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Stock appearing 425hp 383 possible?
#1319622
10/13/12 11:48 AM
10/13/12 11:48 AM
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Joined: Apr 2004
Posts: 364
Houston, Texas
Slant6pak
OP
enthusiast
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OP
enthusiast
Joined: Apr 2004
Posts: 364
Houston, Texas
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Is it possible?
I'm planing on building a 383 for my 1971 Road Runner clone. I'm completely aware I could build a 440 for the same price and make more power... but I've always had a soft spot for 383s.
I'm starting fresh.... I don't even have a core engine yet. I only have 4 restrictions:
I don't want to stoke it.
An Air Grabber must fit, so I'm limited to a DP4B intake (which I already have)
Must run stock HP manifolds.
Valvetrain must fit under stock valvecovers.
Other than that I'm open to all suggestions.
Thanks in advance.
2016 Challenger Scat Pack Shaker  1000 ci Brass Era Speedster project
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Re: Stock appearing 425hp 383 possible?
[Re: Slant6pak]
#1319624
10/13/12 11:56 AM
10/13/12 11:56 AM
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Joined: Jan 2003
Posts: 4,296
Chicago, IL
TonyS451
master
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master
Joined: Jan 2003
Posts: 4,296
Chicago, IL
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Ported 906 heads, 528 mopar mechanical cam, holley 750 and 10-1 compression (with your DB intake and HP manifolds). Should be pretty darn close.
2 kids and a dog
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Re: Stock appearing 425hp 383 possible?
[Re: Slant6pak]
#1319625
10/13/12 12:45 PM
10/13/12 12:45 PM
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Joined: Jan 2003
Posts: 10,010
Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 10,010
Frostbitefalls MN (Rocky&Bullw...
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If you don't mind going with 915 (1967 440) heads, you can build the motor with quench and pick up some tq/hp to get close to your goal. Another option is KB hyper pistons with a quench dome and use 906 or 452 heads. But the KB / 906 combo may need machine work to get it right. Set piston to head at .040. For pistons, look for a 1/16 1/16 standard oil ring pack. A proper bore and hone with torque plates is the right way to go along with file to fit rings. Set clearances in the bearings for 10w30 weight oil. I would recommend Brad Penn. You will need to get in touch with a good engine builder to come up with where the clearances need to be for that oil. Probably about .0015 to .002 should work. Use a crank scraper or windage tray, and a 1/2 inch pickup and 6 quart pan.
Compression should be set at 9.5 to 1 unless you live at altitude. The 528 cam is a good choice, and the mechanical cam will allow the rpm needed to get to your goal. If you have a choice, go with 1.60 rockers. Some hydraulic combos won't rev well enough. I have seen one that laid over at 5600 rpm. Lastly if you run an automatic trans get a 9.5 converter set to allow some stall, at least 3000 rpm to match that cam.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Stock appearing 425hp 383 possible?
[Re: HPMike]
#1319627
10/13/12 01:07 PM
10/13/12 01:07 PM
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Joined: Feb 2011
Posts: 4,302
Nebraska
72Swinger
master
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master
Joined: Feb 2011
Posts: 4,302
Nebraska
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Why is stroking out of the question?
Mopar to the bone!!!
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Re: Stock appearing 425hp 383 possible?
[Re: Slant6pak]
#1319629
10/13/12 01:40 PM
10/13/12 01:40 PM
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Joined: May 2005
Posts: 6,446
NJ-USA
HPMike
master
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master
Joined: May 2005
Posts: 6,446
NJ-USA
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Quote:
Quote:
Why is stroking out of the question?
My intake and exhaust manifolds are limiting factors... I don't want them choking the extra cubes. I'm also building a clone and starting with nothing... I could build a 440 if I wanted too, but I want the smaller displacement faster revving engine.
I hoping to fit the car with the one of the new Passon 5-speeds, with a 4.10 Sure Grip out back.
I'm also not opposed to aluminum heads vs. ported stock. I'm looking at "gasp" Stealth heads (I'm fully aware of their issues with valve locks) for no other reason other than that they appear fairly stock on the outside.
If you have no reservations about using aluminum heads then I strongly suggest you do. You'll get more power, more reliability for about the same amount of money(after you have a set of 906's ported and reworked with quality parts).
MB
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Re: Stock appearing 425hp 383 possible?
