What pistons do you guys all use?
- Thread starter SpencerA
- Start date
I've run the lot- stock, kimpex, wiseco, SPI, etc etc.... Many guys will try to tell you to use "this piston, it's the best", but in my experience, most of the aftermarket stock-style cast pistons seem to work fine. As long as your clearances are up to snuff, you should be fine with whatever you choose. Lately I have been running the SPI's for the last several sled builds, and have had very good luck with them. However, their "moly-coated" piston skirts leave a lot to be desired. After a few hours use, take a peek through your exhaust port, and you will find much of it worn/flaked away. Not very impressed with that, but they are a nice quality piston otherwise...
Many many moons ago, when I used to build 90-horse Phazers, I used to swear by Wiseco's. They were the only thing that would take the heat of a fan-cooled sled, and stay together while running right on the edge of lean. However, you had to be very careful on your warm up to prevent a cold-seize, and they would rattle something fierce when cold. I have read that a cast piston, which you can run at tighter tolerances because of more stable thermal expansion, will actually provide more power, all things being equal.
To put it in a nutshell, I'm cheap, and I will run virtually anything that I think is a good deal. Just remember- find out why you needed a new piston in the first place, correct the problem, check your clearances, and ALWAYS warm up your sled before hammering on it....
Many many moons ago, when I used to build 90-horse Phazers, I used to swear by Wiseco's. They were the only thing that would take the heat of a fan-cooled sled, and stay together while running right on the edge of lean. However, you had to be very careful on your warm up to prevent a cold-seize, and they would rattle something fierce when cold. I have read that a cast piston, which you can run at tighter tolerances because of more stable thermal expansion, will actually provide more power, all things being equal.
To put it in a nutshell, I'm cheap, and I will run virtually anything that I think is a good deal. Just remember- find out why you needed a new piston in the first place, correct the problem, check your clearances, and ALWAYS warm up your sled before hammering on it....
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SpencerA
Member
Great info! Thank you that helps
With Wiseco's, your paying for the metalurgy, the forging, and tight machining tolerances. The gaskets that they include with thier kits are pretty nice too. Oh, and you also pay for the name "Wiseco" on the box.... lol
i noticed a little diff in quality of wisecos vs. the stock pistons when looking up their squirts
i mean the undersides. not sure if it really matters in the way it ran though, it seemed to run just as hard with the wisecos, and was very impressed considering the price diff. from stock ones. handy that you get a whole kit too with all the gaskets, but i did have an o-ring failure after one year of hard riding, so i beileve the o-rings are not as good imo. ill buy wisecos again, but use oem o-rings in the heads.
i mean the undersides. not sure if it really matters in the way it ran though, it seemed to run just as hard with the wisecos, and was very impressed considering the price diff. from stock ones. handy that you get a whole kit too with all the gaskets, but i did have an o-ring failure after one year of hard riding, so i beileve the o-rings are not as good imo. ill buy wisecos again, but use oem o-rings in the heads.
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SpencerA
Member
Wow did a google search and this is a very popular topic that has extensive material. I was surprised to see just how many people bash wisco pistons and just how many people were happy with the SPI. What I didn't see much of is people who had modded sleds were using. I'm running 30% Race fuel with a ported motor that I need to have the whole top end done. I hear people say you get what you pay for with pistons but if thats true are Wisco truely better then the cheap spi?
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SpencerA
Member
So after hours of research I came to the conclusion to pony up the cash and go OEM. Not sure if its the best but at least I know I'm not skimping on product.
Last question do I need to order the small bearings for a new top end if mine are ok? I see the kits don't come with them. I figured that was part of doing the top end???
Last question do I need to order the small bearings for a new top end if mine are ok? I see the kits don't come with them. I figured that was part of doing the top end???
If the bearings look like new when cleaned.... I use 'em.
If they show ANY signs of wear, overheating, or debris going through them, toss 'em and buy new.
Ever seen what's left of pistons and cylinders after a wrist-pin bearing comes apart? It ain't pretty. So if you are in any doubt as to your bearings condition, replace them.... it's cheap insurance.
If they show ANY signs of wear, overheating, or debris going through them, toss 'em and buy new.
Ever seen what's left of pistons and cylinders after a wrist-pin bearing comes apart? It ain't pretty. So if you are in any doubt as to your bearings condition, replace them.... it's cheap insurance.
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SpencerA
Member
Thanks Zachmandu I actually just ended up ordering new. I figure whats a extra 40 bucks for OEM. Mine looked great but I'm already in there so figure spend the money.
