boosted91crx

I have used many different piston brands in the past and cp has always been a favorite of mine, however i got a good deal on a set of new wisecos, so i decided to research them and see how they stack up. if your reading this you also probably did a search and if you read all the threads like i did you probably found where a few tuners had mentioned that wisecos had failed while on the dyno. well this of course worried me so i dug deeper, it turns out the failure each time was the wrist pin lands separating or breaking off the piston body it self. every one automatically was blaming the fact the piston has less mass in the wrist pin land area however i wasnt so sure that was the whole story. so i called a wiseco tech and talked to him about these failures, turns out he knew exactly what i was talking about and unlike some companys did not try and use smoke and mirrors and blame it on the builder or the tuner ect, it seems that the standard wrist pins are unable to stay true under high hp situations. the exact hp rating is hit or miss but they generally claim that for a B series piston absolutely no more then 600 hp ( crank hp ). what happens is under high loads the pin will flex the pin trys to go into the shape of a U but the wrist pin lands stop this and in doing so they take stress not unlike the stress you use on a pencil when you snap it, couple this with the fact the pin is now trying to bind up from no longer being true and the wrist pin lands can snap away. for this reason they offer a heavy duty pin, the hp rating they give the b series pistons when using these pins is over 1000. the only down side i see to using these heavy duty pins is they are a bit heavier, the standard ones weighed in at 85 grams and the heavy duty was more like 108, this is a 22 gram difference. the 84mm wisecos with the default pin weigh in at 356 grams and the 84mm CP pistons with standard pin weigh in at 390 grams, so the good news is the wisecos with the heavy duty pin are still lighter then the same size cp with default pin at weight of 379 grams. below are pics of the standard and default wiseco wrist pins so you can see the difference and also in case your unsure as to which ones you have.

Muckman

iTrader: (2)

Do you have access to a CP wrist pin? They are no where near as thick as the "heavy duty" Wiseco pin. They look more like the original Wiseco pin.

boostedEF91

thats a good write up

swapit

i had the heavy duty wrist pins in my wiseco and they still wore out the wrist pin gland in the piston at 1-dyno session and the 3rd track pass heard a tapping noise and i took the entire engine apart and found that.I got lucky as it didnt break but it ruined my wrist pin bushings in my rods which i shipped back to pauter and they replaced them and mag the rods too.i just dont like they arent a full skirt like the cps.I think the heavier wrist pin makes it worse on the gland area of the wiesco giving the rod more leverage to work the gland till it wears it out.I just wouldnt use them for anything over that 600hp range.I have built many motors using them mostly allmotor but i tried to save some money to put elswhere but ill never do that again...just my .02

boosted91crx

yes and i did compare them they are the exact same thickness, however the CP are .25 inch longer.

boosted91crx

that is a stroke of bad luck sorry to hear. i did some digging and it turns out that other cars like subaru and others use pistons and wrist pins in particular that are much heavier yet.

Muckman

iTrader: (2)

To be clear - CP pins are the exact same thickness as the standard Wiseco pins.
Great thread!

BlakeJ53

iTrader: (1)

This depresses me. I just put wiseco's in my new motor the shop said I didnt need upgraded pins. Looks like I wont be shooting for 600WHP anymore.

tepid1

It's very dependant on the tune too.... Don't change your project based on people's opinion....

BlakeJ53

iTrader: (1)

I think its a good reason! I dont want to have my motor finished and then it blows because I got a weaker piston when I could have changed them for better ones to begin with.

b18_P

good info..

boosted91crx

I agree lets keep the thread as i originally started it, with facts and not opinions.

in my research i came across a bunch of people who went past 600 on the standard pins. but the small few that had the pins fail was enough to make me dig deeper. I know a good tune is part of it however both examples of failure was reported by some of the most respected tuners on here.

i mean to be fair neither tuner built the motors and for all we know the people who did followed wisecos standard PTW recommendation of 25 thou, as we all know thats a little tight and perhaps at the higher HP levels it made more of a bind. either way wiseco was very clear that they do not suggest going past 600 on the standard pins, i asked how much of a cushion they factored into that number and they said no cushion just dont go past 600 on them. heck even the DSS admitted to me that they factor in as little cushion in their axle ratings so if wiseco has no faith in their pins past 600 i wasnt about to second guess that.

narfdanarf

I don't understand why anyone would buy wiseco's unless you just wanted something really lightweight.

