Hang Time 27

I ran the piss out of a 468 with just under 500hp with a '73 two bolt main, cast crank setup for almost 500 hrs turning 5,400 rpm max (often) - no problems............if that helps................

jw454

Hey Waterfoul, or anyone else that might know what the cam specs. are on SuperVs engine. How about your 454, Dyno? I am glad to hear your stock cranks are holding up ,because I will be running stock crank and rods( 3/8 ARP Waveloc bolts , Cleavite 77 H series bearings) probably 4800-5000 rpm

blue thunder

Many of you won't agree with this, but in a mild marine application I like cast components. Reason being cost. I have lost several bbc marine engines, none due to the failure of any rotating assembly part. Most engine failures I hear of (and experienced) are valve train related, fuel supply, water ingestion or tuning. These problems with kill a forged assembly or cast, just the cast will be less money lost.

Yesterday I installed a scat nodular steel cast crank in my port engine. Put one in sb engine last summer when I toasted the mains due to excessive oil temp. Again, nothing related to rotating parts. I asked the engine builder I bought the scat crank from what he thought a good max rpm would be and he said "circle track guy run them at 6200 all the time". I asked him what he thought about 5200 in a marine application and he said "it will last forever".

Dave

Hang Time 27

Dave, what kind of oil temp wiped out those bearings?? Just curious...........

blue thunder

280F. Problem was I had dino oil in which broke down and lost its cushioning ability. I think with sythetics the mains would have survived.

Dave

dyno

BT I agree 100% I've broke alot of stuff but never from the cast parts failing!!

blue thunder

In fact, when I was 16 or seventeen I built my first engine (sbc) and but it in a gremlin. Yes I said a gremlin. Had stall converter, 4:88s, turbo 350, 194 heads scorpion intake, holley and all cast rotating parts. I ran that thing in the upper 7k range frequently and never heard a peep out of the cast assemblies. Didn't take too long to wear out the valve train, but again, not the cast parts. Course, then I lost my liscence for drag racing and had to sell my little rod...
I have been wondering for a long time why these cranks get such a bad rap in low rpm marine applications. I havn't heard of a single failure other than casting defects.

Dave