[Re: Slant6pak]
#1319630
10/13/12 02:18 PM
10/13/12 02:18 PM
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Joined: Jan 2003
Posts: 75,043
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,043
U.S.S.A.
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Quote:
Quote:
Why is stroking out of the question?
My intake and exhaust manifolds are limiting factors... I don't want them choking the extra cubes. I'm also building a clone and starting with nothing... I could build a 440 if I wanted too, but I want the smaller displacement faster revving engine.
I hoping to fit the car with the one of the new Passon 5-speeds, with a 4.10 Sure Grip out back.
I'm also not opposed to aluminum heads vs. ported stock. I'm looking at "gasp" Stealth heads (I'm fully aware of their issues with valve locks) for no other reason other than that they appear fairly stock on the outside.
I would build a 400 , but if you you are stuck on a 383 then you can do that with flat tops and CLOSED chamber heads , buy the stealths , CNC'd would be the best choice that way they actually flow as claimed. build for no more than 10.5 compression , with alum heads , otherwise keep it at 10.0 max with closed chamber iron , 9.5 if you use open chamber heads  , this will keep you pump gas friendly and make the power you want. I would use a flat tappet solid cam and ductile 1.5 rockers.
Andy F made over 550hp with stock iron manifolds , just pay attention to port mismatch with your heads so they aren't the cork you think for what you want to build.
Broken record time .... unless it's a CUSTOM PISTON ... no company makes a quench dome piston for a 383 ... no one ....
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Re: Stock appearing 425hp 383 possible?
[Re: JohnRR]
#1319631
10/13/12 02:51 PM
10/13/12 02:51 PM
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Joined: May 2005
Posts: 6,446
NJ-USA
HPMike
master
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master
Joined: May 2005
Posts: 6,446
NJ-USA
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Quote:
Quote:
Quote:
Why is stroking out of the question?
My intake and exhaust manifolds are limiting factors... I don't want them choking the extra cubes. I'm also building a clone and starting with nothing... I could build a 440 if I wanted too, but I want the smaller displacement faster revving engine.
I hoping to fit the car with the one of the new Passon 5-speeds, with a 4.10 Sure Grip out back.
I'm also not opposed to aluminum heads vs. ported stock. I'm looking at "gasp" Stealth heads (I'm fully aware of their issues with valve locks) for no other reason other than that they appear fairly stock on the outside.
I would build a 400 , but if you you are stuck on a 383 then you can do that with flat tops and CLOSED chamber heads , buy the stealths , CNC'd would be the best choice that way they actually flow as claimed. build for no more than 10.5 compression , with alum heads , otherwise keep it at 10.0 max with closed chamber iron , 9.5 if you use open chamber heads , this will keep you pump gas friendly and make the power you want. I would use a flat tappet solid cam and ductile 1.5 rockers.
Andy F made over 550hp with stock iron manifolds , just pay attention to port mismatch with your heads so they aren't the cork you think for what you want to build.
Broken record time .... unless it's a CUSTOM PISTON ... no company makes a quench dome piston for a 383 ... no one ....
An honest 425 horse on a legit dyno with a 10:1 383, exhaust manifolds, iron heads, and that intake is no easy feat...Not saying it can't be done, but it won't be like falling off a log. 
MB
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Re: Stock appearing 425hp 383 possible?
[Re: HPMike]
#1319632
10/13/12 03:04 PM
10/13/12 03:04 PM
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Joined: Jul 2006
Posts: 4,319
Puyallup, WA
StealthWedge67
master
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master
Joined: Jul 2006
Posts: 4,319
Puyallup, WA
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There's nothing about your parameters that would steer me away from building a 451. 440's make good power with stock manifolds, why not in a lowdeck block. Mine appears nearly stock and makes over 500hp. subtract headers and substitute a DP4B, and I'm right there in your wheelhouse. I'd go with a solid flat tappet cam in 250 - 255 duration range; use a set of Eddy or source heads (if you're truly looking for the stock vibe), and an 850 holley up top, and I guarantee you'd be in the ballpark and be reasonably streetable. Getting an honest 450 horse out of a stock stroke 383 will mean a much more high strung motor that won't be as pleasant to drive.
LemonWedge - Street heavy / Strip ready - 11.07 @ 120
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Re: Stock appearing 425hp 383 possible?
