Hello, i will soon be in a process of rebuilding the 383 motor in my Challenger, i will convert my car to a 4-speed at the same time.
Motor is a 67 383 with stock 906 heads, it currently has high perf stock exhaust manifolds and Offenhauser Dual Port intake. The car has a 3.55 rear end.
I would like to rebuild it to "a bit better" than stock specs, and more suitable to the 4 speed. I would like to keep the stock heads and exhaust manifolds but I thought about a different camshaft and single plane intake.
All the people having experience with beefing up a 383 for a four speed car are welcome :bradsthumb:
It's not going to do much good behind the 4 speed. :banana: :banana: :banana: :burnout: :burnout: :burnout:
If you're going to put one in front, the cam selection is an area to wake it up. Single plane good too, but don't over carb it. I'd talk to they guy at FBO for cam choice. Mike
Just corrected that :D
Who is the guy @ FBO ?
Building horsepower & torque with a 383 can be tough, the wrong cam will kill it... The biggest issue building cylinder pressure when you have such a short stroke... 906 heads have 90 cc chambers which means getting a compression ratio higher than about 7.5-1 requires a domed piston... Truly the best thing you can do is lose the 906 heads.... Get a set of 915 or 516 closed chamber heads..Now you can get 9.3-1 pretty easily.... With a little cylinder pressure the Crower 271HDP is a great cam for a 383, it features 222/234@.050 .486/.496 lift 112 centers......
FWIW 915's are hard to find & can be $$ but they get you compression without sacrificing any flow.. 516" are much more common & can flow plenty for a 383.. The compression will help allot more than the flow will hurt....
IMO the cam is the biggest and most important part of an engine build. It's the heart beat of the motor and will affect everything from how easy the engine is to start and how she drives. I could not be any happier with the Mr. Six Pack Cams that Bob makes. :yes: I've used them more times then I can count (at least 7 or 8 of them) and they always start easy and make a ton of power.... and all on pump gas! I build to about 9.3 to 1 compression with iron stock heads. I've done some 383's and they will make good power. Here's how easy his cams start (this is a 340):
[video]https://forum.e-bodies.org/gallerypics/videos/1_01_04_17_12_12_06.mp4[/video]
Thanks for your replies, sounds interesting. The fact is I am not 100% sure my heads are 906, what heads came with 1967 383s from factory ? How do I identify them ?
Where do i find those Mr Six Pack cams Cody ?
If it's original you probably have 516's.... The Mr Sixpack cam is always a good choice, mild, docile but makes good power....
Cyl head info... The casting numbers are in the same area whether its a 906, 915 or a 516... http://www.hotrod.com/articles/mopar-big-block-915-heads/
I've used the 906 heads and they are fine, but like stated above the 915 or 516 would be a better choice. Or you can do some 440 Source stealth heads. I've not used them myself, but people seem to like them and they look stockish.
Bob does not advertise so you have to contact him directly. You can tell him you are part of the E-Bodies.org site and that you know me. He'll take good care of you. :handshake:
mr6pk@hotmail.com
Bob Karakashian
248-477-7776 days
248-489-4076 eves
Cody, you should try a set of 915's some time.... You might decide the 906's aren't all that... On a 440 they are ok but the short stroke of a 383 creates a problem with the large combustion chamber volume... And the open chambers make building quench difficult & expensive...
FBO is at http://www.4secondsflat.com/
I like the Racer Brown Cams.
What about the intake manifold ?
I agree 100 % with @cuda cody
the cam s the key component in any build , I have been using the Lunati VooDoo series cams & they work extremely well also
You need to watch the RPM powerband of all the components used so a milder cam with a good dual plane intake such as the RPM may suit your needs best depending where you want the powrband to be for the use you intend
I think I may like better a "top end power" motor with the 4 speed and 3.55 gears too, but not too extreme though. Something that awakes around 3000 rpm up to 6000 would be cool.
The Weiand Xcelerator intake looks good and seems to fit under a rallye hood without any problem, I will search for a mild cam that suit fine.
Would you advise to keep a dual plane intake or go for the single plane route instead ?
Dual plane is more low rpm friendly typically but in the rpm range you are looking at either will work but I would look more at a single plane ,some are still a lot better than others are .
Lunati voodoo 703 can should work well
Yes, and what intake to choose with the Lunati cam ? It will need to fit under the stock rallye hood with the stock dual snorkel 383 air cleaner box.
Hello guys, I need feedback here : a friend of me is selling a pair of redone big block 452 heads including big Manley inox valves for a good price. The valve seats are all redone and the heads are straight.
Do you think it may match my setup ? I know there are late style heads but from what I heard they are pretty good and appreciated.
Can I reach 10.5:1 CR with the correct pistons ?
I don't know what are the actual heads on my 67 motor (906 ?) but I think they will need to be redone, so I plan to buy the 452 heads and the valves to put on top instead of the "old" heads.
What do you think of the 452 heads ? They come from a built 400 motor.
Have you purchased pistons yet?
Not yet Cody. I will purchase them later.
Those heads are open chambers/low compression, aren't they ?
