Search turned up nothin... Im trying to decide between a cast nodular iron crank and a cast steel crank for my ~420hp smallblock. The two are around the same price, the steel crank seems like a more logical choice, but Ive heard bad things about the quality of Scats products. Anyone with experience or opinions?

 

after what i read, i think id still get the scat crank, but i would have it double checked by a good machine shop to make sure its not only the right size, but is round where its suppost to be round....

 

for a 420 HP goal either should handle it no problem... this may be completely irrelevent im not sure, but my friend ordered a 347 stroker kit for his 5.0 and the kit is rated to 750 HP, and came with a nodular iron crank... and i know LT1's had nodular iron (im not sure if they are balanced differently though) and i know vortec truck blocks have nodular cranks, im not sure what other motors do, but anyways you might consider a used crank and just have it turned i dont know if it'd be cheaper or not

 

I don't about that price, but I bought a used cast crank for a hundred bucks from a crank shop. Took it and grinded off any stress risers, than had the oil holes cross cut and chaffered. Topped off with a nice balance job, and dropped into a 400FP motor that loves turning 6500rpms.
Total cost was 250 bucks, and is a lot easier to swallow if it cracks in half form the stress, than say a 600-1000 dollar forging.
Than again, I would even attempt turning 7500 or more with a casting.

Ron

 

without digging out a metallurgy book i'd say nodualr is the better crank. i wouldn't use a scat product, but that's just me and i don't know much

 

id like to rephrase what i said.....


id get the scat crank and have it checked..... but only if it was one of their stroker cranks.... ie, id rather have a 415 then a 406....

but if its regular stroke, id just get a good used crank.

 

Both standard cast cranks and nodular iron cranks are CAST and they are made of IRON. Only forged cranks are steel.

I am not the guy to ask about the specifics but I got into a long debate about this on another board and this was the final answer.

Please note that the cast iron material used in a crank is way way stronger and better than say, a cylinder block. There's a TON of technology behind modern cast iron cranks (standard or nodular iron). I think that the nodular iron ones are probably stonger/better but that's just whisper-down-the-lane information.

I've personally pushed cast cranks to the point I thought they would break- and they never did. They're strong little buggers. Extended high RPMs are not their strong suit, however.

 

Scat and Eagle both make 80-60-06 'cast steel' cranks. Theyre very reasonably priced so they were an option for me, but I just went ahead and bought a new nodular iron crank from Speedomotive.

 

yep cast steel is very common metal, just like cast iron