Re: 4.125/ 4.250" stroke stock block SB combos
[Re: mopar dave]
#2402334
11/12/17 02:17 AM
11/12/17 02:17 AM
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Joined: Jan 2003
Posts: 11,786 Portage,michigan
B3422W5
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 11,786
Portage,michigan
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I agree. when I first replaced my 12:1 ported J head 340 with my w2 headed 408 I was very disappointed. Ran the same 4 speed and 4.10 gears although the 408 was 10.5:1. took me another 6-8yrs to get it in the mid tens. That 340 was a very impressive street/strip motor. It would be fun to do a x block with the 3.79 crank roller cam and w9 or victor head. I would think it would last along time buzzing it to 7-7500. We will get to find out real soon what a nice 3.79/ W9 deal will run. By good local buddy Scottb has exactly that combo built and ready to go for next season. I dont want to spoil his news, but suffice to say its a mighty stout piece. Big bore, lots of cam and compression, and attention to detail. CNC W9's by Modern
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight 418 BPE factory replacement headed stroker, 565 lift solid cam, footbrake street/strip car Best so far, 10.32 1/4 1.41 best 60 foot 6.56 at 104.17
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Re: 4.125/ 4.250" stroke stock block SB combos
[Re: mshred]
#2402369
11/12/17 03:31 AM
11/12/17 03:31 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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Street and strip, and I know my heads may be a limiting factor (stock indy 360-2 cnc 230 heads). I have had my engine up for sale to go BB since nitrous is out of hand in price here now, but havent had much interest so I am going to pull and freshen it... I thought about going to bigger stroke, porting the heads and running n/a. Its a stock block but half filled, and it already has a 4" crank.
Would it be worth it to go bigger? Id like to stay pump gas but raise cr from where it is now (10.4:1) Since you already have the 4" stuff, are the pistons reusable? I don't know if it would be worth it, but I love driving mine on the street with the 4.125 assembly. I have 3.89 gears with a 29.5 tire so it's a pretty mild gear, and I can stab it in any gear at any speed and the response is instant. It made 500+ torque from 4200 to 6400 (540 peak), so it's a fantastic pump gas street motor. I love it when guys talk budget then mention a roller cam and heads that take special rocker gear, headers and intake manifolds. My engine has a set of twenty year old Crane Gold 1.5 rockers and a 600 lift solid flat tappet cam with stock port windows and geometry. Pretty boring stuff for an engine that's shoved me to 10.39-128 NA and 9.43-139 on a small plate. I know, the numbers aren't very impressive compared to the race cars around here, but it has over 6000 street miles on it so far, drinking 89 pump swill.
"Livin' in a powder keg and givin' off sparks"
4 Street cars, 5 Race engines
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Re: 4.125/ 4.250" stroke stock block SB combos
[Re: mshred]
#2402390
11/12/17 10:10 AM
11/12/17 10:10 AM
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Joined: Jan 2003
Posts: 10,088 Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 10,088
Frostbitefalls MN (Rocky&Bullw...
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Here's a combo off the top of my head based on what I just did with a 4 inch crank, only this one would cost less, using stock valvetrain parts. Magnum block at 4.030, 4.25 stroke, 6.2 Hbeam sbc rods, 1.350 (?) Co pistons, 12.5 compression with a flat top piston. All this for 434 cubes. Big mutha thumper hydraulic roller, EQ heads with 2.02 intakes, bowl ported , use stock valve train, 850 and an Airgap intake . Should make 540 hp, 560 torque. Shift at 5800, change plugs and oil for seasonal maintenance. That is what I see as a good, stock block 4.25 stroke combo. The stock block should live fine, sure, you can say the piston side loading would be higher, but that is balanced by a lower shift point. I can see a lightened A body going 10.00 all day long and the driver is comfortable,
Last edited by gregsdart; 11/12/17 10:17 AM.
8.582, 160.18 mph best, 2905 lbs 549, indy 572-13, alky
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Re: 4.125/ 4.250" stroke stock block SB combos
[Re: mshred]
#2402409
11/12/17 11:29 AM
11/12/17 11:29 AM
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Joined: Nov 2004
Posts: 3,547 Syracuse,NY
CompWedgeEngines
master
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master
Joined: Nov 2004
Posts: 3,547
Syracuse,NY
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Wondering who is running bigger then a 4" crank in a production block SB and what your combos are performing like? Thinking about maybe going to a larger crank then 4" if it's worth it I'd do the 4.125 and not look back for your combo.
RIP Monte Smith
Your work is a reflection of yourself, autograph it with quality.