452 were the last casting used on big blocks, thy do have induction hardened seats But you will cut through the hardening doing a valve job unless it is just a touch up
Second the 67 heads are closed chamber which is fr better for compression & quench , you may need to install larger valves as the exhaust is often the smaller 1.60 not the 1.72 But you can go up to 1.84 which I would do anyway ,install hard seats ,& yu have a better head .
So bottom line $$ spent on your 67 heads is a better investment
Quote from: Chryco Psycho on May 22, 2017, 10:14:33 AM
452 were the last casting used on big blocks, thy do have induction hardened seats But you will cut through the hardening doing a valve job unless it is just a touch up
Second the 67 heads are closed chamber which is fr better for compression & quench , you may need to install larger valves as the exhaust is often the smaller 1.60 not the 1.72 But you can go up to 1.84 which I would do anyway ,install hard seats ,& yu have a better head .
So bottom line $$ spent on your 67 heads is a better investment
:yes:
Thank you guys ! I will keep my heads :banana: :ohyeah:
Everybody has a personal preference on various intakes and combinations. For what your wanting I think you would be better suited with a dual plane intake. Like Performer RPM. Some of those open plane intakes really hurt low end torque. You don't want a pig at lower speeds. Some of the open plane intakes work great for drag racing when your launching at 3500 rpm. But on the street your taking off at 1000-1500 rpm. You need some low end torque also. Cams will also play a big role in whatever combination you decide to run. Here's a Edlebrock RPM in a 69 Bcuda with factory air cleaner. No clearance issues. The other motor on the stand is a 383 with a 496 stroker kit. Running RPM heads and intake.
Thanks Shane for your nice input. I actually didn't know the Edelbrock RPM could fit under a rallye hood with dual snorkel air cleaner box without any clearance problem.
I think I will keep my heads, and check what needs to be changed. Right now I have the Offenhauser Dual Port on top of my 383, what do they worth ? Will it make a difference going from this one to an Edel RPM intake ? You'll answer me : depends on the cam. I'd like to put a mild cam in there but I want to keep braking assistance at the same time and not too shaky idling (I have to watch the cam duration).
On the exhaust side I have two seperate 2.5 inch tubes and high perf big block iron manifolds.
I will also get a 650 cfm QuickFuel mechanical sec. carb to put on top.
The Offy dual port was an interesting intake but not one of the better performers , my top choice if you can find one is the Holley street dominator best of both worlds , you can still get them new for the RB but not the B engines .
Quote from: Sly on May 23, 2017, 07:12:12 AM
Thanks Shane for your nice input. I actually didn't know the Edelbrock RPM could fit under a rallye hood with dual snorkel air cleaner box without any clearance problem.
I think I will keep my heads, and check what needs to be changed. Right now I have the Offenhauser Dual Port on top of my 383, what do they worth ? Will it make a difference going from this one to an Edel RPM intake ? You'll answer me : depends on the cam. I'd like to put a mild cam in there but I want to keep braking assistance at the same time and not too shaky idling (I have to watch the cam duration).
On the exhaust side I have two seperate 2.5 inch tubes and high perf big block iron manifolds.
I will also get a 650 cfm QuickFuel mechanical sec. carb to put on top.
I have never messed with the Offy so I can't tell you much about it. The Rally hood has a big raised center section so I think it will clear everything. Maybe somebody will jump in that has run the RPM with rally hood. A body is a tight fit with no raised hood area and it clears just fine. On the cam you might be best to call Comp Cams and get their recommendation. If not I would recommend this cam. Just a nice all around cam. Nice mild lope at idle and good power from bottom to top. :alan2cents:
Quote from: Shane Kelley on May 23, 2017, 08:33:08 AM
Quote from: Sly on May 23, 2017, 07:12:12 AM
Thanks Shane for your nice input. I actually didn't know the Edelbrock RPM could fit under a rallye hood with dual snorkel air cleaner box without any clearance problem.
I think I will keep my heads, and check what needs to be changed. Right now I have the Offenhauser Dual Port on top of my 383, what do they worth ? Will it make a difference going from this one to an Edel RPM intake ? You'll answer me : depends on the cam. I'd like to put a mild cam in there but I want to keep braking assistance at the same time and not too shaky idling (I have to watch the cam duration).
On the exhaust side I have two seperate 2.5 inch tubes and high perf big block iron manifolds.
I will also get a 650 cfm QuickFuel mechanical sec. carb to put on top.
I have never messed with the Offy so I can't tell you much about it. The Rally hood has a big raised center section so I think it will clear everything. Maybe somebody will jump in that has run the RPM with rally hood. A body is a tight fit with no raised hood area and it clears just fine. On the cam you might be best to call Comp Cams and get their recommendation. If not I would recommend this cam. Just a nice all around cam. Nice mild lope at idle and good power from bottom to top. :alan2cents:
First on the Performer RPM, with a 383 it will fit but it's close, if you don't set the snorkels right it will rub paint off the bottom of the hood.....
Second that cam in a 383 is gonna be a pig.... With the short stroke 383's don't like allot of duration... If you want a motor that doesn't do much till 3500 rpm's use it, otherwise keep the @.050 number down in the 218-224 range..
:iagree:
There are far better cam choices now than the MP Or Comp
A Lunati Voodoo or Crower will be a better choice