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5.7 stock crank question #1961993 12/02/15 08:43 PM 12/02/15 08:43 PM
Joined: Jan 2004 Posts: 8,233 fredericksburg,va C cudaman1969 OP master
cudaman1969 OP master C Joined: Jan 2004 Posts: 8,233 fredericksburg,va	Ok, I hear the cranks are weak but who has broken a 5.7 crank and how much power or rpm did it take?

Re: 5.7 stock crank question [Re: cudaman1969] #1962047 12/02/15 10:01 PM 12/02/15 10:01 PM
Joined: Feb 2006 Posts: 491 South Dakota kilo1 mopar
kilo1 mopar Joined: Feb 2006 Posts: 491 South Dakota	Not many broken cranks that I have seen , on engines with about 600 HP with no issues. USMC 1982-1988 GM Parts 1988 -2006 US Army 2006-2015

Re: 5.7 stock crank question [Re: cudaman1969] #1962103 12/02/15 11:27 PM 12/02/15 11:27 PM
Joined: Jan 2005 Posts: 3,635 Oakland, MI D dizuster master
dizuster master D Joined: Jan 2005 Posts: 3,635 Oakland, MI	I have two stock core motors, one has a broken crank. But I haven't taken it apart to diagnose. But it's just stock... Not 600hp

Re: 5.7 stock crank question [Re: dizuster] #1962105 12/02/15 11:31 PM 12/02/15 11:31 PM
Joined: Jan 2005 Posts: 12,419 Kalispell Mt. H HotRodDave I Live Here
HotRodDave I Live Here H Joined: Jan 2005 Posts: 12,419 Kalispell Mt.	I have seen a lot of broken rods in 5.7s but never a broken crank. I am not causing global warming, I am just trying to hold off a impending Ice Age!

Re: 5.7 stock crank question [Re: cudaman1969] #1962144 12/03/15 12:16 AM 12/03/15 12:16 AM
Joined: Dec 2013 Posts: 198 Stinnett, Tx R rumblebee4232 member
rumblebee4232 member R Joined: Dec 2013 Posts: 198 Stinnett, Tx	Never seen a broken crank just rods.. one I bought to use as a stroker had a rod journal that was wore down 1/4 inch(below the surface all the way around) that was still running when they pulled it because it was making noise..

Re: 5.7 stock crank question [Re: cudaman1969] #1962305 12/03/15 11:41 AM 12/03/15 11:41 AM
Joined: May 2005 Posts: 723 Houston Tx Uhcoog1 super stock
Uhcoog1 super stock Joined: May 2005 Posts: 723 Houston Tx	Lots of used forged takeout 6.1 cranks out there for cheap ($150). Not worth running the stock 5.7 crank if building the motor IMO -'02 Dodge Viper Ex-World Challenge racecar -'73 Duster, 6.1 based 392 hilborn hemi, tko600, full floater rear 9", Hellwig custom bars, viper brakes, built for road course

Re: 5.7 stock crank question [Re: Uhcoog1] #1962378 12/03/15 02:16 PM 12/03/15 02:16 PM
Joined: Jan 2004 Posts: 8,233 fredericksburg,va C cudaman1969 OP master
cudaman1969 OP master C Joined: Jan 2004 Posts: 8,233 fredericksburg,va	Originally Posted By Uhcoog1 Lots of used forged takeout 6.1 cranks out there for cheap ($150). Not worth running the stock 5.7 crank if building the motor IMO Been looking, I haven't found one that cheap, let me know if you know of one somewhere. Best I found was $450

Re: 5.7 stock crank question [Re: cudaman1969] #1962407 12/03/15 03:04 PM 12/03/15 03:04 PM
Joined: Jan 2005 Posts: 12,419 Kalispell Mt. H HotRodDave I Live Here
HotRodDave I Live Here H Joined: Jan 2005 Posts: 12,419 Kalispell Mt.	I heAr the 6.1 crank drops in but how could the balance be right with bigger bores resulting in bigger pistons and rings? Or is it just close enough it don't make a difference? I am not causing global warming, I am just trying to hold off a impending Ice Age!

Re: 5.7 stock crank question [Re: cudaman1969] #1962672 12/03/15 09:43 PM 12/03/15 09:43 PM
Joined: Feb 2011 Posts: 4,302 Nebraska 72Swinger master
72Swinger master Joined: Feb 2011 Posts: 4,302 Nebraska	I would balance with the 5.7 bore pistons used and whatever rods of choice. Also would use a 6.1,balancer at a bare minimum. Mopar to the bone!!!

Re: 5.7 stock crank question [Re: cudaman1969] #1962675 12/03/15 09:48 PM 12/03/15 09:48 PM
Joined: Feb 2011 Posts: 4,302 Nebraska 72Swinger master
72Swinger master Joined: Feb 2011 Posts: 4,302 Nebraska	Also wanted to add that the 6.1 crank I pulled out of my core engine is NICE. All counterweights fully machined and dressed, no rough flashing anywhere. The Manley I replaced it with only had drilled rod journals as an advantage. Mopar to the bone!!!

Re: 5.7 stock crank question [Re: cudaman1969] #1962852 12/04/15 01:43 AM 12/04/15 01:43 AM
Joined: Apr 2009 Posts: 3,414 Toronto M mshred master
mshred master M Joined: Apr 2009 Posts: 3,414 Toronto	Isn't there the higher rpm oiling issue though with the stock cranks?

