Crankshaft?

[88bluestar]

First off, let me explain the engine demands. Hobby stock engine, and to some degree budget minded.
3/8 mile dirt track with wide turns so likely not as much hard braking so rpms will only have a slight drop and then right back in the gas.
8.5" tread width American racer kk704 can be used but 2,950 minimum, though if normal passenger tires are used there is no weight minimum.
Max rpms 6500-6700 roughly.
10:1 compression-360 max using a 2bbl rochester, exhaust manifolds required-using LT1 Camaro manifolds likely. Using E-85 fuel.

Looking at cost and strength for cast crank either oem or scat/eagle/etc replacement type cranks.

For this application would a cast hold up for say 15-20 race nights?

[Mark O'Neal]

How the cast crank holds up depends on the abuse it sees.

The Scat Excalibur Lightweight is right up your alley.

They're looking at a 10 to 15% price increase, so don't delay.

[PackardV8]

If the tune is right, the cast crank should survive.

[Mark O'Neal]

And the cast crank is light. Match it with a 520ish gram rods and a sub 400 gram piston

[BillK]

blue,
A bunch of years ago I did a Hobby Stock type engine for a customer that raced mostly at Potomac Speedway here in Southern Maryland. Sounds like a very similar track as what you are on. Engine was almost identical to what you are working with. They ran the car for 3 seasons before we even freshened it up and then another couple of years at least. Never had a lick of problem with the stock cast crank or the stock GM rods with ARP bolts.

[dannobee]

Hobby Stock?

Way back when, we helped out a guy on a really tight budget. He couldn't afford much more than tires, so building any kind of race engine was out of the question. We had a running but high mile core engine from the dealership that we gave him. Told him to buy a set of rod bolts (little did we know he would just take off the pan and change the bolts one at a time). He slipped in a cam, lifters and a circle track pan. IIRC, it was a top 10 car on the local half mile paved oval track and he only came back when he wanted us to do a valve job. Stock lower end everything, although this engine had the powdered metal rods.

[rustbucket79]

I’ve seen a handful of 2 piece Scat cast replacement and 9000 series cranks that were in dirt track applications. (Broken)

I would have a factory cast crank in that application if budget restricted, if you’re planning multiple seasons I feel a budget forged steel crank is a worthy investment.

[Krooser]

My buddies ran those GM cast cranks in dirt late models for two seasons before switching them out.

[mag2555]

If you get a factory cast crank and take the 2.5 hours of time to grind & polish off all the casting seems and sharp edges and balance it to 1” instead of the common 3” spec it may never fail if the rev’s don’t top 7500 and your making less then 550 hp.