HiProfile

For what it's worth, you can get "custom" Wisecos. They can be ordered beefier than off-the-shelf pistons, not just the wrist pin. Considering that OTS Wisecos are cheaper than CP's, it makes sense that you get what you pay for.

One thing I don't like is how everyone tried to turn a blind eye to the CP failures a few years back, then swept it all under the rug. CP originally did not grind away that thing section on the outside of the intake reliefs, and on SEVERAL motors people had issues with that whole section melting away. Lo and behold, they changed the design and now grind it away, despite blaming the builders/tuners for excessive oil blowby or bad tuning. They denied the redesign was to reduce failures, despite the fact failures from that problem dropped to almost zero afterwards.


My point being Wiseco is still a great piston IMO, and if you call them, also great people to talk to. They also have had one of the best & consistent skirt tapers on the market for years, if you look at some of the decades-old and recent magazine comparo's on pistons. CP on the other hand, has only been around for a fraction of the time, and did nothing for those people who melted pistons, except tell them to get a better tuner, or break in their rings better.

narfdanarf

If you buy CP's from a stocking dealer they are the same price as the average wiseco.

HiProfile

Do you know if those dealers have all the specs for their pistons? The CP website does nothing but list generic compression ratios. Their pdf catalog doesn't either, unlike the Wiseco catalogs that list everything. It's very annoying if you're not building a perfectly stock motor, and try to find what your CR will be.

The the only reason I may not use Wiseco's in my GSR build is because it's either 9.9:1 or 8.7:1 - nothing in-between. I thought of using CP's, but w/o data my compression could end up worse.

swapit

yes on cps at a 81mm or 81.5mm bore i take an file down the valve relief because its so thin and sharp that it could cut you and they crack and can fall into the cylinder.
I always set PTW for any piston on a turbo motor .004to.0045 allmotor alittle tighter.My tuner was jeff evans also.But i will not ever use them again unless its low hp or allmotor just from my own experience..
And you can order wiseco custom that dont have undercut skirts.

tepid1

There is a key statement right there.

My custom Wiseco's designed by Brad from RLZ; set me back about $700. Everything is different. From a custom dome to a one of a kind sideskirt to a custom designed gas port layout to a set of tool steel 220 wall pins....

You get what you pay for....

narfdanarf

Since we're just throwing out random stuff about our purchases, my CP's were 560 with tool steel pins and gas ports.

swapit

i think endyne rollerwaves are made by wiseco too...im not sure but manleys pistons look like wisecos too but are alot stronger lookin then shelf wisecos and just as cheap built 2 850hp+ motors and still going strong.

boosted91crx

little added info , motor is running and dynoed, i set the PTW to 35 though and it sounds perfect. made 550 on pump gas 21 psi

swapit

^^great no get it to ETOWN for tomorrow..lol

01DC4

iTrader: (3)

great thread im about to start a 800hp build and this is very useful info, so after reading all this what do you guys suggest for a high hp motor?

boosted91crx

we are having a big import get together at beaver springs dragway tomorrow i will be there for sure back on topic.

o1dc4 you just read all the data, we are trying to keep this thread about facts and not as much about opinions, if you are going for over 600 and decide to go with wisecos make sure to get the heavy duty pins to be safe.

01DC4

iTrader: (3)

true i got that part, so off the shelf cps are good for 600+ with standard wristpin? and going the wiseco route HD wristpins are recommended along a full side skirt?