69POLARA383

OK, things are getting just a bit overwhelming for me...First time rebuilding and need some help figuring out some things. First off, I just bought a factory steel crank turned .010 with the factory 3.75 stroke, I need new rods and pistons but dont know how to figure out what exactly I need. I don't know what rod length or what size pins or anything. I also need to know how to figure out what type of piston I need. Last is the dang cam shaft...and push rods too, lol.

I want to run about 100-200 shot of nos, so far I have 1.6 steel roller rockers on p&p'd 906 heads that have also been milled, high vol oil pump with 7qt pan & hemi pick up, lt headers, torker intake, and prob gonna run double pumper carb with mech fuel pump, behind it all is fresh rebuilt 727. Not going to bore out the block, walls look clean so stock piston size is there. Want to run something that isnt going to break down after every few runs down the strip or at the stop light, not trying to max anything out, but want bigger and badder than normal.

TVLynn

DID you have someone measure the cylinders ??? If you are going to run 200 hp nitrous YOU need forged pistons and a re bore of the block for the new pistons, and aftermarket rods... and you should have an electric fuel pump.
You need to talk to an engine builder and a trans builder If you hit a stock converter with
5-600 hp on a regular bases it's going to blow up

69POLARA383

Having a converter built, shoulda mentioned that too. Should the rods be stock length or can they be longer? I read somewhere that side load has something to do with this and it depends on rod length/pin size or style? Not too sure but I figure that if I need to bore min .030 would be the way I would go. Now being that my heads are open chamber but still milled, should I go with a dish forged piston to reduce cr a little more for the nitrous or would I be ok with a flat top?

Coronet 500

I suggest getting one of the "How to Hot Rod" or "Performance Big Block" books out there, alot of good info and answer many of your questions. A wise man once said "Fill your library before your tool box".

duster_066

+1^ big time.

No offense intended. You are wanting to build a custom hi out put motor, and you don't know what you are doing. That's a recipie for big disappointment. Get a good book that walks you through the build you want, and do everything it says. Find a good machinist who will talk shop with you, and who knows what you are trying to do. He'll be your greatest asset. Go slow and get it right, and you'll be very pleased. Miss one small detail...

PK1

I triple the last 2 suggestions... There is a ton of experience on this forum and most are very humble and only offer stuff to prevent you from doing things the wrong way. We all did stuff wrong and i wish there was someone to save me form wasting on more than one occasion.

Piston size and material selection, final bore finish and size, deck finish for an MLS gasket vs. standard gasket, ring gap, cylinder pressure, etc.... At 600 hp you will only get one shot ( no pun intended). Anything that is wrong is going to do catastrophic damage.

Start reading everything. I bet there is an old engine masters out there with a 440 pushing 440 hp. That would be a good starting point on a project to copy.


Don't let us rain on your parade. Get this motor done and enjoy it, just change the approach so it lasts for a little while for you. Good Luck!!!

robinsonwr

Well, that is a deep subject. You can successful run a 200 shot on hyper-pistons but 2618 forged would be much more reliable. Rod length and pin size are really preference if you ask me. I am currently building a 440/512 with hydraulic roller cam, Stealth heads, and dual plane intake. The rotating assembly has 7.1 length rods with .990 pins which is chevy stuff. Reducing the pin size deducts weight in critical area. The factory 6.768 rods are great for any build. I agree with other that you may want to follow a proven build and leave the stress behind.