MadMan@TheWheel

I had a friend ask me a question today that I had no answer to, what would an estimate be for HP rating on a stock 302 roller block with forged internals and a Main Cap Girdle? I have always ran heavier 4blt main blocks so I have experience with those, but no real stock block experience.

Thank you,
MadMan

5.0stanger

They can hold up to around 450 to 500 horse.

MadMan@TheWheel

The block should be able to support close to that anyways. So what good does the girdle really do?

5.0stanger

They say they keep the block form twisting, helping it stay together. If you plan on doing any power build on one of those blocks, I would put one on...wouldn't hurt.

greenstreak9205

the main girdle will help, along with the lower intake, keep the block together after it explodes on ya when you push it past the 500 mark for a while . but some do luck out and have them hold together under more power for a long time, but at that mark (+500) its borrowed time

my77stang

i'd take a wild guess and say if a stock block is good for 450-500 then a girdle would let you grab at least another 100 from it. going to the 351 firing order helps too, cause the 302's like to come apart up front due to the 1-5 firing order.

Steve13380

Im a bit confused with girdles, the turbomustang guys seem to say like greenstreak is saying, do nothing at all to stop the block cracking.

but some big names in the business make them, making me think they do actually help.

has there ever been any worthwhile testing?

luckythirteen13

the girdle will only hold the 2 pieces together when the block splits in half. it will keep the main caps from walking which is good. ive seen pics of a 302 that had a half inch thick main girdle. they split the block and the girdle right in half. i can see how the girdle would cut down on block twist a little but i think if that does anything at all, i will just make the block take the hp your at for a longer time, as opposed to more hp. if you want a stock block, look for an older one such as late 60's or early 70's. more nickle and more metal. the newer blocks have metal missing in places because ford wanted to save money and weight. or just get a mexican block

my77stang

they DO help, they spread the load / force from one main cap to others. yeah sure you can still destroy one, but it'll handle more power and take more abuse before it goes pop.

MadMan@TheWheel

Hey, like I stated earlier...I don't have problems with the blocks I use. Siamese 4blt main block have supported everything I have been able to put to them, but this guy I know did ask a pretty valid question, if the block itself will come apart past the 500hp mark why even bother. Either way it affects me none, I build 4blt main blocks exclusivley.