[Half-Inch Stud]

Originally Posted by Stan Weiss

Isn't the I-6 bore size the same as a 350 Pontiac V8 Stan

. YES.

Ought to get to 400 Piston size, and actually the SBC 400 slug from sealed Power can be had 4.18" Bore ( thats 455+030 ) and lighter than the Stock OHC6 Slug.

The 4.18" Overbored OHC6 would retain the 7500 rpm capability.

Has anybody SLEEVED all six OHC6 Bores for 4.15/4.18.4.21"

[LM93]

Originally Posted by Half-Inch Stud

. YES.

Ought to get to 400 Piston size, and actually the SBC 400 slug from sealed Power can be had 4.18" Bore ( thats 455+030 ) and lighter than the Stock OHC6 Slug.

The 4.18" Overbored OHC6 would retain the 7500 rpm capability.

Has anybody SLEEVED all six OHC6 Bores for 4.15/4.18.4.21"

Do you think hypereutectic pistons are good enough? I'm concerned about them surviving any preignition and detonation I get while trying to get a good tune once the engine's been assembled.

[turbo69bird]

Originally Posted by LM93

Do you think hypereutectic pistons are good enough? I'm concerned about them surviving any preignition and detonation I get while trying to get a good tune once the engine's been assembled.

Why let it detonate set it up fat as hell and lazy on timing . Then back into it. Shouldn’t ever go lean if you start wayyyy fat and lazy

[Half-Inch Stud]

Originally Posted by LM93

Do you think hypereutectic pistons are good enough? I'm concerned about them surviving any preignition and detonation I get while trying to get a good tune once the engine's been assembled.

Dunno about hypereutectic (high silicon AL, but theses days aka CAST). i always use Forged slugs and they hold up. A breached headgasket (in 2002?) caused a warped slug-top at the leak.

[scooter1966]

The big thing you probably need to worry more about is head gaskets. You can use the factory rods with some ARP bolts , forged pistons, same as the Chevy 6. Rebuild the head and have a good tune. I so far have only run pump gas to about 15 lbs safely, just over that I did pop the head gasket. Replaced the gasket along with head studs. Car ran 9.42 @ 76.15 in the 1/8 on some old tires I got off Craigslist, spinning too damn much. Using a 1 barrel head will have your compression ratio good for the turbo setup, there is a document somewhere on the forum that shows the different ratio combinations with the heads available.

[mgarblik]

Originally Posted by scooter1966

The big thing you probably need to worry more about is head gaskets. You can use the factory rods with some ARP bolts , forged pistons, same as the Chevy 6. Rebuild the head and have a good tune. I so far have only run pump gas to about 15 lbs safely, just over that I did pop the head gasket. Replaced the gasket along with head studs. Car ran 9.42 @ 76.15 in the 1/8 on some old tires I got off Craigslist, spinning too damn much. Using a 1 barrel head will have your compression ratio good for the turbo setup, there is a document somewhere on the forum that shows the different ratio combinations with the heads available.

I think the head gasket situation could be dealt with. It is iron, thank goodness. ARP head studs or similar could be used. Clark, Flattout, Hussey or others could make a copper gasket. You could o-ring the head and block if copper alone won't get it done. Also, Cometic will make a multi-layer steel head gasket for that engine. These are not low cost solutions, but when working with a unique engine platform and trying to make big power with it, the costs do ratchet up exponentially. I build some high HP supercharged Studebaker V-8's for drag racing and endurance road racing and deal with similar issues. High HP, unusual engines are not for the weak of wallet.