what is the failure point of a stock block
 

where dose the stock block let go due to too mutch power? what brakes, i know the ford guys split them down the center do the chevy blocks do the same?

I know the ford guys split the block between 450-550hp. A solid 4 bolt block should be good to well over that. I've never heard of the block splitting on a chevy, its usually something else that goes first.

so if i build a awsome lower end how much power will a converted 2bolt - 4 bolt block take

650-700... if the block is solid and a higher nickle content block and not a grey metal block... this will happen with the best internals you can find and if yoru only really turning 6500 or less for a max rpm... rpm at those hp levels tends to be the cap and crank breakers...

my plan was to use a 1987 block with scat crank and h beam rods with a set of blower pistons then hit it with about 12-16 psi of turbo charged boost with a set of afr 210 heads

id say your going to be very close to what that motor will handle.. cam it and size the turbo appropriately to produce peak power for 5500=6000 rpm thop and u might be ok...

now would the limit in my combo be the lower end or the block i just dont want to sink 1000 bucks in a block and then have it blow all over the track i have never had a problem making the horse power just holding it in the motor Ie stock short block with turbo and dart heads = kaboom

Well proper block prep is going to be essential- i would say with splayed caps on a 2 bolt, your only worries will be cracking the block - which like i said, you have the potential to be close to.

as long as you use great componants, 4340 cranks, good solid forged steel rods, and good forged pistons, you shouldn't have anyproblems... 1000dollars on a bottom end is not going to hold 700 hp...

you're looking at spending about 600-700 on a crank, 6-700 on rods, and about 600 on pistons to get the most out of that stock block.

Make your block the weakest link and you wont have any problems.

i was talking 1000 on the block not the lower end well whats the worst the thing blows and pukes all over the street infront of all my buddys

and if it dose crack where would it

ahhh got ya :)

Block work shouldnt be much more than 500 bucks unless you are having it machined and clearenced for a stroker or having it oringed....

as for where it will crack, the answer is simply the weakest point... possibly through the lift galey or it could be right up the side of the block... the ford 302's all seem to break the same way, but every chevy ive seen break (not many) have been all different.

ya its huge money up this way for block work i hate it i wish i could just send it out bet then shiping kills the savings

but thanks my goal is to get it in the 10's and still be able to run on the street as a daily driver

5.0 blocks crack because the block was lightened and it's not rigid enough to prevent crank flex. What most ford guys don't seem to understand is that you can make a stock block live to much higher power levels by running a better crank and/or reinforcing the main caps.

Most SBC's are similar to the non lightened SBF's (for example the 351's used in the big cars/trucks or all pre 70 blocks), there isn't a particular block failure mode, but usually failure manifests itself in something else leaving the block at an inopportune time. The point that this happens depends more on the parts used in the block rather then the block itself. For example, if your rods won't survive 7500rpm and that is what you're turning to make the power you're making you can eventually expect to see one sticking out of the side of the block. Same deal with main caps, crank, pistons…

At extreme power levels (usually in the 900-1100hp range) people start seeing some odd block distortions, bearings getting pounded out of shape quickly… Other things start failing very quickly due to distortion problems, even if the block doesn't just fall apart, even with block rock, aftermarket steel mains, plugging/filling the deck holes for less distortion… With factory four bolt blocks (especially the 400 truck blocks) you might see oddness like cracked main webbing even at stock power levels.

FWIW, all this is WRT to street/strip use… you'll find the limits of things much faster road racing or anything that maintains high output for extended periods of time

well i got my quote for the block work.

and it came out to 876 bucks

this is the list i gave them

magnaflux check for cracks
install splayed main caps
line bore
bore, hone.
clean and
deck.

ill let you know how every thing gose.