Olds92

Hello,

Just wondering how many max horses could you go with cast pistons? Not saying im going to go to the max with cast, just would feel better knowing what they are good to.

Thanks in advance.

cutlassefi

What's your usage/hp goal?

Olds92

It's going to be a street engine, so nothing too crazy. About 400-450 hp would be the goal.

cutlassefi

KB makes a good hypereutectic piston with a 15cc dish. That would work well in your build.

Jmo.

Olds92

I dont know what exactly makes a piston hypereutectic, I guess the material, but i've heard bad things about them. That they "shatter." Which I believe maybe because power adders are used and those pistons arent right for that. Cast and hypereutectic are two completely different pistons right?

Have you heard disadvantages about them? My engine will not have any power adders.

380 Racer

The only Olds motor I ever blew up, had cast pistons. Valve head (cheap) broke off and shattered the piston @ 6000 rpms. Sent schrapnal through-out the motor.

citcapp

I have been running the KB pistons in my 57 since 2008 no problems. The problems that I have heard about are all related incorrect timing causing pre-detonation. They have tight sidewall clearances and the ring gap must be set up correctly. If done right they will last as long as any other quality piston. My 455 is a 10:1 compression build with Edelbrock heads and run it hard as often as I can get away with it

cutlassefi

Hypers don't like rpms, not a problem with hp or a mild shot of nitrous. That's right from the Sealed Power engineers.

Olds92

Great, thank you for the info!

Vega

Actually im interested in this too. My 455 block is in very good shape and doesnt need overbore and i found a set of used stock high compression 69' pistons and rods in great condition for cheap so i picked them up. Not thinking anything too radical with the build but id be interested in an answer to the thread's main question. I figure if i dont have to bore the block and am running a limited budget a set of good used high compression pistons would be a lot better than dropping $400 on a set of new ones of the same cc and bore. But like i said, its not going to be a very radical build. stock Ga heads rebuilt maybe some head work, stock bore, crank, rods, cast pistons, really just about all i would be doing to the motor is increasing compression (aiming for 9.5:1 or 10:1 if possible) and adding a larger cam

PS: itd be a street motor, daily driver-ish, horsepower is irrelevant my aim is for torque and lots of it. Hoping for 500 and anything above that is icing on the cake

J-(Chicago)

That's pretty funny. I'm looking to do the same thing with some blocks I have here.
But no one will come off a NICE & COMPLETE set of those pistons and rods. I've been finding them in pieces from blown up motors. 1 good rod here, one good piston there. At this rate I'll have to fill the trunk full to get 8 good round ones with no sticky pins.

Vega

Haha, maybe i got a lucky break :P
Tell ya what though, if this set of 69 rods/pistons works out i'll have a set of 72s laying around that id consider up for grabs
Probly better for the rods than the pistons though since theyre moon-crater dished haha

J-(Chicago)

I have plenty of rods with pistons attached. But most are the 40cc moon craters that you speak of. Anything 71-76 has those junks in it.

The 68-70 2bbls were a little better with a 30cc moon crater, but still suck.

I need the v notched stockers, probably about 14-20 cc.

Finding a whole assembled set with nice pins, and perfectly round rod big ends is definitely a chore.

After thinking about those pistons, I think I'm going to hit the kitchen and make a bowl of soup.

Brian Trick sent me 2 or 3, and F-85 sent me 5 of them. Filbilly sent me a bunch of locked up pistons with hammer and screwdriver marks/chips.
The bore gauge is telling me to keep looking though.