anthros

Hi everyone, i just finished ripping down a 69 302 engine down to just the block. the block/engine looked great, not bad cylinder wear, no scratches, cracks, or anything looking out of the ordinary. Now for my plans and questions. I would like to half fill this block, then take my 347 kit ( forged 3.4 crank, forged 5.315in H beam rods, forged aluminum +.030 flat top pistons) to the machine shop to get it magnafluxed, sonic checked, hot tanked, bored .030 over, internally balanced, cam bearings, freeze plugs, ect. Get it back and do main studs, main girdle, windage tray, HV oil pump, 7 qt. pan, solid roller, rocker stud girdle, slap a set of ported 185cc heads on, custom cam, parker funnel web intake, 650-750 carb.

Now here is my question, i would love to juice the engine to, asuming a competent dyno tune how much flywheel HP, or RWHP does everyone think i would be safe to push it to with the juice? No i dont want to buy a dart block to make 1000+ Hp, just looking to get as much HP as i can on this healthy 69 block.

anthros

bump

aode08

First thing is give the block to the machine shop to bore to the min specs to clean it up.

Most 302's clean up .020 over.

Second, dont fill you block with nothing but coolant.

w8less

how big of a shot? what kind of compression?

anthros

compression will be 11.03 to, i will be half filling the block to help with rigity at the bottom of the cylender skirts, and to help with strength in the main webs. and i dunno what shot, the shot i use will be whatever is needed to bring my rwhp up to what everyone thinks this block will hold ( everyone says it will handle 500 rwhp, and it dyno's at 400 n/a then it will get a 100 shot... ect.)

w8less

have you ever heard of cryo freezing a block? there was a couple ppl on the corral who swore buy it. i asked about it at the local machine shop and they did say that it would add some strength to the block. i think with the things you have mentioned the block would handle a 150 shot

anthros

i have heard of cryo freazing, i have had it done to a few of my long range riflle barrels, i dunno where i could get it done though with something as big as a engine block.

67mustang302

A lot of it will depend on how much power the 347 makes n/a. Depending on heads/cam you may max it out without juice, or you may not.

anthros

ok, ty. My question is how much power is considered maxed out for a 69 302 block? not how to max it out, i can achieve that on my own.

67mustang302

With a good tune, 500-550 flywheelis considered a safe maximum range for 302 blocks. It's also going to depend on how well balanced the assembly is and the weight of the pistons/rods. The longer stroke of a 347 is gonna put a bit more stress on the block, lighter components with a better balance and tune will hold more power reliably than heavier stuff with a crappier tune and balance. It's also gonna depend on whether or not you need the engine to stay together, if it's going in a driver and you can't afford to have it break, then I'd keep it to the 500ish range to be safe, if it's going in a weekend car and you build it with better parts/qaulity, then you can push more and not have to worry as much.