440 Blocks
#2671174
06/28/19 03:01 PM
06/28/19 03:01 PM
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Joined: Jan 2005
Posts: 1,781 Keymar, MD
DusterKid
OP
top fuel
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OP
top fuel
Joined: Jan 2005
Posts: 1,781
Keymar, MD
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Always hear about 440 blocks cracking. Would like to do a poll to see who has personally have/haven't cracked a block. (Cracked caused by stress, etc, not from a rod breaking and going out the side, etc.)
Last edited by DusterKid; 06/28/19 03:02 PM.
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Re: 440 Blocks
[Re: DusterKid]
#2671192
06/28/19 03:31 PM
06/28/19 03:31 PM
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Joined: Aug 2003
Posts: 4,744 On the parachute mount
n20mstr
master
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master
Joined: Aug 2003
Posts: 4,744
On the parachute mount
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I have an RB that I have used...went 9.0's with nitrous in a 3600lb car. Alum rods, stock stroke and stock main caps I have been told..."keep it from detonating, it might live"....and " if it don't crack right away, it might last.."
Its sitting in my basement now, and I keep telling myself im going to use that shortblock again someday
I voted NO
Last edited by n20mstr; 06/28/19 03:38 PM.
....BAD A$$ STREET CAR.....
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Re: 440 Blocks
[Re: n20mstr]
#2671245
06/28/19 05:43 PM
06/28/19 05:43 PM
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Joined: Feb 2005
Posts: 20,272 PA.
pittsburghracer
"Little"John
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"Little"John
Joined: Feb 2005
Posts: 20,272
PA.
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275 passes running 8.60’s in my Daytona. 440source assembly and their steel caps. When I tore it down for rebuild it was cracked up thru the mains. It never leaked a drop of water.
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.38@138.67
Livin and lovin life one day at a time
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Re: 440 Blocks
[Re: pittsburghracer]
#2671255
06/28/19 06:14 PM
06/28/19 06:14 PM
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Joined: Aug 2003
Posts: 43,719 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,719
Bend,OR USA
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275 passes running 8.60’s in my Daytona. 440source assembly and their steel caps. When I tore it down for rebuild it was cracked up thru the mains. It never leaked a drop of water. I've seen the same thing he has, aluminum rods with a stock stroke OEM forged steel crankshaft cracked between #1 nd #3 cylinders at the bottom of the cylinder walls into the #2 main webbing through it to the bearing surface I had a OEM 426 M.W. block crack the same place but it broke a rod due to spinning the #1 rod bearing and the rod broke and hit the side of the block on the left front
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: 440 Blocks
[Re: Cab_Burge]
#2671280
06/28/19 07:02 PM
06/28/19 07:02 PM
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Joined: Jan 2003
Posts: 14,531 So. Burlington, Vt.
fast68plymouth
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 14,531
So. Burlington, Vt.
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3 customer motors.
2- 440’s and a 493.
575hp, 625hp, 695hp
And easily a dozen or more cracked stock steel 440 cranks after they’ve been in bracket cars for a while........usually multiple cracks. Actually....... more uncommon to have it not be cracked.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
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Re: 440 Blocks
[Re: fast68plymouth]
#2671345
06/28/19 10:33 PM
06/28/19 10:33 PM
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Joined: Feb 2005
Posts: 20,272 PA.
pittsburghracer
"Little"John
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"Little"John
Joined: Feb 2005
Posts: 20,272
PA.
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3 customer motors.
2- 440’s and a 493.
575hp, 625hp, 695hp
And easily a dozen or more cracked stock steel 440 cranks after they’ve been in bracket cars for a while........usually multiple cracks. Actually....... more uncommon to have it not be cracked. But when I was running high 9’s with Stock cranks after 3 years when I did a rebuild I stopped even magnifluxing then. They always showed cracks so I just started over with a fresh crank and threw that one on the scrap pile
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.38@138.67
Livin and lovin life one day at a time
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Re: 440 Blocks
[Re: DusterKid]
#2671441
06/29/19 09:17 AM
06/29/19 09:17 AM
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Joined: Oct 2007
Posts: 4,219 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,219
New York
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I see the pattern of where they can break. My question: IDT future breakage can be accurately predicted by HP alone. Exactly what factors are involved? Actual maximum cylinder pressure at highest point too near TDC (like nitrous) Very low rod ratio (4-1/2" stroke, BBC + .400" rod = 1.45:1) Knock Crank stiffness (worse with stroke increase, BBC rod journal) B size mains (smaller crank, more saddle and cap area) vs. RB (bigger crank, smaller caps)
IIRC generally accepted that supercharged power is easier on the bottom end because the max cylinder pressure is less (than the same power NA) and occurs over a longer rotation period. But how much?
Boffin Emeritus
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Re: 440 Blocks
[Re: DusterKid]
#2671484
06/29/19 10:57 AM
06/29/19 10:57 AM
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Joined: Jun 2004
Posts: 119 SE VA
hemibee69
member
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member
Joined: Jun 2004
Posts: 119
SE VA
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I personally have cracked 2 different stock 440 blocks, couple hundred runs on each i guess. No girdle or block filler. #2 main saddle cracked up into the cyl wall, same place both blocks. Water in the oil the first clue. Did not throw a rod either time. Took it apart as soon as the milky oil showed up. Eagle 4.15" crank, eagle rods, weisco pistons, B1BS heads, Alum main caps both times. 35 deg timing, 9.00 @ 145 2800lbs, 7200 rpm at the stripe.. Put a world block in no more cracks, 8 years later. On a side note I put 600 runs on aa stock block, crank, main caps, no girdle or block fill. But it had aluminum rods, the rods had .25" side clearance from rubbing on the crank sides. You know what the old saying" it is just a matter of time before a stock block fails at higher power levels. John
Last edited by hemibee69; 06/29/19 11:08 AM.
1969 Orig Hemi Super Bee Post 4 spd Red on Red (Sold sadly) 1970 Cuda Drag car 500" B1/BS 8.63 @ 155 mph 1970 Challenger SE 383 4 bbl A/C PB PS Leather 1971 Orig 440+6 Cuda 4 spd Shaker In-Violet
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Re: 440 Blocks
[Re: FastOrange]
#2671621
06/29/19 04:12 PM
06/29/19 04:12 PM
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Joined: Jan 2003
Posts: 1,238 North Central, Indiana
Roughbird72
pro stock
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pro stock
Joined: Jan 2003
Posts: 1,238
North Central, Indiana
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Even using an ARP main stud kit, Upon inspection, my main caps machined mating surfaces, show fretting damage. In other words, the caps are moving. I suspect at high RPM loads in the 675 HP range. Sold off several stock blocks when the World Blocks debuted. Unfortunately, the World blocks ceased production. I doubt you'll find caps that don't walk in anything that's being twisted harder than passenger car use.
72 Plymouth Roadrunner 11.08@123.25
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Re: 440 Blocks
[Re: Roughbird72]
#2671661
06/29/19 06:55 PM
06/29/19 06:55 PM
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Joined: Mar 2006
Posts: 9,973 MI, usa
dvw
master
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master
Joined: Mar 2006
Posts: 9,973
MI, usa
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Unported-1 Indys, stock cross ram, .650 roller, 4.150 Mopar crank, 498, 660hp, never saw 6900rpm. Pulled the front 2 main webs right out of the block. Broke the crank in half right in front of the #3 main. Doug
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