383is4me

i am going for some ***** to the wall torque out of my 383 i am going with the eagle h beams 6 inch, srp flat top pistons. whatthe hell do i do for the crank. i have all the bolt ons and the cam will be custom ground when i see what i am working with

Ricktpi

Scat 4340 forged crank would compliment your piston & rod choices. Unless you are making lots of power, you probably don't need H-beam rods. I-beams are lighter.

383is4me

what is too much power i was looking for 500, 500 at fly wheel am i on crack

shaggy56

A forged crank will be heavier than a cast nodular crank like scat or what have you. Those cranks are plenty strong. I wouldnt get a forged crank unless im using a power adder or really pushing the engine hard. Forged cranks are usually used for all out race engines that will be put under lots of abuse and running high rpms. If you notice most engine builders will only use forged cranks when it is a blown application or for full racing engines. Forged cranks are an uneeded expense otherwise.

danzig27

Umm...forged is also excellent for peace of mind. And that means more to me than a few lbs.

shaggy56

I know racers who have been racing on nodular cranks for many seasons with 700 hp with no problem. On the other hand I have heard of forged cranks snapping on less. But these were specific incidents. Nodular cranks that are made nowadays are alot stronger than some of the older original forged cranks that came stock. If you look at most stroker kits come with a nodular crank unless a power adder will be involved. Especially with a the 383 stroker crank thats based off a 400 crank which has alot more meat to it than a normal 350 crank. But idf you want the extra warm feeling by spending the extra cash then do so. If it were me I would only do forged in the situation of a power adder or if I was a full race car driver. This info was taken from a very respected race engine builder.

Mkos1980

iTrader: (8)

I ended up with a 383 stroker package which had the Eagle cast crank , Eagle H beams (dont ask why!!) , Speed pro pistons, rings and Clevite Bearings for 694.00 shipped.

danzig27

That's a pretty good deal. I ended up with Eagle 4340 forged crank, 4340 H beam ESP rods, forged SRP pistons, came with spirolox, clevite bearings, don't remember the rings cause i'm going to use gapless. But it is internally balanced i paid a hair less than $1700

Mkos1980

iTrader: (8)

I thought so too. I picked up my stuff on a package deal from www.gofaststuff.com

92 zzz28

I am not trying to start any trouble, but my Cola 4340 forged steel crank is lighter than a stock and most iron cranks. Not to mention much stronger. But I did first use it in a nitroused engine and now my engine is built for boost...

shaggy56

Of course the 4340 forgings are lighter. But prepare to spend some green.

Mkos1980

iTrader: (8)

I priced a cola and it was around 900 bucks. What were talking about here is a good crank w/o a power aid.

shaggy56

Heres is some good reading.

http://www.scatcrankshafts.com/newslawone02.html

92 zzz28

****,

I agree with you about iron cranks. There are many racers who have to run stock iron cranks in racing classes and are making lots of power and turning fast times. Also for a street engine, go for the iron, it will last forever unless you abuse it.

I selected my engine parts based on building a solid foundation for what was at one point a NO2 engine. Now it is a blower motor. THe forged crank is overkill for me, but I had the parts already. Maybe a little blown NO2 is in order!!

Later

shaggy56

I wonder why they dont make it out of this. Look at the grades and its cheaper to make.

"Austempered Ductile Iron"

92 zzz28

That's interesting. I wonder too.

shaggy56

I heard from someone that they are using this for crankshafts. Possibly how the scat 9000 is made. Supposedly this advance is fairly new in metalurgy. They basically add silicon and some other elements to a cast and heat it and its tougher than a forging. I found more info from an old hotrod racer about the forge cranks snapping. This is what he had to say.

"Being the victim of a forged crank, I can tell you what I have learned over the years. The forged cranks that Chevy made in the 50's and 60's were forged 'flat' and then twisted. It was usually at the 'twist' where the breakage occured. If you were to look at a crank starting from the back, you have the rear main journals, then the journals for the #7 & 8 rods, then the next main journal. It was right in front of this main that the crank would break. On mine, back in 65, they did a dye penetrant test of the crank. Being that the hairline crack was where it was, it was not detected by the machine shop. While I was racing a Cobra, like a 55 chevy with a 283 would beat a Cobra with a 289 - year right, my shifter came lose and I twisted the engine over 7500 (tach stopped at 7500 so I don't know where it went to) and the crank snapped. When we tore it down, you could see where the dye had gone into the crank.
There has been a debate since the 60's over forged vs. cast cranks on the street. Just remember, most of the 283/327/350 from back in that period came with cast cranks. Ford did not use forged at all. And if my somewhat faulty memory is correct, very few manufacturer's used forged parts except in the ultra hi-po engines. All of the HOT ROD material from back then pretty much said that under 500 HP and cast was OK."

He was on one of the more famous corvette forums. I was also reading how cast cranks make for better dampening than forged.