GS977

i have a 454 i'm putting in my 82. i've had it for years. it's a 454 .030 over. forged ls6 crank, forged lunati pro mod rods, forged pistons, merlin square port heads (2.30 in 1.88 ex valves) dart high rise single plane, 1050 dominator carb.
but i found this scat 4.25 stroke crank that looks really good for $279.00 = 496 ci.
http://www.flatlanderracing.com/scatcranksbbc.html
question is do i really need a forged crank for the street. the cam i was running in thei motor was @ 270 -280 @.050 dur. and i was shifting at @7200rpm. im going to change the cam to move the power range down to @ 6500 rpm. i haven't picked it out yet. i have a 3000 stall converter.
is this scat cast crank worth it. how will it hold up. is it worth giving up my forged 4.00 in crank for the extra .25 stroke cast crank.
it seems that 496 would really be a torque monster!!!!
very tempting.

fugawi

forged don't wast your money on a cast one with a 496.

Indiancreek

Just my opinion, but you have some good stuff going into it. They are only as good as the weakest link. Having said that, there have been some real strong engines made with a cast crank. Sometimes I wonder why people are selling stuff. Last month a guy brought in a stroker BBC crank he had bought used as is. Before I could really look at it, I had it in the direct sun light. On number 3 main in the radius after the sunlight heated it up there must have been 20 tiny cracks. Maybe the seller didn't know it, or maybe he did.

Ben Lurkin

If you're going to 7000 rpm, you need the forged crank. The scat crank you refer to is a good piece, but you're near the limits of what it was designed for.

Nobody.

Just remember, if you change the stroke of the crank, the rod length must change and the piston pin height as well. To go from what you have to a 496, you'll need a complete rotating assembly and have it balanced it as well. You're looking around $2k +/-. If this is just a street car or even a street/strip deal, I'd keep what you have and calm the cam down to the 250ish @ .050" range and enjoy it. Probably going to need to spend that money upgrading the rearend anyway. Lol.

RobbSalzmann

I think you may have a bit too much carb too.

If you cut corners on part quality now, you won't enjoy the car because every time you put your foot in it you'll worry about that $275 crank letting go.

If you want to go fast and cut corners, buy steel rims and run it without carpet.

L88Plus

^ I'm with these guys. Freshen and tweak the 454.

GS977

yea you guys are right. i'll keep my 4.00 steel crank.
thanks

TheSkunkWorks

Good call.

FWIW, the LS6 crank was originally tuftrided, so anything beyond a slight micro-polish will likely remove the hardened surface, requiring retreatment. If it were me, I wouldn't let a shop touch one who doesn't know that, or who couldn't/wouldn't perfrom or outsource that service. IMHO it's just too nice of a crank to degrade it into a standard forged piece.

TSW

MotorHead

The scat crank is a good piece but once you start talking anything near or above 6,000 RPM forggeddaboudit

GS977

i haven't decided on a cam but have @ 3 or 4 i'm looking at. all have around the same rpm range 2500-3000 rpm to 6500-6800 rpm.
i think my dart single plane and 1050 dominator might not be the best choice. i have a pretty new barry grant 4150 style dp. i think it's either a 750 or 850. don't remember. and i think a performer rpm air gap might work better in the rpm range of these cams.

DRIVESHAFT

I can promise you that the Dart intake wont fit under your hood, assuming thats your car in your avatar.
With a standard L88 hood, the best performance intakes that are currently made and will fit are the Performer RPM, the Weiand Stealth, and the Holley Strip Dominator.

GS977

i'm going to list my dart intake and 1050 dom for sale i guess. will the rpm air gap fit under the reg l-88 or do i need to go with the reg perf. rpm.
driveshaft, don't you have a bb in you vette?

TheSkunkWorks

Yes, the RPM AirGap will fit under a standard L88 hood and CAI, as will the Holley Strip Dominator. Choosing the right cfm carb depends on the complete engine combo, not just what some CID based formula may spit out. I've once run a 1050 progressive Dom with Edelbrock C454 monster 2-plane intake on a moderate street 427, and was very pleased with both driveability and performance (MPG aside). Planning on a ~1000 cfm Pro Systems carb for the rect port, solid roller 427 going back in my shark this time around as well, tho still torn between the RPM AirGap and Strip Dom. Honestly, I wouldn't go smaller than an 850 on even a mildly healthy BB. My $.02

TSW

cv67

7200 rpm BBC sounds like fun, go for it.
Forged bottom end for sure on this one, good sized intake.

DRIVESHAFT

The Performer RPM & Performer RPM air gap for a big block are the same height.

Yes, I do have a big block in my car. It makes me very happy.