WD for Diamond Pistons,Sidewinder cylinder heads, Wiseco, K1 rods and cranks,BAM lifters, Morel lifters, Molnar Technologies, Harland Sharp, Pro Gear, Cometic, King Engine Bearings and many others.
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Re: 4.125/ 4.250" stroke stock block SB combos
[Re: MoparBilly]
#2402742
11/12/17 09:59 PM
11/12/17 09:59 PM
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Joined: Apr 2009
Posts: 3,433 Toronto
mshred
OP
master
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OP
master
Joined: Apr 2009
Posts: 3,433
Toronto
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Street and strip, and I know my heads may be a limiting factor (stock indy 360-2 cnc 230 heads). I have had my engine up for sale to go BB since nitrous is out of hand in price here now, but havent had much interest so I am going to pull and freshen it... I thought about going to bigger stroke, porting the heads and running n/a. Its a stock block but half filled, and it already has a 4" crank.
Would it be worth it to go bigger? Id like to stay pump gas but raise cr from where it is now (10.4:1) Since you already have the 4" stuff, are the pistons reusable? I don't know if it would be worth it, but I love driving mine on the street with the 4.125 assembly. I have 3.89 gears with a 29.5 tire so it's a pretty mild gear, and I can stab it in any gear at any speed and the response is instant. It made 500+ torque from 4200 to 6400 (540 peak), so it's a fantastic pump gas street motor. I love it when guys talk budget then mention a roller cam and heads that take special rocker gear, headers and intake manifolds. My engine has a set of twenty year old Crane Gold 1.5 rockers and a 600 lift solid flat tappet cam with stock port windows and geometry. Pretty boring stuff for an engine that's shoved me to 10.39-128 NA and 9.43-139 on a small plate. I know, the numbers aren't very impressive compared to the race cars around here, but it has over 6000 street miles on it so far, drinking 89 pump swill. The whole bottom end is reusable I am just toying with going bigger since it will be apart for freshening....sorry my top end isn't budget enough for ya, not my fault I got it for quite a good deal. Your combo sounds impressive, but I would be curious to know what your car weighs too 👍
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Re: 4.125/ 4.250" stroke stock block SB combos
[Re: mshred]
#2402781
11/12/17 11:12 PM
11/12/17 11:12 PM
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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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mshred, I think the 360-2s are perfect for your budget since you already have them! My heads are 220cc intake runner, and even with the mild flat tappet cam it made peak HP at 6600, so I think your heads could handle more stroke and still be effective.
My car is a real deal street car with big radiator, alternator, two seats, two batteries, 8.50 cert cage, all factory glass and bumpers, 15 gallon cell, then you add in a 300+ driver and it's certainly no lightweight! OK, ok it's 3150 with me and the nitrous bottle on board, those Chrysler engineers really outdid themselves in 1962...
mopar dave,
This is not a personal attack against you, as my own brothers think similarly, I'm just trying to advance the conversation. I'm not trying to invalidate anyone's opinion, just asking that you spell it out in hard numbers.
The typical 4" stroker kits with stock style rods run around 1700$ to 2000$. The 4.125 and 4.25 high quality kits from Bloomer and Molnar are about 500$ more.
W-9's, in another thread it was discussed are 6K by the time they are ready to make serious power.
Any head that requires offset rockers just added another 500 to 1000 over the budget of a standard head.
Then we have to have the conversation about the cost difference between a roller cam and all the associated parts versus a flat tappet. Is it really wise to have a .700 lift roller, with a short valve and a 1.88 installed height?
I've also never understood the love affair with big bores. Granted, I know they make a little more power, but in the conversation of small block mopars, we are dealing with a finite amount of available blocks. My X block was standard bore 4.04 after 15 years of racing, when I ordered the 4.125 stroker kit, I only punched it to 4.070. Why go right to max bore immediately?
For guys more versed in big blocks, remember when 4.15 was the go to stroker kit? Then the 4.25 stuff with the 2.20 journal came out and it was lighter and easier to assemble. Same way with the 4.125 stuff with 2.00 journal over the 4.00 kit.