[Re: Slant6pak]
#1319633
10/13/12 03:12 PM
10/13/12 03:12 PM
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Joined: Feb 2005
Posts: 4,316
Prospect, PA
BSB67
master
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master
Joined: Feb 2005
Posts: 4,316
Prospect, PA
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The more cu. in., the better. Why? You can put a bigger cam in while retaining a stock like idle. Unless you are under budget constraints, it would be silly to use a stock stroke 383 if you are looking to maximize power. Here is an option: 451 cu.in Ported Stealth's 10.5:1 CR Custom ground cam Divider removed from DP4B 2 1/2" TTI and Ultra Flows Easy 450 hp with a hydraulic cam, and never open the hood again. Or 500 hp with an agressive cam. All on pump gas. 
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Re: Stock appearing 425hp 383 possible?
[Re: Slant6pak]
#1319634
10/13/12 03:14 PM
10/13/12 03:14 PM
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Joined: Aug 2003
Posts: 43,219
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,219
Bend,OR USA
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Quote:
Quote:
Why is stroking out of the question?
My intake and exhaust manifolds are limiting factors... I don't want them choking the extra cubes. I'm also building a clone and starting with nothing... I could build a 440 if I wanted too, but I want the smaller displacement faster revving engine.
I hoping to fit the car with the one of the new Passon 5-speeds, with a 4.10 Sure Grip out back.
I'm also not opposed to aluminum heads vs. ported stock. I'm looking at "gasp" Stealth heads (I'm fully aware of their issues with valve locks) for no other reason other than that they appear fairly stock on the outside.
In my opinion you are looking at the stroke wrong, the stock exhaust manifolds and intake limit the peak torrque and HP RPM,I would at least think of using a 440 crank on your build   That makes it act like a 426W Or better yet a 440 crank offset ground to 3.91 stroke and use the BB Chevy rod journal size and cheaper good quality H bem steel rods  The 400 block with either the 440 crank or the offset stroke 3.91 crank will make a really good combination for what your doing I've made 500+ HP with a pump gas 440 based stock stroke motor with iron heads a bunch of times, add a set of aluminum heads and 540 HP gets in sight very easily  Good luck on your build, it is very smart to think of what to do and use before starting 
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Stock appearing 425hp 383 possible?
[Re: HPMike]
#1319635
10/13/12 03:24 PM
10/13/12 03:24 PM
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Joined: May 2003
Posts: 6,566
Downtown Roebuck Ont
Twostick
Still wishing...
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Still wishing...
Joined: May 2003
Posts: 6,566
Downtown Roebuck Ont
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Don't write off a stroker just because you want to keep your manifolds. Just need to pick the right cam for the application. Displacement is your friend.  I would do the 400 stroked to 496. CNC Stealths with dished flat tops zero decked for 9:1. With a cam ground with HP manifolds in mind (see Dwayne Porter or AndyF) you should knock hard on 500hp/600ft/lbs and be all done by 5000 RPM. Nice street engine and only needs 87 regular gas to boot. Kevin
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Re: Stock appearing 425hp 383 possible?
[Re: gch]
#1319638
10/14/12 09:06 AM
10/14/12 09:06 AM
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Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
70Cuda383
Too Many Posts
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Too Many Posts
Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
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What kind of Hp are the FAST guys making with manifolds?
I also don't see any reason to NOT use a stroker. Total Hp may be the same, but with a stroker, you'll get that Hp at a much lower RPM and will be easier on the parts inside the engine
**Photobucket sucks**
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Re: Stock appearing 425hp 383 possible?
[Re: 70Cuda383]
#1319639
10/14/12 09:23 AM
10/14/12 09:23 AM
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Joined: Jan 2003
Posts: 7,327
Toronto (YYZ) Ontario
YYZ
master
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master
Joined: Jan 2003
Posts: 7,327
Toronto (YYZ) Ontario
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Quote:
What kind of Hp are the FAST guys making with manifolds?
I also don't see any reason to NOT use a stroker. Total Hp may be the same, but with a stroker, you'll get that Hp at a much lower RPM and will be easier on the parts inside the engine
I agree.
3.75-3.91 stroke won't hurt the budget and won't cause extreme stresses on the bottom end.
Plus the final displacements with either of those will be near enough to 440CI, which is what the stock heads were designed for.
Going to 484 or 500CI IMHO is a whole different ballgame....
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