Re: Will factory 440 block survive for very long at 800 HP level
[Re: BigHemiVegas]
#2455988
02/23/18 03:53 AM
02/23/18 03:53 AM
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Joined: Jan 2003
Posts: 6,591 Canton, Ohio
Sport440
master
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master
Joined: Jan 2003
Posts: 6,591
Canton, Ohio
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No not very long so wouldn't even consider it. Start with a low deck motor, it will last longer, but it will still fail at that hp in a matter of time. How long, depends on the quality of the build.
Some haven't made it past the dyno, some, a pass or two, others built pretty good , 200/300, after that its just a time bomb, take your chances and expect a failure.
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Re: Will factory 440 block survive for very long at 800 HP level
[Re: Sport440]
#2455993
02/23/18 04:16 AM
02/23/18 04:16 AM
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Joined: Feb 2005
Posts: 20,174 PA.
pittsburghracer
"Little"John
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"Little"John
Joined: Feb 2005
Posts: 20,174
PA.
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I’m not big on throwing out horsepower numbers because I’ve never had on on a dyno but my 440 (500 Stroker) lasted 275 runs going low 8.60’s @ 2500 pounds. No concrete, no gridle and when I took it apart to freshen it was cracked up through the mains. I bought a Keith Black block and a mega block after that.
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
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Re: Will factory 440 block survive for very long at 800 HP level
[Re: pittsburghracer]
#2456021
02/23/18 10:07 AM
02/23/18 10:07 AM
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Joined: Nov 2011
Posts: 287 PA
Harry's Taxi 2
enthusiast
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enthusiast
Joined: Nov 2011
Posts: 287
PA
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Has anyone seen a correlation between block strength and stroke at say 7000 rpm for both?
ex. longer stroke = more prone to cracked main webbing?
'86 Maple Grove KOS Mopar low qualifier......true street legal with no power adders.
NOS-used when losing since 1940.
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Re: Will factory 440 block survive for very long at 800 HP level
[Re: Harry's Taxi 2]
#2456033
02/23/18 10:47 AM
02/23/18 10:47 AM
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Joined: Jan 2003
Posts: 4,448 Phoenix, AZ
MoparBilly
master
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master
Joined: Jan 2003
Posts: 4,448
Phoenix, AZ
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Has anyone seen a correlation between block strength and stroke at say 7000 rpm for both?
ex. longer stroke = more prone to cracked main webbing? Definitely. The 3.75 crank seems to be perfect for the strength of the block. we've ran 650 hp 440s and hit them with big nitrous for years without cracking a single block. As soon as you introduce a big arm, things get dicey. Some of that is because the strokers are more prone to detonation with a narrower tuning window (although the same could be said of dome piston 440s). Another consideration is piston speed, We prefer to keep the rpm down on our stock block strokers.
"Livin' in a powder keg and givin' off sparks"
4 Street cars, 5 Race engines
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Re: Will factory 440 block survive for very long at 800 HP level
[Re: Harry's Taxi 2]
#2456043
02/23/18 11:11 AM
02/23/18 11:11 AM
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Joined: Jan 2003
Posts: 10,000 Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 10,000
Frostbitefalls MN (Rocky&Bullw...
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Has anyone seen a correlation between block strength and stroke at say 7000 rpm for both?
ex. longer stroke = more prone to cracked main webbing? Bob wieght is part of th equation, and often you can reduce rpm if the build is head limited, like small ports on a bigger stroker. But in order to make the stresses equal, the rpm has to drop by the same percent that the stroke increases. If i read the formulas correctly, to any change in either bob wieght, rpm, or stroke will increase the stress by the square of the change. And it is cumulative of the answer. Double the stroke from 3 to 4 inch stress at 3 in would be a facter of 9. Double the rpm, you have to square the first answer, or 9 multiplied by 2 squared, or 9 x 4, equals 36! With that info, a 400 with a 383 crank cut down to 3.54 stroke and bored to 4.375 makes 426 cubes and small port heads makes a lot of sense for a bracket motor.
Last edited by gregsdart; 02/23/18 11:18 AM.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Will factory 440 block survive for very long at 800 HP level
[Re: MoparBilly]
#2456048
02/23/18 11:20 AM
02/23/18 11:20 AM
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Joined: Nov 2011
Posts: 287 PA
Harry's Taxi 2
enthusiast
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enthusiast
Joined: Nov 2011
Posts: 287
PA
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I've observed the block breakage vs stroke thing within my local circle too, but no one seems to mention it when discussing block strength. There also seems to be something in the aftermarket cylinder head chamber shapes (oem copies verses the better burn heart shaped ones) that has an effect on block durability within a certain power/rpm range. Has anyone seen a correlation between block strength and stroke at say 7000 rpm for both?
ex. longer stroke = more prone to cracked main webbing? Definitely. The 3.75 crank seems to be perfect for the strength of the block. we've ran 650 hp 440s and hit them with big nitrous for years without cracking a single block. As soon as you introduce a big arm, things get dicey. Some of that is because the strokers are more prone to detonation with a narrower tuning window (although the same could be said of dome piston 440s). Another consideration is piston speed, We prefer to keep the rpm down on our stock block strokers.
