I know it says up to 500HP, but the motor my son will be building will bebetween 500-600hp (just taking a wild guess) I know a lot of items like this can actually handle a little more thanwhat is advertised…but would you think there would be any issues with running acast steel crank? Just looking for somegood suggestions because if I absolutely have to I can upgrade to a 4340 Eaglecrank for an extra $406..but if I can use that $406 to put towards a better setof heads or an EFI unit or good carb I would rather do that. Suggestions please!

Go with the 4340 crank, it's better to build the bottom end the best you can. Eagle only recommends the cast steel crank for 500hp, many people have complained about breaking the cast cranks when pushed too hard.

 

Well I guess that settles that!

 

Made 600+ on a with an eagle cast crank and SIR rod 383 Sbc with two T04B turbos. Had a 4300lb truck into the 10’s back in 2006. Never had an issue and that engine I sold to a buddy and he still has it. Last dyno’d 500hp 535tq with a small weiand blower on it now. Not ideal by far but was cheap and it held up well.

 

I guess I need to decide on whether I want to take a chance with a cast steel crank...or spend the extra money for the reassurance...but then that would take away from the money I set aside for my son and his friend to build the motor. I gave them a $4500 limit on getting this thing going.....they still have to get a trans

 

Buy it once... 4340 FTW!

 

That cast crank will hold more than 500hp if everything else is right. I have a 410 Windsor well over 600 with no problems yet.

 

yea I agree....but then again a 17yr old will be driving it... I know he is a good kid..but im betting if he is out and about and gets a wild hair, he may try to spin it to 24,000 rpm


I remember when I was 17 I borrowed my dads 1976 Olds Vista Cruiser..had a big block in it. Me and 8 of my friends wanted to see how fast it would go. So we drove towards Tahlequah from Ft Gibson The road to Tahlequah its a straight paved road for 7 straight as an arrow miles.....we had it up to about 150mph for at least 5 of those 7 miles....then it just died! We left it on the side of the road so we could go get it the next day, about 7am the next morning my dad woke me up and beat the ever loving shit out of me. Learned 2 lessons during that ass whipping...NEVER run a big block 455 flat out for 5 miles.....and if you do, you better run your ass away from home cause dads gonna beat your shit senseless....I never did THAT again with any of the other cars he owned! :yawinkle:

My son has a whole lot more smarts at his age than I did..but I think im gonna play it safe and just get a 4340 crank!

 

Gonna have to call bull shit on the 150 MPH VCer!

Never happened.

 

Gonna have to call bull shit on the 150 MPH VCer!

Never happened.

How about we just call it the fog of nostalgic memory.

I had my mom's '78 Camaro(305/AT) up to 130 or so IIRC. When I finally exited the highway and hit a red light it was smoking and the lifters were ticking loud as hell.

 

Horsepower ratings on parts are utterly meaningless.

We only use them because you keep asking.

 

I would rather trust a good used forged crank than a cast unit.

By the time you take a cast one and insure its in good shape, you could purchase a good forged one used fresh from a machine shop.

 

what is he going to do with the car? Is he drag racing it and twisting it to 7500rpm every weekend? or is he just cruising it around town and only stretching its legs to 6000 rpm every blue moon. If he is turning 7500 every week do not go cast,if cruising around town and a trip to the track every blue moon ,the cast will be fine.JMO

 

street driving..maybe drag racing on the weekends.... I think I will just go ahead and go the extra money and go forged. I don't wanna skimp on 1 thing and that be the reason it grenades

 

Pay now...pay later, you decide

 

I bought a 3" stroked SBC crank from Eagle with their ESP surface treatment on it. Supposedly rated at like 1,000 hp... I also bought their 6.25" long SIR rods and then realized they rated them at something like 400+ Hp! So I sent them back and got the 4340 H-Beam 6.25" long rods to better Hp match their crank... If I do wind the little short-stroke bugger up to 8,000 rpm, then I want it to hold together!

Take it fwiw..

Oh, the ESP finished crank is beautiful, imho...

pdq67

 

OP- Another thing to keep in mind is that in certain cases, and depending on what you are doing, the forged crank may be both easier and cheaper to balance than the cast crank. By the time you add in the cost of the Mallory metal and the labor to balance a cast crank (again, depending on the build), the forged crank is not much more. Talk to your builder and machinist to get a better idea as every situation is a bit different.

 

Holy Shit, where the fuck you been, brother? :smt102

 

How many times you ever heard of a cast crank breaking? But if you can find one some places sell blem 4340 cranks at a significant discount if you're really worried about it.

 

Ask some fast dirt boys bout them cast steel cranks... They was breaking the rear flange off of em.

 

If the cast crank breaks, good chance collateral damage will hurt the heads you spent extra money on. Spend the money on the crank. JMO

 

You don’t build a good house on a bad foundation so in engine speak your crank and block is your foundation. If those let loose everything else may be junk.

 

my experience with Eagle cast cranks is you may have to dress the journals cause the one we got had too little side clearance on the radius on the rod journals and had to have it machined..

 

Kids will be using this motor and they aren’t even paying for it. You can be sure they are going to beat the piss out of it when you’re not looking

I’d want the added insurance of forged

 

My youngest kid broke his motor "just going 35 down Anza, Dad." The only time that little shit did the speed limit was if there was a cop on his six.

I've had several dads over the years call me about their kids broken motors. None of them ever went over 3K, and would never lie to dear old dad......

If you give a kid 500 H/P, he's going to use it. He is not going to obey any instructions to the contrary........and I don't care if he sleeps on a cross......

 

If you're going to use a factory block, go with the cast. No need in having a crank good to 700hp when the block will shit the bed at 500hp.

 

I assume sbc? Have a eagle 4340 in dad's car along with eagle 4340 rods. Been in there nearly 7 years. It probably bounces off 7000 atleast 10 times every time he drives it LOL

 

If you're gunna use cast, just use a stock crank.....