Generation IV Internal Engine 2005-2014 LS2 | LS3 | LS7 | L92 | LS9

3.622 Forged Crank recommendation

Thread Tools
 
Search this Thread
 
Old 12-21-2015 | 11:59 AM
  #1  
Speed Demon's Avatar
Thread Starter
TECH Enthusiast
iTrader: (14)
 
Joined: Nov 2001
Posts: 519
Likes: 0
From: Raleigh, NC
Default 3.622 Forged Crank recommendation

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.
Attached Thumbnails 3.622 Forged Crank recommendation-ls2-short-block-inspection-data-2011.jpg  
Old 12-21-2015 | 03:14 PM
  #2  
ATK Engines's Avatar
FormerVendor
iTrader: (1)
 
Joined: Nov 2013
Posts: 369
Likes: 24
Default

Is your crank damaged? The stock crank can handle some power....K1 will get the job done if you need a forged crank.
Old 12-21-2015 | 10:15 PM
  #3  
machinistone's Avatar
Banned
 
Joined: Aug 2006
Posts: 326
Likes: 0
From: North Bay, CA
Default

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.
Old 12-22-2015 | 07:27 AM
  #4  
Speed Demon's Avatar
Thread Starter
TECH Enthusiast
iTrader: (14)
 
Joined: Nov 2001
Posts: 519
Likes: 0
From: Raleigh, NC
Default

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.
Old 12-22-2015 | 07:35 AM
  #5  
LLLosingit's Avatar
TECH Junkie
10 Year Member
iTrader: (4)
 
Joined: Aug 2013
Posts: 3,837
Likes: 475
From: Iowa
Default

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.
Old 12-22-2015 | 08:19 AM
  #6  
ATK Engines's Avatar
FormerVendor
iTrader: (1)
 
Joined: Nov 2013
Posts: 369
Likes: 24
Default

Originally Posted by Speed Demon
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.
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
Old 12-22-2015 | 08:49 PM
  #7  
SydwayZ's Avatar
Staging Lane
 
Joined: Apr 2015
Posts: 79
Likes: 0
From: New Orleans
Default

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.
Old 12-23-2015 | 02:27 AM
  #8  
gnx7's Avatar
TECH Junkie
20 Year Member
iTrader: (28)
 
Joined: Nov 2002
Posts: 3,522
Likes: 192
From: San Francisco, CA
Default

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.
Old 12-24-2015 | 11:48 AM
  #9  
99wssixm6's Avatar
TECH Apprentice

iTrader: (3)
 
Joined: Nov 2005
Posts: 324
Likes: 1
From: Winter Park FL.
Default

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.
Old 12-24-2015 | 11:59 AM
  #10  
supermaro's Avatar
TECH Apprentice
iTrader: (64)
 
Joined: Mar 2004
Posts: 306
Likes: 1
From: Long Beach, CA
Default

What about forged LSA GM cranks? Anyone using those?
Old 01-01-2016 | 09:31 PM
  #11  
427 zeo6's Avatar
On The Tree
 
Joined: Mar 2012
Posts: 131
Likes: 2
Default

What about the forged LS3 crank used in the dry sump motors. They are reasonably priced quality is top notch.
Old 01-01-2016 | 10:38 PM
  #12  
64post's Avatar
TECH Fanatic
iTrader: (5)
 
Joined: Nov 2011
Posts: 1,694
Likes: 227
From: Sonoma Co. Ca.
Default

Originally Posted by 427 zeo6
What about the forged LS3 crank used in the dry sump motors. They are reasonably priced quality is top notch.
8 bolt flywheel means that has to changed.
Old 01-02-2016 | 11:44 AM
  #13  
axe murderer's Avatar
On The Tree
iTrader: (3)
 
Joined: Jan 2012
Posts: 110
Likes: 0
Default

Originally Posted by 64post
8 bolt flywheel means that has to changed.
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.
Old 01-02-2016 | 01:25 PM
  #14  
machinistone's Avatar
Banned
 
Joined: Aug 2006
Posts: 326
Likes: 0
From: North Bay, CA
Default

Originally Posted by axe murderer

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.
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.
Old 01-02-2016 | 08:36 PM
  #15  
Speed Demon's Avatar
Thread Starter
TECH Enthusiast
iTrader: (14)
 
Joined: Nov 2001
Posts: 519
Likes: 0
From: Raleigh, NC
Default

Originally Posted by 64post
8 bolt flywheel means that has to changed.
So can anyone confirm that the LS3 forged crank has an 8 bolt flywheel flange?
Old 01-03-2016 | 01:59 PM
  #16  
axe murderer's Avatar
On The Tree
iTrader: (3)
 
Joined: Jan 2012
Posts: 110
Likes: 0
Default

Originally Posted by Speed Demon
So can anyone confirm that the LS3 forged crank has an 8 bolt flywheel flange?
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
Old 01-03-2016 | 06:00 PM
  #17  
427 zeo6's Avatar
On The Tree
 
Joined: Mar 2012
Posts: 131
Likes: 2
Default

Originally Posted by Speed Demon
So can anyone confirm that the LS3 forged crank has an 8 bolt flywheel flange?
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.
Old 01-03-2016 | 06:33 PM
  #18  
gnx7's Avatar
TECH Junkie
20 Year Member
iTrader: (28)
 
Joined: Nov 2002
Posts: 3,522
Likes: 192
From: San Francisco, CA
Default

you can also cut down the snout and run it as a regular wet sump
Old 01-03-2016 | 10:28 PM
  #19  
Project GatTagO's Avatar
TECH Senior Member
20 Year Member
iTrader: (7)
 
Joined: Mar 2003
Posts: 10,244
Likes: 1,533
From: The City of Fountains
Default

LSA crank is wet sump and has 8 bolt flange.

Andrew



Quick Reply: 3.622 Forged Crank recommendation



All times are GMT -5. The time now is 11:02 PM.