Hot Rods .125 over 283 pistons

you can use what ever block, but you can't hide the breather in the back of the block. I have bored a 283 60 over had one sleeved to get all eight back to stock and building one with 4 inch bore to use stock 327 piston. I just don't want to be the same and use a crate 350

 

Quench distance (the distance from the top of the piston at TDC to the flat of the chamber) for an SBC is generally accepted to be in the .035" to .045" area for best detonation resistance. My stock sbc engine is .025" in the hole, so I use the Felpro 1094 steel shim gasket at .015" for a .040" quench or squish if you prefer.
My hot 383 sbc at 11.3:1 with aluminum heads runs a tight quench with pistons out of the hole .007"and a .041" composition head gasket for .034". Runs great to 7K rpms. Pistons don't hit the head.

 

I understand what you mean. The engine in my 57 Chevy is decked to zero [relying only on .038" gasket thickness]
When we purchased replacement "rebuilder" pistons they were shorter in compression height. So we had to cut .055" off the deck to come up to zero. Shorter deck or Thinner gasket still alters manifold fitment.
With the extra 67 inches and stock OEM compression height pistons gives us the situation where a mild skim off the heads and/or deck should be enough.
I would rather spend $$$ decking the block [if it needs skimming anyway] than chasing for specialty .015 gaskets in New Zealand.
I don't want to go over 9.5:1 because I'll be using a short duration cam a for low down power curve.

Common sense would be to simply use a carburettor conversion on a stock L98 with the 58cc Alloy heads and roller cam.[not a 283]

 

Better to use gaskets to adjust quench and keep deck shaving to a minimum.. Decking causes weakening of the deck. How much is too much? I have no idea of availability of gaskets in New Zealand, but the 1094 is a very common gasket. You might check it out. I'll bet that a couple more tenths of CR with good quench gives better detonation resistance than less compression and more quench distance.

 

i'm just trying to build it like they would back then. this is the HAMB, isn't it?

and in my area, they would have went to bob and had him build them a hydro to put behind it.

sigh...what happened to the hamb i used to know? a 350/350 it is then.

 

Follow your dreams. As has been said before, it's only a matter of money. If you follow the cheap and easy route you might be kicking yourself later. Build it once, the way you want, and have fun with it!

Sent from my SM-G892A using The H.A.M.B. mobile app

 

Back then I remember a friend rebuilding the same small block more than once. he went conservative on the overbore. Engine lasted through 3 vehicles. For street use, I don't recall anyone going to a max overbore the first time.

 

i think i'll be long dead or at least past caring by the time it will need another rebuild.

 

I remember quite a few 4 inch 283's running around. Grab a late 283 block and get it sonic tested. Punch it to 4 inch and build it. Stick a big solid cam in it with 12.5 to one pistons and go have some fun. If you need to rebuild it and it needs bored, go get another block and start over. Unless your a car show guy, then mill the piston tops and keep the compression down. But WTF fun is that? If you want to see what it was like back then, then build one like back then! That's the only way you will know. If you have to burn race gas on the street then do it. If of course you got the yearning for it. Just use good parts. When you tire of it, get a 350 and throw in it and show all your buddies that cool 12.5 to one 301 sitting in the corner of your shop. Nuthing sounds like a street high compression solid lifter 301, or 2, coming down the road with those solids singing just right at about 4 grand. Do it. Lippy

 

Spend the money, buy the pistons and do it.

 

Oh and if it overheats once in awhile, pull into the A and W and let it cool off for a spell. LOL