'86 Maple Grove KOS Mopar low qualifier......true street legal with no power adders.
NOS-used when losing since 1940.
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Re: Will factory 440 block survive for very long at 800 HP level
[Re: BigHemiVegas]
#2456049
02/23/18 11:20 AM
02/23/18 11:20 AM
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Joined: Jan 2003
Posts: 10,000 Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 10,000
Frostbitefalls MN (Rocky&Bullw...
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To get this math i posted right, i had to do more than one edit. It is now correct as i understand the math.
Last edited by gregsdart; 02/23/18 11:24 AM.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Will factory 440 block survive for very long at 800 HP level
[Re: gregsdart]
#2456058
02/23/18 12:00 PM
02/23/18 12:00 PM
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Joined: Feb 2005
Posts: 20,174 PA.
pittsburghracer
"Little"John
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"Little"John
Joined: Feb 2005
Posts: 20,174
PA.
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Just remember there is a big difference between saying it worked for X amount of years or X amount of passes. For some guys 275 passes would be a lifetime but for a weekly bracket racer not so much. I had a good friend that would brag about his big block Chevy in his front engine dragster still being together for over 25 years every time he got drunk. He hasn’t raced the car in 24 years. True story.
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
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Re: Will factory 440 block survive for very long at 800 HP level
[Re: pittsburghracer]
#2456061
02/23/18 12:15 PM
02/23/18 12:15 PM
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Joined: Dec 2013
Posts: 4,674 Wichita
GY3
master
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master
Joined: Dec 2013
Posts: 4,674
Wichita
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I took over 7.5 lbs. out when going to the stroker assembly vs. the stock 440 stuff!
'63 Dodge 330 11.19 @ 121 mph Pump gas, n/a, through the mufflers on street tires with 3.54's. 3,600 lbs. 10.01 @ 133mph with a 250 shot of nitrous an a splash of race gas. 1.36 60 ft. 3,700 lbs.
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Re: Will factory 440 block survive for very long at 800 HP level
[Re: BigHemiVegas]
#2456250
02/23/18 05:28 PM
02/23/18 05:28 PM
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Joined: Dec 2005
Posts: 11,570 Fulton County, PA
CMcAllister
Mr. Helpful
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Mr. Helpful
Joined: Dec 2005
Posts: 11,570
Fulton County, PA
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With the heads and parts available today, you can trip and fall and still make 2HP+/CI.
If the results don't match the theory, change the theory.
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Re: Will factory 440 block survive for very long at 800 HP level
[Re: BigHemiVegas]
#2456336
02/23/18 09:25 PM
02/23/18 09:25 PM
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Joined: Oct 2011
Posts: 326 Alberta
Wookie316
enthusiast
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enthusiast
Joined: Oct 2011
Posts: 326
Alberta
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I’m at 840 in a 400 block. We’ll see what happens this season. I watch things as close as I can and keep the tune in check. I’m sure one Day I let go of the button and that will be it. I hope that when the day comes I may actually be able to get my hands on a KB block. Here’s to dreaming.
1971 Plum Crazy Super Bee. 572 World Aluminum block with a Cope 727 & Dana 4.10 out back. 9.88 @ 138 with a 1.35 60 NA. Dialed back to 10.0’s. 4000 lbs with me in it.
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Re: Will factory 440 block survive for very long at 800 HP level
[Re: BigHemiVegas]
#2456367
02/23/18 10:50 PM
02/23/18 10:50 PM
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Joined: Oct 2007
Posts: 4,206 New York
polyspheric
master
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master
Joined: Oct 2007
Posts: 4,206
New York
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I'm sorry, I've wandered into the children's room.
Boffin Emeritus
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Re: Will factory 440 block survive for very long at 800 HP level
[Re: polyspheric]
#2456387
02/23/18 11:32 PM
02/23/18 11:32 PM
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Joined: Feb 2005
Posts: 20,174 PA.
pittsburghracer
"Little"John
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"Little"John
Joined: Feb 2005
Posts: 20,174
PA.
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Blower engines live longer: 1. the big spike in cylinder pressure from nitrous or high CR N/A occurs later in the rotation with boost when the rod angle is safer 2. the inertial load on the rods ATDC (engine vacuum added to reciprocating mass) is replaced with mild pressure. Rough math, using 4.50" piston for added dramatic impact: 1" WOT vacuum = .49 psi is 28,000 grams (all 8 pistons) added to the piston etc. mass tensile load, vs. 20 psi boost = 1,154,000 grams subtracted from mass I'll bet you are a lot of fun at a party. NOT!!!!!!!!!!!!!!!!!
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
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