Inliners International Forums General Discussion Hi Performance Hypereutectic pistons for 230?

Hi, long time no post from me. Virtually no progress, other priorities in life getting in the way. Anyhoo...

I have tried to look for hyper pistons for my 230, but no luck so far?? Anyone have a source that won't break the bank?

Thinking of mild turbo setup somewhere down the road after a basic stock rebuild (added some tweaks to prepare for more power later, just cause everything was opened up)

Jan Andersson, VA

Find V8 283 forged pistons. Direct fit. Easier to find.

I'll look into that, but what I've seen so far, the price is about 2x.. or more

Thanks

http://www.ebay.com/itm/Keith-Black-283-...00f2e69&vxp=mtr

MBHD

Greetings . . .

I am an old school kinda guy . . . but I am curious about why you would be interested in a high silicon 'cast' type piston if your plans include a turbo.

Modern forging techniques require way less silicon and produce a piston that stands up to compression forces and combustion temperature far better than 'hyper' cast pistons from the days of yore.

The Ross site discusses the particulars in detail:
Ross Pistons

Hypereutectics was a compromise when construction was limited to casting. Buy introducing silicon one could machine the cast slug to a tighter tolerance - since additional silicon limited the expansion of the piston in the bore. The trade-off was that the piston became more brittle so knock and chamber pressures needed to be controlled - since stress cracks would simply run wild through the silicon channels in the alloy.

regards,
stock49

I agree stock49. For years hypereutectic style pistons have been "hyped" up(no pun intended) as being something they are not. And many people have bought into that "hype". They are no better than ordinary cast pistons, and not desireable for the use you are seeking them for.

Yep, the hyper pistons are brittle.

Stock the Syclones & Typhoons use the pistons.

Get into desent detonations & they will blow apart very quickly.

I run up to 26 psi in my 100% all original longblock in my Syclone. (This is with hypereutectic stock pistons) Dynoed @ 386 HP & 560 ft lbs of torque @ the wheels. Older turbo & less boost.

You have to have the tune correct, or it will let go very quickly.

The problem I see when guys run forged pistons @ times is the piston to bore clearance needs to be looser & will give some piston slap which will give false knock, and will retard the timing pulled by the E.C.U.

You can run cast or hypereutectic pistons @ low boost levels, but they cannot tolerate much detonation.
Forged pistons can take some more abuse from detonation, but even forged pistons will let go if the engine is detonating & you do not get out of it.

MBHD

I would like to respectfully argue that the hypereutectic pistons will work just fine and will have the following advantages:

less expansion for quiet operation
great wear properties
lower cost

For you street engine with a future "mild" turbo boost hypereutectic pistons will work well. In fact they would be my choice for your engine up to about 300 - 320 HP, well beyond what a mild boost will get you.

I plan to use them on my next street / strip 300 build for our #1 Anglia.

#1 reason for hypereutectic piston failure:
"What end gap did you use for the ring?"
"4.000" pistons get .016", like I always do"
"Did you read the instructions?"

"....what?"

I appreciate all the input, thanks.

I don't claim to know everything but I've built several high performance engines before.. I'm a master tech and race car builder and mechanic, used a lot of time pushing the envelope. Done it for 20 years or more, just not these engines.

I am not after several hundred horses. I would imagine 250hp would be sufficient, focusing on increased torque and "ease" of keeping up with traffic and hills. Kind of having a little extra torque on reserve, but behaving like a bone stock engine at light throttle, with good fuel economy and feeling, behaving very much like a stock stock engine. In other words, still a pig
Plus I do not race.... it is a street driven grandma car. This engine is basically going to be a stock rebuild with a low boost turbo for all around comfort. It will be my "backup" engine if and when I get a bigger one done. I've got my CR set at around 8:1 and I will probably run 8psi of boost or so. The block is STD and I won't be boring it oversize. It was honed maybe 2 years ago when I put new cast pistons in it. It leaves a hair more room for piston expansion, and I'm considering Total Seal 2nd rings to minimize blowby under boost if it were to happen. (It does not have blowby problems now). That should do all I need this engine to do for me. I just want it to move along effortlessly in traffic and stay together forever.

As for detonation, I don't plan on allowing any... hypers or forged, it does not matter. Detonation is baaa-aa-aad.


I will most likely build another engine for the same car, based on a 292, which will be a whole different story. I have a lead on a running 292 already.

I was looking to use hypers because of cost and better compatibility with turbocharging compared to stock cast pistons.
As was already mentioned, the thermal expansion is better controlled with hypers.

Forged pistons are out of my target budget, I'll use those on the big engine. I just can't have everything, you know how it goes.

Interesting perspective FTF . . . and perhaps I am misinformed here.

I have always been under the impression that hypereutectic alloys were created to allow for tighter machining tolerances over eutectic alloys in like-for-like 'cast' processes:
KB Silvolite
for the benefits that you have listed.

But I am also under the impression that forged pistons and cast pistons have very different thermal properties such that given the same aluminum alloy a forged slug can be machined to tighter tolerances then a slug cast from the same material.

Found these: http://www.ebay.com/itm/57-67-Chevrolet-...ssories&vxp=mtr

Any comments welcome.

A Buddy of mine, Blaine Ramey runs this Mustang Super Stocker in NHRA competitiuon.

Supercharged Modular V8 5 liter engine
Mid eight second quarter mile times
just under 1000 HP

HYPEREUTECTIC PISTONS

As Charlie Umpenhour says, "'nuff said."

The guy who designed most of the KB Silvolite pistons also builds some pretty hot McCulloch superchargers. He runs the hypereutectics he designed.

I just checked with Blaine. He now uses 9.6 Mahle forged pistons in his 1100 HP, 330 ci engine with 27 psi boost. But I still maintain you'll love the hypereutectic ones for your application.

At less than 10psi, I think I should be fine...