Internal or external balance?
Thread Starter
Racer
Joined: Oct 2006
Posts: 269
Likes: 7
Internal or external balance?
I have a 400 block ready for the rotating assembly. I have decided to stay with a stock 3.75 crank, 6.0" I beam rods and forged pistons. I am undecided on whether or not I should spend he extra money to buy an internaly balanced crankshaft. The difference is about $300. The car will be totally street driven, will never go to the track, will not be over 500 hp or over 6500 rpm. Based on how the car will be used is there any need for internal balance?
Thread Starter
Racer
Joined: Oct 2006
Posts: 269
Likes: 7
The internal crank is 4340 forged steel. Only Scat makes a cast steel crank that can be internally balanced. The cost of internally balanced cast steel Scat crank is only $75 more. But there is a catch. I was told that the Scat 9000 cast steel crank will require significant Mallory to balance. Since Mallory is so expensive the Scat crank will cost more than the difference in price to buy a forged Eagle crank.
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
I called scat about a yr ago asking about the internal balance cast 3.75 crank with 6.00 rod for the next door niegbor who was
considering going bigger for his pickup, they gave me a part #
for a complete rotating kit but I was just going too use lighter
hyper pistons, they told me Competition products would give me a
better pire on the kit then they could. Nieghbor changed mind left
engine as is.
considering going bigger for his pickup, they gave me a part #
for a complete rotating kit but I was just going too use lighter
hyper pistons, they told me Competition products would give me a
better pire on the kit then they could. Nieghbor changed mind left
engine as is.
Last edited by Little Mouse; May 9, 2007 at 10:52 PM.
Drifting
Joined: Apr 2002
Posts: 1,716
Likes: 4
From: New Baden Illinois
The internal crank is 4340 forged steel. Only Scat makes a cast steel crank that can be internally balanced. The cost of internally balanced cast steel Scat crank is only $75 more. But there is a catch. I was told that the Scat 9000 cast steel crank will require significant Mallory to balance. Since Mallory is so expensive the Scat crank will cost more than the difference in price to buy a forged Eagle crank.
