Cp Stocking Pistons Has Major flaw!!

[MarsaGSX]

Mahle user here..
runing them for two years.. 8.5:1cr I got 0.005" wall clearance..I know bit high for low extension pistons but pushed 40PSI of boost on 35R w 1.06ar openT3 on pump gas and Traped 135MPH with launch like old granny. I can recommend them..plus found Mahle now doing 9:1cr what a shame..

BTW heard many times about wisecos cracking piston skirts.DSM..Nissans.. just try google...
Google

okay.. I saw on buddies RB26 cracked JE piston skirts on all 6 pistons..we found those england assholes we bought from bored wrongly engine..
Good luck with your rebuild
Venca

 

[RipperXX]

90tsiawdturbo please don't get me wrong, I just don't like posts that start off with "I heard". You were the first person I have ever read about making such a claim. I looked into it a little more on my own time, and it seems it does happen from time to time. Could be user error though for all I see at the moment.

I wasn't trying to "yell" at you. I just don't like un-sited information like that thats less common. You get people on many other forms spreading a lot of mis-information using that "I heard" crap.

 

[1997_GSX]

Arias 10:1s here, good luck so far!

 

[keltalon]

So what pistons do u guys recommend?

Well I will say I have been using ross pistons for years and not problem. Like was stated in another post of mine the only reason I tried the cp is because those fools talked a good game and gave me a good price to put them is a build. I have always had my concerns about the bid valve pocket I spoke to cp about the issue with the intent to help them with the design those arrogant jokers wanted to blame someone else. Here is the email that was sent back to me by the sports compact manager and I quote


"I appreciate the feedback. We had some 4G63 customers that were always requesting deep valve reliefs. On a custom order, it is no problem at all. Let me know how deep you want it, we will do it. I may also have info here on the depth on Ross pistons if that’s what he wants.



We often get blamed by companies that did not tell us to change anything. Their out is to blame CP made it wrong. You know if we didn’t make it as you requested, we will remake the part. We do not remachine the parts, so that is not true in that post. We get custom orders all the time where the guy wants these super deep valve reliefs, we make them as requested. As far as the 4G63 pistons, we have more than 1000s that do not have a problem. If every engine had a problem, this wouldn’t be the only email I got on this issue this year.



Not to mention the link is a BMW piston not a 4G63, not sure how you can relate the two different engines. You detonate, you will have problems.



Best Regards,



Darius Tarman



Sports Compact Manager






1902 McGaw Irvine, CA 92614 USA

P: 949-567-9000 949.498.1800

F: 949-567-9010 949.498.2355

www.cppistons.com | Web hosting services by EarthLink Web Hosting Home



A member of Pankl Racing Systems



Facebook: CP Pistons-Carrillo"



The only problem I have with the point the finger game is that the pistons I bought was a stock unit not custom so the design is flawed and needs to be changed enough said!

 

[floader]

One of the main reasons there are so many piston manufacturers is they like to specialize on a few engines. They can all make pistons for anything, but usually put most of the R&D into a few applications. CP makes great pistons for the V8 domestic guys. Ross has a really nice piston for the 4G. Diamond does a really nice job on blower LSX stuff. Probe does alot with small block Fords. You have to be willing to work with the manufacturer if you are going to try and use there stuff in something they dont do all the time.

 

[keltalon]

One of the main reasons there are so many piston manufacturers is they like to specialize on a few engines. They can all make pistons for anything, but usually put most of the R&D into a few applications. CP makes great pistons for the V8 domestic guys. Ross has a really nice piston for the 4G. Diamond does a really nice job on blower LSX stuff. Probe does alot with small block Fords. You have to be willing to work with the manufacturer if you are going to try and use there stuff in something they dont do all the time.

I agree 100% that is why i wanted cp to match the ross unit because I love the low tension oil ring and the ring seal of the cp piston rings over the ross ones.

 

[JacksonAuto]

There are other manufacturers that use the low tension oil ring that would avoid a lot of running around on your end. The CP's make some nice stuff for NA motors but when it comes to boosted engines their designs left a lot on the table. Unless they changed their designs....

 

[keltalon]

There are other manufacturers that use the low tension oil ring that would avoid a lot of running around on your end. The CP's make some nice stuff for NA motors but when it comes to boosted engines their designs left a lot on the table. Unless they changed their designs....

If you don't mind let me get that list of other manufactorers. Thanks.

 

[JacksonAuto]

Wisecos for one and we use them on our Venolias, too.

 

[keltalon]

Wisecos for one and we use them on our Venolias, too.

Thanks for the heads up! PM me a good price on a set of venolias 60over

 

[nitrouskris]

what is the part number you had on the cp piston ???

