Sb stroker planning... performance gain?
#1137328
12/16/11 09:07 PM
12/16/11 09:07 PM
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Joined: Nov 2004
Posts: 1,745 Maryland
340_Dart
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OP
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Maryland
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So i'm planning on building a new bottom end for my small block stroker in the future and wondered just how much better it will run... The heads and cam specs will likely not change. Just wondering what an updated bottom end will yield. Current motor:
408 bottom end (4.030 x 4" crank) '75 360 block K1 crank and rods Diamond flat top pistons with 1/16",1/16", 3/16" ring pack Final compression ratio comes out to 10.3 to 1 Indy 360-2 heads and intake converted to dominator flange by W5Dart66 flow specs on heads intake side: 0.0500 52.7 0.1000 81.8 0.1500 111.8 0.2000 143.27 0.2500 174.1 0.3000 203.3 0.3500 231.9 0.4000 257.2 0.4500 280.5 0.5000 298.02 0.5500 309.56 0.6000 319.7 0.6500 324.47 0.7000 331.71 0.7500 332.89
Cam is a solid roller by Predator cams INTAKE .436" lift 264* @ .050" 297* @ .020"108LS EXHAUST.436" lift 268* @ .050" 302* @ .020"108LS
Cam is .698 gross lift with my 1.6 rockers
Current best is 10.04 @ 131.78 in my 3000lb valiant
Now, i'm planning on building a 427 bottom end using: 4.060" bore x 4.125 crank R1A block (340 main, 48* block) 4.125" BPE crank with 2" rod journals Flat top piston with .043,.043, 3mm ring pack Callies compstar rods, 6.200" Final compression ratio at 11 to 1
Now i know these engines are not drastically different, but there are a bunch of small differences, and i wonder how they'll stack up.
What do you all think the difference in et/mph will be?
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Re: Sb stroker planning... performance gain?
[Re: 340_Dart]
#1137329
12/16/11 09:11 PM
12/16/11 09:11 PM
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Joined: Oct 2007
Posts: 3,978 Hilltown Pa
1967dartgt
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master
Joined: Oct 2007
Posts: 3,978
Hilltown Pa
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I would think 2 tenths better.
Brett Miller W9 cnc'd heads STR Chassis fabraction
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Re: Sb stroker planning... performance gain?
[Re: WHITEDART]
#1137331
12/16/11 09:35 PM
12/16/11 09:35 PM
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Joined: Nov 2004
Posts: 1,745 Maryland
340_Dart
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OP
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Maryland
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Quote:
im thinken the same because the extra weigth of the block
You've got a point there, but it should also be more stable are RPM, as this is a 4-bolt main block compared to the factory. And, the cylinder bores should be more stable.
I'd like to see 700 hp out of this motor, but not sure if it can be done on pump gas... Maybe i should just build it as a 13.5-14 to 1 motor and look into E85.
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Re: Sb stroker planning... performance gain?
[Re: 340_Dart]
#1137336
12/17/11 01:17 AM
12/17/11 01:17 AM
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Joined: Oct 2010
Posts: 2,407 Ambridge, Pa.
rickraw
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u will have at least 700hp. should run around 9.70's- mid 80's. should be able to run pump gas w/11-1. i do. street strip 440 sb, 11-1, 9.61@137.91. seeya.
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Re: Sb stroker planning... performance gain?
[Re: 340_Dart]
#1137339
12/17/11 02:11 AM
12/17/11 02:11 AM
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Joined: Sep 2003
Posts: 6,847 Missouri
StrokerPost
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master
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Missouri
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This was my experience with just such a swap. I was running a .030 360, solid flat tappet cam, ported iron heads, about 12.7:1 CR, M1 single plane, 750 Holley DP and 1 7/8" headers. This was in an all steel Dart. It ran consistant 11.20's with a 1 time best of 10.98 @ 122. I built a new short blk (360) .060 for with a Mopar 4" crank for 414 CI. I put in a slightly bigger flat tappet cam, lowered the CR to 12:1, and used the same heads, intake, carb and headers as was on the old motor with the only change being more jet in the 750 and a fresh valve job and springs on the heads. This produced consistant 10.60's with a best of 10.45 @ 127. Nothing in the drivetrain was changed, just more CI. Figuring roughly 1.5-1.7 horse per cube for a bracket style solid flat tappet motor should have given me around 80 additional HP just with the addition of 48 CI. These numbers all line up pretty well with the lower ET I got. Later a bigger carb gave me 1/8 mile times that would have been around 10.36 in the 1/4. I would also guess your gain to be about 2 tenths.
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Re: Sb stroker planning... performance gain?
[Re: rickraw]
#1137341
12/17/11 09:22 AM
12/17/11 09:22 AM
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Joined: Jan 2003
Posts: 32,394
Quicktree
I Win
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I Win
Joined: Jan 2003
Posts: 32,394
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Quote:
u will have at least 700hp. should run around 9.70's- mid 80's. should be able to run pump gas w/11-1. i do. street strip 440 sb, 11-1, [Email]9.61@137.91.[/Email] seeya.
I would think a real 700hp would put a 2900# car in the low 9s not 9.80s
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Re: Sb stroker planning... performance gain?
[Re: fishy340]
#1137344
12/17/11 11:14 AM
12/17/11 11:14 AM
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Joined: Feb 2008
Posts: 181 Long Island, New York
W7 Duster
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member
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Long Island, New York
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Quote:
well i can say this the best workin car! w7duster aka chuck w a 700+hp went sb 9.20's(but that car works perfect) best of everything including headers from kooks that on the dyno were better then the dyno headers,also his 60ft's are mid 20's...so in a perfect car 3000lbs
Don't forget about the killer 904 B1Johnny built for me! 740hp, 575tq on Ryanj's dyno,417cid.
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Re: Sb stroker planning... performance gain?
[Re: fishy340]
#1137346
12/17/11 12:33 PM
12/17/11 12:33 PM
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Joined: Jan 2003
Posts: 11,711 Portage,michigan
B3422W5
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 11,711
Portage,michigan
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I agree about the 2 tenths figure. Its nowhere near 700 horsepower at 11 to 1 with that small cam. my old 422 with similar w5 heads at better than 13.3 compression, with about 10 degrees bigger cam went 9.85 at 3350 pounds. I figured it for about an honest 660 horse. So if you pickup 2 tenths and get your car in the 80's its still 3 or 4 hundred pounds lighter, so nowhere near 700 horse, probably more like an honest 620ish or so. Which is respectable with that cam and compression. Like quicktree said, at 700 horse, your weight of car should go probably 9.20's or 30's, IMO. If it was me, i dont know that i would go through all that stuff for a couple of tenths and have to deal with all the licensing and safety isues running 9's entail. I would just up the compression to 13 to 1 , install a suitable camshaft at that point( probably something 274/282 ish), and get way deeper in the 9's for all your trouble. At THAT point, you would approach 700 ponies.
Last edited by B3422W5; 12/17/11 12:39 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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