"Livin' in a powder keg and givin' off sparks"
4 Street cars, 5 Race engines
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Re: 4.125/ 4.250" stroke stock block SB combos
[Re: mshred]
#2402792
11/12/17 11:30 PM
11/12/17 11:30 PM
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Joined: Sep 2004
Posts: 2,094 oberlin, Ohio
Rapid340
top fuel
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top fuel
Joined: Sep 2004
Posts: 2,094
oberlin, Ohio
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I like the 4.00 inch stroke SB combo. At 4.125 and 4.250 you start to run into things. Oil pump, windage tray, etc. start to get in the way so the assembly just takes longer and you have to be willing to modify parts and/or buy different parts until you find a combo that works. Using the smaller Chevy rod journals sure helps. For a race engine it might be worth going with the Honda journals or something like that. I think the Hughes Engine kit uses a 4cyl rod bearing to get the size down. I have offset ground 4 in cranks to 4.23 (using honda journal rods) and used SBC large journal rods with callies 4.25 dragon slayer cranks (no longer available) and have never had to do any real significant mods that I wasnt already doing for most 4.000 in. builds. I do tend to use lighter rods than many of the beefiest H-beam rods that are on the market. Windage trays vary but I have used simple spacers and also trimmed some of the tray.
1971 Factory Appearing Duster 340 11.000 @ 122 mph
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Re: 4.125/ 4.250" stroke stock block SB combos
[Re: AndyF]
#2402816
11/12/17 11:57 PM
11/12/17 11:57 PM
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Joined: Oct 2003
Posts: 11,702 W. Kentucky
justinp61
I Live Here
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I Live Here
Joined: Oct 2003
Posts: 11,702
W. Kentucky
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I like the 4.00 inch stroke SB combo. At 4.125 and 4.250 you start to run into things. Oil pump, windage tray, etc. start to get in the way so the assembly just takes longer and you have to be willing to modify parts and/or buy different parts until you find a combo that works. Using the smaller Chevy rod journals sure helps. For a race engine it might be worth going with the Honda journals or something like that. I think the Hughes Engine kit uses a 4cyl rod bearing to get the size down. I'm running a 4.125" crank with a 2.00" rod journal and didn't have any Clarence issues.
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Re: 4.125/ 4.250" stroke stock block SB combos
[Re: 420duster]
#2402941
11/13/17 11:55 AM
11/13/17 11:55 AM
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Joined: Oct 2003
Posts: 11,702 W. Kentucky
justinp61
I Live Here
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I Live Here
Joined: Oct 2003
Posts: 11,702
W. Kentucky
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What kind of rpm’s is suggested with these big arms ? Mine peaked at 6750 on the dyno and at the track I usually shift around 7000.
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Re: 4.125/ 4.250" stroke stock block SB combos
[Re: justinp61]
#2403164
11/13/17 07:07 PM
11/13/17 07:07 PM
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Joined: Jan 2003
Posts: 9,924 Weddington, N.C.
Streetwize
master
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master
Joined: Jan 2003
Posts: 9,924
Weddington, N.C.
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If I remember right the 3.79" stroke was purposely derived to allow a 6.123" rod combo to fit relatively easily within the "new" (at the time) Race blocks shorter 9.2" deck. The 3.79 gives you a 1.18" compression distance with a standard 6.123" rod.
But I think it also can give you pretty close to a near zero deck height when replacing a 3.58" stroke in a 360 while using an off the shelf low compression Smog piston....pretty clever.
This was similar to the reason the 4.15" was settled-on for the big block stroker crank, with only an .022" overbore it allowed you to use an off the shelf 400 piston in a 440 and make a 493.
Last edited by Streetwize; 11/13/17 07:08 PM.
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Re: 4.125/ 4.250" stroke stock block SB combos
[Re: mshred]
#2403212
11/13/17 08:42 PM
11/13/17 08:42 PM
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Joined: Oct 2011
Posts: 559 Idaho
LaRoy Engines
mopar
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mopar
Joined: Oct 2011
Posts: 559
Idaho
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We've got a 1977 360 block running on the street with the Bloomer 4.125 kit. I like it.
Running a Super Victor single plane, 950 cfm 4150 and using some modified Indy LAX heads and running on 91 octane pump gas it makes 474 LB-FT @ 3,000 rpm, 574 LB-FT @ 5,100 rpm and 629 HP @ 6,400 rpm.
The owner is a little wild and the first time it left the shop it had an ignition box with no rev-limiter. It came back in 6 hours with bent exhaust valves. As it is making over 600 HP @ 5,800 rpm, we installed a MSD 6AL-2 and I set the rev-limiter @ 6,100 (619 HP). So now, damn it, he uses the rev-limiter as a shift light.....you know.....winds it until it hits the limiter and then shifts. If I set the limiter at 7,000 rpm he'd still do the same thing. It's just one of the many small reasons I've decided to not build anymore engines after I finish the ones already here.
Last edited by LaRoy Engines; 11/13/17 08:43 PM.
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