i have a 83' camaro that i paid $500 for and i love it. it has a 305 v8 4bbl the engine code is "H" i was woundering how far this motor could be bored over.or if i could bore a 350 to a 400 and not mess up the block to bad with heating and cooling.

 

There are very few blocks around that you can bore more than 30 to 60 thousandsths of an inch over stock -- that usually adds 5 to 10 cubic inchs is all. Its usually done because you have to bore the cylinders about 10-15 thousandths to true them on an old worn engine anyway, so go for the max. Note you can usually only bore cast iron blocks by any amount - aluminum blocks (LS1, 2, 6, 7) can only be bored about 8-10 thousandsths.

People get added displacement mostly by stroking the engine: requires a new crankshaft, rods, and usually new pistons (always reocmmended even if . . . ) >

Example, stock GM 6-liter (366 cubic inch LS V8). 4 inch bore and 3.65 inch stroke - 366 cubic inchs
4 inch bore stroked to 4 in stroke - 402 cubic inchs
4.030 bore (30 over) with 4 in stroke - 408 cubic inches
4.060 bore with a 4 in stroke 414 cubic inchs

I have no idea aobut your engine, there are so many specific castings and all I have lost track. You can probably bore it to 30 or 40 without worry and stroke it to add perhaps 25-30 cubes is all. Not sure where you would check. It would probably be less expensive just to buy a bargain rebult or surplus 350.

 

well if it helps, i have a 350 block, and i just recently learned i was bored 4.060 over, im pretty sure that makes me a 360 cubic inch. the only drawback is it heats up really quick, so if you bore a lot, you g2 have a good cooling system. stroking a motor is what really increases displacement.

 

If you have an engine bored to 60 thousandsth then: yes, it wmight be prolematical on heating, and 2) when and if you rebuild it, you can't bore it any more and in fact may not be able to even true it up.

But blocks are cheap. Get a new one or even better, buy a surplus one that has not been bored and the surplus yard will guarrantee (refund you money if it does not pass magnuflux test).

With cast iron, the metal slowly looses internal casting stresses as it ages. Thus, an old block is actually better than a new one, if it has not been bored or abused or otherwise damaged.

 

just noting, im obviously done with the boring. if it needs to be rebuilt, ill be able to take care of it. i have been working on stuff since i was 8, an old go cart, but i am still all ears in the learning process, but my dad is highly educated, back in his day he had many old cars such as muscled out novas, ford torino, monte carlo, and a 72 camaro. not changing the subject though, this is Lotus's forum.

 

If you want to go over 400 inches, you may want to use the 400 small block and not have to worry about the cylinder walls. The stock engine was not a high performance item, so all the internals and heads should be changed. But, with a stroker crank they can go up to 427" without too much trauma. Don't remeber if they had 4 bolt mains, but they can be added by a machine shop. There is also some starngeness with steam build up in the water jacket unless the proper vented gaskets are used.

 

Aside from the siameze bore(all 4 cyl. walls on each side are conjoined no water passage between them)causing hot spots and cyl.wall warpage, which required the steam holes in the heads, the 400SB also has another inherant weakness in the main bearing webbing which sometimes caused rather catastophic lower end failures. This weakness in magnefied when you machine more stock out in order to install 4 bolt mains.

 

I really never liked the 400 small block, not because of the siamesed cylinders (my C5R has them) but because of the bottom end issue. I'd want 4-bolt mains and solid webbing in anything of that displacement I built, and the 400 is just not the way to to. It was a great block for giving those big Impalas a lot of low end torque and smooth power, but I'd never trust the bottom end for serious power.

 

If you're looking for the power in a small package that will bolt right in the car I say find a 350 and stroke it.

 

Best bet is to put a longer stroke crank in it.