so for the price the piston ended up being a bonus.
How's it going to work in conjunction with those RWR A1/A2 cams that are coming with it???

 

When in doubt put a layer of clay over the piston and temp fasten the head on and turn the motor over by hand with the cams in. Look at the thickness of clay left after the valves make indentions (is that a word? lol)

I doubt it will be an issue but it is a crude way to verify clearance. Remember that you need a few extra thousandths for rod and valve stretch at high rpm and you are good to go.