Re: 5.7 stock crank question [Re: cudaman1969] #1963307 12/04/15 07:17 PM 12/04/15 07:17 PM
Joined: May 2005 Posts: 723 Houston Tx Uhcoog1 super stock
Uhcoog1 super stock Joined: May 2005 Posts: 723 Houston Tx	Originally Posted By cudaman1969 Originally Posted By Uhcoog1 Lots of used forged takeout 6.1 cranks out there for cheap ($150). Not worth running the stock 5.7 crank if building the motor IMO Been looking, I haven't found one that cheap, let me know if you know of one somewhere. Best I found was $450 Try LXforums. Or I have one out of a spun rod bearing motor, just no box for it ATM. Originally Posted By mshred Isn't there the higher rpm oiling issue though with the stock cranks? They are cross drilled. The drag pak guys turn em to 8200-8500 without issue with a 9 qt pan + 3 qt accusump. You will run a 6 qt swap pan dry around 7500 (ask Joe- he knows first-hand). -'02 Dodge Viper Ex-World Challenge racecar -'73 Duster, 6.1 based 392 hilborn hemi, tko600, full floater rear 9", Hellwig custom bars, viper brakes, built for road course

Re: 5.7 stock crank question [Re: Uhcoog1] #1963420 12/04/15 11:09 PM 12/04/15 11:09 PM
Joined: Nov 2009 Posts: 3,410 Belpre,Ohio C CHAPPER master
CHAPPER master C Joined: Nov 2009 Posts: 3,410 Belpre,Ohio	Originally Posted By Uhcoog1 Originally Posted By cudaman1969 Originally Posted By Uhcoog1 Lots of used forged takeout 6.1 cranks out there for cheap ($150). Not worth running the stock 5.7 crank if building the motor IMO Been looking, I haven't found one that cheap, let me know if you know of one somewhere. Best I found was $450 Try LXforums. Or I have one out of a spun rod bearing motor, just no box for it ATM. Originally Posted By mshred Isn't there the higher rpm oiling issue though with the stock cranks? They are cross drilled. The drag pak guys turn em to 8200-8500 without issue with a 9 qt pan + 3 qt accusump. You will run a 6 qt swap pan dry around 7500 (ask Joe- he knows first-hand). I had a 10qt pan with belt drive Barnes oil system turning about 7200-7300 RPM and the stock crank......#3 rod quit oiling...DEVASTATING results. Molnar crank and no problems at 7800-8000 RPM. This has been hashed out for quite awhile. I, and many others, have concluded that there is a problem with the stock crank oiling. JMO...$.02...etc. Try one yourself and report back later.?? If you like drag racing, support your local track.

Re: 5.7 stock crank question [Re: cudaman1969] #1963437 12/04/15 11:36 PM 12/04/15 11:36 PM
Joined: Jan 2012 Posts: 1,541 USA H hudsonhornet7x pro stock
hudsonhornet7x pro stock H Joined: Jan 2012 Posts: 1,541 USA	Would this be ALL stock cranks, 6.1 and 6.4 included?

Re: 5.7 stock crank question [Re: cudaman1969] #1963441 12/04/15 11:37 PM 12/04/15 11:37 PM
Joined: Feb 2011 Posts: 4,302 Nebraska 72Swinger master
72Swinger master Joined: Feb 2011 Posts: 4,302 Nebraska	I think the 6.1's have better prep than 5.7's. Mopar to the bone!!!

Re: 5.7 stock crank question [Re: CHAPPER] #1963810 12/05/15 03:58 PM 12/05/15 03:58 PM
Joined: Jan 2004 Posts: 8,233 fredericksburg,va C cudaman1969 OP master
cudaman1969 OP master C Joined: Jan 2004 Posts: 8,233 fredericksburg,va	Originally Posted By CHAPPER Originally Posted By Uhcoog1 Originally Posted By cudaman1969 Originally Posted By Uhcoog1 Lots of used forged takeout 6.1 cranks out there for cheap ($150). Not worth running the stock 5.7 crank if building the motor IMO Been looking, I haven't found one that cheap, let me know if you know of one somewhere. Best I found was $450 Try LXforums. Or I have one out of a spun rod bearing motor, just no box for it ATM. Originally Posted By mshred Isn't there the higher rpm oiling issue though with the stock cranks? They are cross drilled. The drag pak guys turn em to 8200-8500 without issue with a 9 qt pan + 3 qt accusump. You will run a 6 qt swap pan dry around 7500 (ask Joe- he knows first-hand). I had a 10qt pan with belt drive Barnes oil system turning about 7200-7300 RPM and the stock crank......#3 rod quit oiling...DEVASTATING results. Molnar crank and no problems at 7800-8000 RPM. This has been hashed out for quite awhile. I, and many others, have concluded that there is a problem with the stock crank oiling. JMO...$.02...etc. Try one yourself and report back later.?? Are the 6.1-6.4 cranks drilled the same as 5.7? Are the steel factory cranks junk too?

Re: 5.7 stock crank question [Re: cudaman1969] #1963869 12/05/15 06:04 PM 12/05/15 06:04 PM
Joined: Jun 2005 Posts: 2,776 Ontario Canada M MattW master
MattW master M Joined: Jun 2005 Posts: 2,776 Ontario Canada	No they 6.1 6.4 and I'm thinking 6.2 are not drill all the way through the mains. I posted picture of 6.1 and 5.7 crank on here.

Re: 5.7 stock crank question [Re: cudaman1969] #1963895 12/05/15 06:49 PM 12/05/15 06:49 PM
Joined: Feb 2011 Posts: 4,302 Nebraska 72Swinger master
72Swinger master Joined: Feb 2011 Posts: 4,302 Nebraska	The 6.1 crank in my above pics was a high mileage, broken valve spring core engine. Only imperfection was #3 main had a light scratch that would easily polish out. You can see it in the pics. It ate something as I think #3 is what feeds the heads IIRC. Last edited by 72Swinger; 12/05/15 06:50 PM. Mopar to the bone!!!

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