Awhile back I bought a set of shelf CP pistons 84mm bore, 9:1 compression in anticipation of using them on my new engine. Well over the course of my build things have been upgraded and upgraded and now I have a lofty power goal of 750whp on race gas and 500ish on pump.

I called CP today to see just what the rating on their shelf pistons were and they told me the shelf pistons were good to 600hp but the shelf pins were only good to about 500hp. This has really discouraged me. My car will spend most of it's life below 500whp as a cruiser and weekend car, but it will be setup to run a few races (BOTI and local events) and I'd like to have the option of turning it up.

So what do you guys run for pistons? Do all you high hp guys just run shelf pistons and chance it? What pistons options should I look for if I decide to go the custom route that CP recommended. I see in some people's posts that they have upgraded wrist pins that CP offers. Is that all I will need to be able to handle the power? If I order the upgraded wrist pins, do I have to send my pistons back to get them fitted, or are they just a "one size fits all"?

I understand that some of this may be "secrets of the trade" and I may not get too many answers, but I figure it's worth a shot. I don't want to risk a piston letting go and destroying my beautiful head and block.

 

we ran off the shelf CP Pistons with standard wrist pins for 2-3 seasons at over 700 whp without any issues at all.

our current engine has the upgraded CP Wrist pins in it since we figured why not when putting it together..

..but i would feel comfortable running standard wrist pins in my engine still knowing how well they have treated us in the past

you do not have to send your pistons back to get upgraded wrist pins, you can just purchase the pins and they will fit just fine -- they are a thicker sidewall wrist pin but the outer diameter is the same

 

Off the shelf CP pistons and upgraded pins here making well over 800+ Whp.

 

awesome thanks guys

 

we use off the shelf ****, and have put up 179mph.

 

Do I have to get the pins straight from CP or does anyone that sells CP pistons have them?

 

anyone that sells CP can sell you the upgrade pins

(sent you a pm)

 

CP's here 800+ hp! With both upgraded and non upgraded wrist pins...

 

I have seen 900 plus on shelf CPs with the 9310 pins. You will be fine.

 

Aaron, you really shouldn't mix and match things like that.

 

I am running shelf cp pistons with the upgraded wrist pins at around 850whp

 

we have one car on a shelf cp and shelf wrist pins making 890whp

 

shelf cp's with upgraded pins. over 700 somewhere. he hee.

 

Anyone using shelf wiseco's, with or without upgraded pins, in the 750+ range?

 

LOL that same thing ran through my head when i read his post.

 

I upgraded mine 114 from cp direct here is the dif.



dont run yet

 

Ha ha it was with two different motors!!! Sorry for not being clear! LOL

 

i had problems w/my shelf wisecos and there heavy pins.had a tapping noise in the motor and when i took it apart i could wobble the piston side to side on the pin almost covering the wrist pin center hole.

 

Dang....this worries me!! I sent out my block to ERL for the "royal treatment" and Sean convinced me to go with Wisecos...they are supposed to be custom to their spec and they have used them in many of their builds. They even added ceramic coat on top sides and belly of the piston for less than the CP's which is what i have always ran...

AHhhh im worried now...we didnt check the bottom end i have heard nothing but good from ERL, so i let them assemble the motor also. I was impressed with the spec sheet that came with it. Someone please make me feel better....!!! We are also going for 800whp

 

i use custom wiseco's in my motors. they are pretty much bomb proof IMO.

typically use a JE if its an off the shelf piston, high hp car

low power stuff we use shelf stock wiseco's most of the time, every now and then a cp

 

BOMB PROOF! Makes me feel much better!

thanks!

 

ya i would use a custom wiseco but not the shelf ones for high hp.

 

780 with shelf wisecos over 100 pulls and 150 passes just dont panic about the noise

 

I can't remember but didn't tony have a problem with a set of pistons that broke @ the wrist pin location? It was about 1-2 years ago???
-Chuong

 

Yes I believe they were shelf wiseco's and then he put JE's in the car. That very post is my reasoning for asking this question.