 

[keltalon]

what is the part number you had on the cp piston ???

part number SC7202

 

[nitrouskris]

part number SC7202

ok I had some problems with that design also...well if anyone in the future is looking to buy cp pistons call atomic speedware and ask for there custom 4g63 cp pistons designed by Nick Arias 3rd

 

[keltalon]

ok I had some problems with that design also...well if anyone in the future is looking to buy cp pistons call atomic speedware and ask for there custom 4g63 cp pistons designed by Nick Arias 3rd

I have been running a cp custom 8:5to1 60 over slug for a while with no issues. I sent them one of my old ross units and they matched it. The only reason I did this is because of how well the cp rings seal

 

[boosting_laser]

So my #1 rod bearing decided to also slim down for the new year. Anywho, I checked my slugs they definitely show heat spots & where in the verge of burning through. Kinda hard to get a good pic, but the sharp edge is a little warped.

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[keltalon]

So my #1 rod bearing decided to also slim down for the new year. Anywho, I checked my slugs they definitely show heat spots & where in the verge of burning through. Kinda hard to get a good pic, but the sharp edge is a little warped.

You must be logged in to view this image or video.

That sharp edge can and will definitely create a hot spot. That is why some guys find it hard to tune out knock with the cp stocking pistons. My custom CP slugs have been holding up well since I started this thread

 

[ThunderChild]

so heres a quick question: would this also apply to CP's 4g64/4g63head piston?

im building a 2.4 and was planning on using eagle rods with cp pistons. reason i was leaning towards cp, is my instructor from school has been using them for about 25 years, and he races a nitrous bug that runs 9.3's in the 1/4 mile. had alot of good things to say about them, but after seeing this thread, im questioning them. i just dont know if the added bore would counteract the valve relief issue.

seems like every piston im coming across is having some major flaw that makes me double check my choice.

 

[wvturbo2]

I've been running wiseco standard pistons for 3 seasons 2 500hp seasons and 1 700 hp season. Around 5-6 miles on the car with no problems.

 

[bryanwheat]

so heres a quick question: would this also apply to CP's 4g64/4g63head piston?

im building a 2.4 and was planning on using eagle rods with cp pistons. reason i was leaning towards cp, is my instructor from school has been using them for about 25 years, and he races a nitrous bug that runs 9.3's in the 1/4 mile. had alot of good things to say about them, but after seeing this thread, im questioning them. i just dont know if the added bore would counteract the valve relief issue.

seems like every piston im coming across is having some major flaw that makes me double check my choice.

Look into arais, mahle, supertech, je, and ross. I wouldn't chance it with these.

 

[keltalon]

Look into arais, mahle, supertech, je, and ross. I wouldn't chance it with these.

CP makes a very good piston. These stocking I found out after working with cp on the a custom set , are spec out by the vendor and is sold to the vendor with their request in compression ratio, valve quench, and diameter and these are set by vendor as a standard piston. But the vendors didn't do thier homework and now we have to deal with the flaw. Now if you contact cp they will build you a custom set that fit your set up and hp goal. This is what they did for me and I am more than happy. They will work with you. I love thier pistons because of superior ring design, I have never destroyed one therefore they last. I have been beating on my car to death and the pistons have survived everything from accidental detonation to temp well above accidental 1685 degree EGT readings. I don't know what more I can say? Use what you makes you happy is all

 

[94awdcoupe]

I bought a set pistons that had that thin edge like that . cant remember the make. my thoughts were that edge is gonna melt. so I ground the sharpness down till it was thick enough to support some hot combustion. engine ran great with no problems. seems kinda dumb to blame the piston maker. it took all of about 5 minutes to prep the pistons. I am shaking my head with confusion why anyone would install them that way

 

[keltalon]

I bought a set pistons that had that thin edge like that . cant remember the make. my thoughts were that edge is gonna melt. so I ground the sharpness down till it was thick enough to support some hot combustion. engine ran great with no problems. seems kinda dumb to blame the piston maker. it took all of about 5 minutes to prep the pistons. I am shaking my head with confusion why anyone would install them that way

Hey man don't shake your head too much that BB may fall out Nobody blamed the maker for the deep valve pocket. After speaking with cp on the issue i found out that they make all their pistons to the specification of vendors who request them as in the case of these 4g63 stocking pistons. They were made with the idea of high lift cams as well as oversized valves. Therefore I personally worked with them on the set that is currently in the car to my specs and they are super. You did not solve the piston issue by taking the thin metal down to the rest of the piston. the problem with the deep pocket is that it is cut too close to the top compression ring and trust if and when you decide to take your engine apart you will see that although your ran fine the top compression ring will have damage. sometimes this damage leads to piston wall damage as well so the dummy in the end is ^^^^

 

[94awdcoupe]

shaking my head even more after you boring explanation...

 

[keltalon]

shaking my head even more after you boring explanation...

I assume you are happy with your setup right? Then that's all that matters. Enuff said. Enjoy your car.

Sent from my ADR6400L using Tapatalk 2

 

[keltalon]

Just to add to this thread. I found another weakness in the cp stocking pistons. The wrist pin can't handle much over 550 whp therefore the pins needs to be upgraded if you are planning to make high horsepower. check out my findings here. http://www.dsmtuners.com/forums/cyl...on-wrist-pin-post153055943.html#post153055943