Cp Pistons Or Wiseco Pistons ?

[-wj-]

I've got an RB25DET series 1, and need new pistons/rings...

Which should I go for, cp pistons or wiseco pistons ?

[R31Nismoid]

What does the builder think?

[T04GTR]

CP'S are good. they usually mesure up all the same. (no variation in size)

wiesco are also very good but usually reqire individual boring as they vary in size a little. ie 1-3thou diferance in diametre

both need balancing and both use good rings (file back) and wrist pins but both like all american pistons have a faily loose piston to bore clearance. so unless the ring gaps are perfect they will "breath" a little

[Marco-R34GTT]

On that note... Has anyone had experience with JUN?

[STATUS]

CP'S are good. they usually mesure up all the same. (no variation in size)

wiesco are also very good but usually reqire individual boring as they vary in size a little. ie 1-3thou diferance in diametre

both need balancing and both use good rings (file back) and wrist pins but both like all american pistons have a faily loose piston to bore clearance. so unless the ring gaps are perfect they will "breath" a little

i dont like cp rings, i would substitute them.... but like R31NISMOID said listen to your builder as there are some brands i just wont use and some require more work to get satisfactory results...

oh yeah do not use thier recommended piston to bore.... way to big.

[-wj-]

CP'S are good. they usually mesure up all the same. (no variation in size)

wiesco are also very good but usually reqire individual boring as they vary in size a little. ie 1-3thou diferance in diametre

both need balancing and both use good rings (file back) and wrist pins but both like all american pistons have a faily loose piston to bore clearance. so unless the ring gaps are perfect they will "breath" a little

breath a little, as in show leak on a leakdown test ?

Can get both for the same money, so it seems the cp ones are the best choice ?

and R31Nismoid, builder doesn't know which one is better

edit : hmmm,mr uras above seems to not like the cp ones ?

Edited June 13, 2007 by -wj-

[BOOSTA]

I work for someone who happens to do alot work with CP PISTONS and abit of WISECO...

The way i look at it is.... If the V8 Supercars and numerous Top Door Slammers use CP Pistons and we havent seen a failure because of a cp piston or ring (aslong as there installed properly!!!!!!) then i think that speaks for itself.

Wiseco arent even in the same league..... there measurements for standard off the shelf pistons vary way too much and dont even get me started on there custom pistons!!!

The only problem with CP PISTONS is the timeframe for custom pistons..... 6 - 8 weeks (but we havent had any returns of custom pistons yet, they look and perform unreal!)

Cheers BOOSTA (Pete)

[R31Nismoid]

breath a little, as in show leak on a leakdown test ?

Can get both for the same money, so it seems the cp ones are the best choice ?

and R31Nismoid, builder doesn't know which one is better

edit : hmmm,mr uras above seems to not like the cp ones ?

Thats a warning sign mate.

If a builder has to ask which are better suited then they havent built an RB before, and certainly havent used a range of pistons.

Is there anyone else you can use? Its a big expense to stuff up

[-wj-]

Thats a warning sign mate.

If a builder has to ask which are better suited then they havent built an RB before, and certainly havent used a range of pistons.

Is there anyone else you can use? Its a big expense to stuff up

the man has done alot of work for me, always top notch. Just no experience with RB25DET's.

so now we have Boosta and Uras saying 2 very different things

Any more opinions ? I'm leaning towards the cp ones, by te way....

[BOOSTA]

WJ........

CP Pistons speak for themselves...... go have a chat to engine builders who use them in many different applications!

The way i look at it is, the proof is in the evidence of the product and the people who use them, I have seen Cp's in engines from the V8 Supercar Engines to V8 Twin Turbo'd Dune Buggies to 2 x Lamborghini V12 engines.

They all use the CP Pistons and the Ringsets provided by CP to suit the pistons.... Having said that Cp Pistons arent responsible for people who sell pistons with the wrong ring sets in them.

Wiseco are great for lots of different options but if you really are chasing pistons that are above the normal.... CP's are a great choice,

Cheers BOOSTA (pete)

[STATUS]

WJ........

CP Pistons speak for themselves...... go have a chat to engine builders who use them in many different applications!

The way i look at it is, the proof is in the evidence of the product and the people who use them, I have seen Cp's in engines from the V8 Supercar Engines to V8 Twin Turbo'd Dune Buggies to 2 x Lamborghini V12 engines.

They all use the CP Pistons and the Ringsets provided by CP to suit the pistons.... Having said that Cp Pistons arent responsible for people who sell pistons with the wrong ring sets in them.

Wiseco are great for lots of different options but if you really are chasing pistons that are above the normal.... CP's are a great choice,

Cheers BOOSTA (pete)

I tend agree with the wiseco comment, we used a lot of wiseco pistons in race bikes (with no dramas) but i have heard from plenty of skyline guys (not from personal experience mind you) that the wisecos are not the greatest.

comparing V8 supercars and top fuelers to your average rb is hardly a good comparison.

Overall the most important factor with pistons is the machinst and the installer.... both of with determnine the sucess or failure of a build. I can recount 100's of stories of late of customers who have engines built that are so loose they trip the knock sensors..... these were built by so-called reputable shops.... the same guys who build top end v8 engines...

[sinistaGTR]

I use wisecos in my r33 and wrx find them to be a great piston i highly reccomend them.

[Abo Bob]

I haven't heard of any CP's failing for reasons of bad manufacturing but I haven't heard of any Wisecos doing that either. Have you Pete? (Not attacking, just asking.)

I used Wisecos because they have a longer skirt so I think they stay more square in the bore which should long term result in less bore wear. Also the skirts are teflon coated from factory so less friction.

I think they recommend something like 5-6 thou piston to bore clearance (can't remember for sure though tbh). I used 2.5 and have had no issues.

[STATUS]

I haven't heard of any CP's failing for reasons of bad manufacturing but I haven't heard of any Wisecos doing that either. Have you Pete?

I think they recommend something like 5-6 thou piston to bore clearance (can't remember for sure though tbh). I used 2.5 and have had no issues.

yeah same deal with ARIAS, i use alot of ARIAS (great cheap piston) in jap engines and unless you tighten them up they rattle like all hell and you get excessive ventilation.

[BOOSTA]

URAS... and ABO,

Your both correct, the wiseco's are a decent piston and readily available in many different shops.... In the end if the engine builder doesnt know how to install pistons correctly (hell CP even have instructions to follow for there pistons and rings)

As for the difference between the V8 supercar pistons etc, they are all made by the same machinists at CP Pistons and with the same material as ur standard off the shelf Forged Rb20, Rb25, Rb26, Rb30, Rb30/25/26head, etc etc <--- CP Stock

The only difference in the standard forged pistons to the customs is things like X Forgings, lateral gas ports, vertical gas ports, anti detonation grooves etc etc ( plus the basic things like to suit certain applications etc and heads, pin heights, flat top, dome, or dish, blah blah.... skirt length can be changed in custom aswell.

I have seen and spoke to many different workshops within Australia and we are still waiting to see a Real CP PISTON Failure...... or even a Ringset Failure that hasnt been caused by incorrect tunning (detonation)

Some of the shit I have heard scares even me sometimes with regards to what people do to engines,

Cheers BOOSTA (pete)