Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons
[Re: mopar dave]
#1544595
12/07/13 12:40 PM
12/07/13 12:40 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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Romeo MI
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Dave... my W-9 heads are about 275 cc runners so I have to turn up the revs to make them efficient but I like the revs... depending on the bore I think I would go with more stroke to make the torque and then you could cut down on the revs... JMO
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Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons
[Re: mopar dave]
#1544598
12/07/13 12:48 PM
12/07/13 12:48 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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Quote:
mike, that's entered mi mind also. another thought was maybe my heads cannot keep up with my 4" stroke because of the faster piston speed and the 3.79 would slow it down and get a better cylinder fill.
Thats what I dont know... what runner can handle what piston speed... being that mine are a fair bit bigger and I have the short stroke my peak torque is at 6200 rpm
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Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons
[Re: Dunnuck Racing]
#1544600
12/07/13 01:09 PM
12/07/13 01:09 PM
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Joined: Jan 2007
Posts: 8,042 Mt Morris Michigan
mopar dave
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wow those look good with that stroke. just seems like a 3.79 and with a 1 688 r/s ratio would eliminate friction and binding to possibly make more power with a small head than a 408 and make the stock block last longer. the factorys use the 3 3/4 stroke in a lot of different engines for a reason and there's a lot of fast motors out there using that stroke. almost like a magic stroke, that's why i'v been stuck on that stroke, but i'm open to all opinions or info here. currently my peak hp is at 6600rpm using a 260/269@50 .700 lift roller.
Last edited by mopar dave; 12/07/13 01:11 PM.
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Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons
[Re: Darryls-Demon]
#1544603
12/07/13 05:19 PM
12/07/13 05:19 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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Quote:
This is an interesting thread. I am kind of in the same boat I have an X-block and a pair of 59 degree W9 heads. Thinking of going with a 4.125 stroke and hoping the block will go 4.100, but my car is a street-strip deal and I like to run 3.73s in the car.
Put a gear in it with OD.. best of both worlds
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Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons
[Re: MR_P_BODY]
#1544604
12/07/13 05:51 PM
12/07/13 05:51 PM
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Joined: Jan 2008
Posts: 795 Glendale Az
Darryls-Demon
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Glendale Az
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Quote:
Quote:
This is an interesting thread. I am kind of in the same boat I have an X-block and a pair of 59 degree W9 heads. Thinking of going with a 4.125 stroke and hoping the block will go 4.100, but my car is a street-strip deal and I like to run 3.73s in the car.
Put a gear in it with OD.. best of both worlds
I have looked into doing a OD unit. Looks like one would cost around 3000 dollars and add weight to my already too heavy car.
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Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons
[Re: Darryls-Demon]
#1544605
12/07/13 05:57 PM
12/07/13 05:57 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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Quote:
Quote:
Quote:
This is an interesting thread. I am kind of in the same boat I have an X-block and a pair of 59 degree W9 heads. Thinking of going with a 4.125 stroke and hoping the block will go 4.100, but my car is a street-strip deal and I like to run 3.73s in the car.
Put a gear in it with OD.. best of both worlds
I have looked into doing a OD unit. Looks like one would cost around 3000 dollars and add weight to my already too heavy car.
I went with the 518 which is MUCH less but does add weight... the GV is lighter with a 727 than the 518 but it is $3000 plus the drive shaft... I'm sure you can find a few places to loose the weight
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Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons
[Re: 1967dartgt]
#1544607
12/07/13 06:17 PM
12/07/13 06:17 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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Quote:
How long is the GV unit? Would you get in to driveshaft angle problems on a A body .
Its only like 6" long and the angle hasnt been a issue... plenty of the DW guys run the GV... my 518 is probably a bit longer than the 727 and GV... but when I set up the engine and trans in the Rampage I set it so it was pointed straight at the pinion then rolled in the pinion angle
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Re: another 3.79 vs 4.00 vs 4.125 sb stroke comparisons
[Re: mopar dave]
#1544609
12/07/13 08:54 PM
12/07/13 08:54 PM
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Joined: Jan 2003
Posts: 11,718 Portage,michigan
B3422W5
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I Live Here
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Personally, with the heads you have, or W5 heads like I ran, I think the 4 inch crank is plenty, and well suited to both making power, torque, and longetivity, and reliability. Bigger the bore the better. I also like the longer rod, ran a 6.300 rod. At 4.100 bore the CP domes were only a hair over 400 grams. Bumping your compression up like you are talking about with a 4 inch stroke and correct matching components will make more than plenty of torque to make your car 60 foot plenty good. I know it can be done. I would strongly suggest a better block than you are using so you can reliably run a bigger bore, sticking with your current stroke,and calling Dwayne Porter and having him spec you out the proper roller cam once you get a good shortblock put together.
Last edited by B3422W5; 12/07/13 08:56 PM.
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight 418 BPE factory replacement headed stroker, 565 lift solid cam Best so far, 10.40 @127 1/4 1.41 best 60 foot 6.60 at 103.90 1/8
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