Speed Demon

iTrader: (14)

I have an LS2 with forged pistons and rods and stock cast crank (3.622 stroke).

What 3.622 stroke forged crankshaft would you suggest to replace the stock cast crank? The bob weight of the current rotating assembly is 1735 grams.
See inspection data attached.

The engine is NA, in 3200lb car used in road race/track day car, with minimal street use.

I am looking at upgrading the crank b/c I have the engine torn down to replace a broken lifter and install bronze lifter bores. Engine has 2500 miles on it.

ATK Engines

iTrader: (1)

Is your crank damaged? The stock crank can handle some power....K1 will get the job done if you need a forged crank.

machinistone

I'm done with K1 - Molnar Tech(former owner of K1) and Callies Compstar are better pieces in that price range.

But as was said, the stock crank is very strong as long as your balance and tune are good.

Speed Demon

iTrader: (14)

Thanks for the input guys.

I haven't heard of Molnar Tech.

The stock crank I have has had the journals turned once and looks like they need turned again due to some oil pump cavitation issues.

I have heard the stock crank is very strong. I've also heard the stock rear diff in my car (E36 M3) and can hold way more power than my engine is making....then it didn't take long for the pinion gear teeth to start peeling off.

A stock crank might hold up for a while and I don't want to find out how short that while is.

LLLosingit

iTrader: (4)

You can't go wrong with a Callies Dragonslayer or Callies Magnum. Callies Compstar would run you around $900 and is a good crankshaft and probably more than capable but more of a budget crankshaft.

ATK Engines

iTrader: (1)

Def wouldn't got .020/.020 on a stock crank for any decent performance build. We do sell a .010/.010 reman crank for a very cheap cost, or we can help you out with a K1 as well if you decide to go that route.

http://www.high-performance-engines....uct-p/cct8.htm

SydwayZ

Callies/lunati would be my 1st pick. After that K-1 (took one of these up to 1062 Whp. Only spun to 6500 though). The stock cranks I have been taken north of 1400 crank. Now will it last long, probably not, but it has been done.

gnx7

iTrader: (28)

Get another stock crank and rebalance.. then mill heads for as much compression as possible on your fuel.

I built a stock LS2 bottom end (new bearings/rings) and LS3 heads/intake that made around 460rwhp for a road race customer (dry sump, road race SCCA unlimited RX-7). He beat the living snot out of it for 2 seasons with no issues. None. You don't need a forged crank at your level. Spend $150 or less on a used one.

If you go forged go stroker.... torque out of the corners is where its at.

99wssixm6

iTrader: (3)

No ones likes Eagle or Scat?? I know they are cheaper but Iv read a lot of good reviews and I plan to go with a Scat for my 402 build.

supermaro

iTrader: (64)

What about forged LSA GM cranks? Anyone using those?

427 zeo6

What about the forged LS3 crank used in the dry sump motors. They are reasonably priced quality is top notch.

64post

iTrader: (5)

8 bolt flywheel means that has to changed.

axe murderer

iTrader: (3)

Pretty sure the LSA is the 8 bolt but the dry sump cranks have a longer snout, I've seen some engine builders on YB say the GM forged cranks aren't that good.
I think there's a standard flange/snout GM LS3 forged crank crank used in some cars.

As for the Chinese cranks Compstar has the best size & finish, they get polished & checked for size in the US & if they're out Callies sells them as blems/2nds.
Unlike most of the builders on here my local machine shop has a crankshaft grinder, if you ever ground an Eagle, K1 etc you'd see how bad they are when you touch them with the wheel.
Talking to guys @ Callies they refer to this as lobing which basically means it has low spots.

machinistone

Yep - I see this all the time and avoid Eagle cranks like the plague. K1 is better, but the Compstar and Molnar cranks cannot be beat at that price point.

Speed Demon

iTrader: (14)

So can anyone confirm that the LS3 forged crank has an 8 bolt flywheel flange?

axe murderer

iTrader: (3)

I doubt it, LSA has an 8 bolt & I think LS9 has a 9 bolt.
LS7 is a dry sump motor so I doubt if a dry sump LS3 has an 8 bolt.
You can use a spacer with a dry sump crank or cut the snout down.

http://www.yellowbullet.com/forum/sh...d.php?t=556575

427 zeo6

Mine is 6 bolt on my 2010 dry sump motor. It does have a 25mm longer snout just like the LS7 if your going wet sump, Scoggin Dickey Chevy has a spacer.

gnx7

iTrader: (28)

you can also cut down the snout and run it as a regular wet sump

Project GatTagO

iTrader: (7)

LSA crank is wet sump and has 8 bolt flange.

Andrew