[glhs#116]

I'm probably needing new pistons and rods soon since I have this big gouge in #6 that will probably require an overbore. I've read quite a bit about how much advantage the newer engines get from their thin ring packs and shorter skirts. Friction is reduced a lot and sealing is improved. Wear is lower too.

With all of this in mind I figured it wouldn't be hard to find some pistons for my rebuild with a modern thin ring pack. But looking in the usual palces like Butler and Summit I don't really see any such options. Where should I be looking?

Sam

[graygator]

I've looked as well. The only ones I have found are the Mahle PowerPak pistons with a 1.0 mm/1.0 mm/2.0mm ring pack. But they have a compression height intended to use with 6.8" rods, so basically for a stroker kit. If you do a search for 'pontiac stroker kit mahle pistons', you will find a couple sources using Mahle but they don't specify the ring package. I have not used any thin ring setups as yet, but it sure seems to have advantages. I'm very interested to see the coming comments and to see what people are using.

[mysticmissle]

i did a 455 with the ls style ring pack, not sure how much power the rings added but made enough power to split it up the middle

[Sirrotica]

Paul Knippen is a dealer tor Racetec pistons as well as an engine builder that does a lot of Pontiac Stratostreak builds. I would contact him for options and advice. Racetec will build a piston about anyway you tell them to.

He posts here often, and also is on Facebook:

Link to Paul K on PY forums:

https://forums.maxperformanceinc.com...r.php?u=134156

People that have purchased from him were treated fairly on pricing from past posts.

[Lee]

I've also used RaceTec pistons with the metric rings a few times.

Biggest advantage is that I see, is they allow a neater packaging of the rings, when you stroke the motor and use longer rods. Keeps the wrist pin from overlapping the oil ring groove, which requires a support rail.

[glhs#116]

Ya. Mine's the original 71 455HO motor with a real Pontiac 455 crank in it so I'm really looking for a piston that will work with a stock style 6.625" rod. I also like the idea of some decent gas porting to keep those rings seated. Guess a decent skirt coating would be good also, right?

Basically, I like the idea of a lightweight low drag efficient piston that should
* Lighten the assembly so the car revs happier
* Lighten the assembly so the components are less stressed
* Lower drag for free horsepower
* Lower drag for cooler running
* Lower drag for free fuel efficiency

As long as it's not stupid money I feel like it's the direction I want to go.

Sam

[Formulajones]

It can be done with the stock crank and rod length, just have to order custom.

The last 455 I did (stock rod length and stock 4.210 crank) had a custom piston setup, was for a 72 455HO build actually, with a slight dome to raise compression so the heads didn't have to be milled excessively, and had the small ring package. I think 1.5/1.5/3mm. I can't remember the piston manufacture off the top of my head.

In fact everything I've built in the last few years has been small ring packages. Some of them had small ring package pistons available right off the shelf as that is becoming more the norm.

[tom s]

I think I have bought about 4 sets of Autotec from Paul.Great source.Tom

[Rar_421]

Originally Posted by glhs#116

I'm probably needing new pistons and rods soon since I have this big gouge in #6 that will probably require an overbore. I've read quite a bit about how much advantage the newer engines get from their thin ring packs and shorter skirts. Friction is reduced a lot and sealing is improved. Wear is lower too.

With all of this in mind I figured it wouldn't be hard to find some pistons for my rebuild with a modern thin ring pack. But looking in the usual palces like Butler and Summit I don't really see any such options. Where should I be looking?

Sam

I haven't gone through their complete offerings for Pontiac,but DSS racing has alot of Pistons for Pontiacs ,I think they might be the only ones offering a off the shelf forged 350 piston

[jerry455]

I got a set of pistons from Diamond, and they will make anything you want. You get a couple of changes before you pay extra. I don't remember the exact price as it has been a couple of years.

[glhs#116]

Diamond have a nice catalog online and seem to stock some Pontiac items as well as have a pretty comprehensive custom order form. Not the cheapest of course.

Seems weird how hard it is to find information you'd think people would want to know. Like piston and pin weight..

Waiting on some pricing info from Racetec. They responded but asked for more info.

Sam

[steve25]

Doesn't JE pistons have a formulation for there forged pistions that has a nice low expansion rate, yet is not a hyper ?

[slowbird]

Originally Posted by glhs#116

Diamond have a nice catalog online and seem to stock some Pontiac items as well as have a pretty comprehensive custom order form. Not the cheapest of course.

Seems weird how hard it is to find information you'd think people would want to know. Like piston and pin weight..

Waiting on some pricing info from Racetec. They responded but asked for more info.

Sam

Good luck getting pistons from Diamond, before covid they were pretty good, now they horrible to deal with.

[Formulajones]

Originally Posted by steve25

Doesn't JE pistons have a formulation for there forged pistions that has a nice low expansion rate, yet is not a hyper ?

Not sure Steve, I use JE in one of my engines here and don't recall mention of differences in material formulations. I built that engine about 6 years ago, don't know if that's in the time frame of your question. I can tell you it was a pretty expensive piston though, back before all the price gouging.