Moparts
Modifying a cast 383 intake?
Posted By: torredcuda
Modifying a cast 383 intake? - 12/08/11 10:43 PM
`70 383 road runner being biult as a nice driver/occasional strip car.I have a fairly mild combo- 9.5-1,torquer cam(don`t have specs here) To look stock I plan on running the stock intake and exhaust manifolds and factory equipped Holley 4160 carb.It has a 727 and 3.23 gears behind it but a gear swap for track days is easily done with the 8 3/4 rear.What I am looking for is how to modify the plenum area for my combo and are there any other mods I can do like gasket matching etc.Extrude hone is out due to budget.
Posted By: dOrk !
Re: Modifying a cast 383 intake? - 12/08/11 10:46 PM
WHY NOT just a better alum intake ? Ex-Hone is so over-priced for the bennies ...
Posted By: dogdays
Re: Modifying a cast 383 intake? - 12/08/11 10:48 PM
Call Brzezinski Racing and ask them. They do a lot of cast iron work and are pretty helpful on the phone.
Is there an Edelbrock 383 intake that has a Mopar part number? You can always grind off the Edelbrock script. It all looks the same under the paint!
R.
Posted By: torredcuda
Re: Modifying a cast 383 intake? - 12/08/11 10:48 PM
Let`s see -I said I wanted to LOOK STOCK and cannot AFFORD extrude hone!!! Please read and try to comprehend a post.
Posted By: dOrk !
Re: Modifying a cast 383 intake? - 12/08/11 10:52 PM
Quote:
Let`s see -I said I wanted to LOOK STOCK and cannot AFFORD extrude hone!!! Please read and try to comprehend a post.
Well let's see ...if you can't afford EH ... then you can't afford any aftermarket service providers. And you can get many alum intakes that LOOK ENUFF STOCK ....
..ORE ...get a better paying job so you can afford EH .. 
Posted By: torredcuda
Re: Modifying a cast 383 intake? - 12/08/11 10:55 PM
I can modify the intake myself for the cost of a carbide and some sand paper drums or take it over to my buddy with a machine shop and have him do it for free.I plainly said I wanted to use the factory intake, I don`t know how to explain it any better???
Posted By: WO23Coronet
Re: Modifying a cast 383 intake? - 12/08/11 11:00 PM
I think they did comprehend your post, they're just trying to save you some hard work and headaches, some of the older Edelbrock intakes look stock once they are painted and the script is ground off, also the M1 dual plane looks stock, I think it even has the firing order on it. None the less, you could cut the divider out of your cast intake to open up the plenum volume, and just your basic port and polish, round off any sharp turns and mildly increase the volume. It is said that the later cast iron intakes used on the 400's are a better intake so maybe you should start with that. They are a spreadbore design so you would have to make an adapter to fit the 4160 to it and open up the primary side so there is no interference with the primaries hitting the intake. That's what I had to do when I put a 4160 on a 360 spreadbore intake, I made an adapter out of 1" thick aluminum plate, and had to mill/grind out the primary side so the primaries wouldn't hit.
Maybe some of the FAST guys will chime in because they are the experts on making the cast intakes work, although I can't recall anyone using a single 4bbl on a Mopar BB in FAST, but I'm sure there are some.
Posted By: dOrk !
Re: Modifying a cast 383 intake? - 12/08/11 11:01 PM
On a mild combo like you have ... I think what you are trying to do is wasted effort. I did the whole-ball-of-wax on a 440 TQ iron intake some time ago ...
I would have gotten better results doing something else .....LIKE ..
those exhaust mans .... now THERE you will see improvements.
Posted By: torredcuda
Re: Modifying a cast 383 intake? - 12/08/11 11:05 PM
Posted By: ademon
Re: Modifying a cast 383 intake? - 12/08/11 11:05 PM
I did a 340 and 383, you need a extra long style port kit. Then the porting is just common sense, lot of work and mess for MAYBE 3HP. Google porting, you should be able to comprehend it.
Posted By: scatpacktom
Re: Modifying a cast 383 intake? - 12/09/11 01:11 AM
To be honest if it were me I would leave the intake and exhaust manifolds off the table and spend the effort somewhere more meaningful,like the cylinder heads. You have to understand that when you monkey with the divider wall you are messing with the bottom end and with a stock stroke 383 with 3.23 gears that would be the last thing I would look at. A big engine with alot of stroke can hack it and you need to kill the bottom end.
You are about to go down a path that is labor intensive and filthy dirty all for something you butt may or may not notice. I would look elsewhere
Posted By: SportF
Re: Modifying a cast 383 intake? - 12/09/11 03:34 AM
Years ago in '68 I opened up the 4 individual holes in a stock '63 Dodge 383 and made an open plenum. Put it on and ran the whole summer with it. When I put a two barrel carb and manifold back on it for the winter I found that to have much more performance than the 4 barrel, seat of the pants kind of performance gain. I threw the modified 4 barrel away, it was a dog. I'd watch what you do, it didn't work out for me.
Posted By: sixpackbee
Re: Modifying a cast 383 intake? - 12/09/11 03:09 PM
I have to agree with Tom on this. I would do nothing more than a good inlet tract port matching. The engineers were pretty good at what they did back then. Most of the Chrysler intakes are quite efficient as is for a stock type application. Any meaningful modifications cost a small fortune.
Posted By: lewtot184
Re: Modifying a cast 383 intake? - 12/09/11 04:08 PM
Quote:
To be honest if it were me I would leave the intake and exhaust manifolds off the table and spend the effort somewhere more meaningful,like the cylinder heads. You have to understand that when you monkey with the divider wall you are messing with the bottom end and with a stock stroke 383 with 3.23 gears that would be the last thing I would look at. A big engine with alot of stroke can hack it and you need to kill the bottom end.
You are about to go down a path that is labor intensive and filthy dirty all for something you butt may or may not notice. I would look elsewhere
well said, good advice.
Posted By: JohnRR
Re: Modifying a cast 383 intake? - 12/09/11 04:56 PM
Jeff , I sent you a PM.
But I have to agree, the work that was done to that intake in the link is on a +500" motor that needs to kill some bottom end so the tires don't go up in smoke.
If you want it to LOOK stock you could find an old M1 dual plane, it's a copy of the 666 intake only in aluminum.
The stock intake has 4 runners with acute angle turns I can't imagine how that works out well ??? but the engineers must have knew something ?
Posted By: JohnRR
Re: Modifying a cast 383 intake? - 12/09/11 05:01 PM
Quote:
I think they did comprehend your post, they're just trying to save you some hard work and headaches, some of the older Edelbrock intakes look stock once they are painted and the script is ground off, also the M1 dual plane looks stock, I think it even has the firing order on it. None the less, you could cut the divider out of your cast intake to open up the plenum volume, and just your basic port and polish, round off any sharp turns and mildly increase the volume. It is said that the later cast iron intakes used on the 400's are a better intake so maybe you should start with that. They are a spreadbore design so you would have to make an adapter to fit the 4160 to it and open up the primary side so there is no interference with the primaries hitting the intake. That's what I had to do when I put a 4160 on a 360 spreadbore intake, I made an adapter out of 1" thick aluminum plate, and had to mill/grind out the primary side so the primaries wouldn't hit.
Maybe some of the FAST guys will chime in because they are the experts on making the cast intakes work, although I can't recall anyone using a single 4bbl on a Mopar BB in FAST, but I'm sure there are some.
NONE of the Edlebrock intakes look stock when painted, they are somewhat close but they don't have the choke stove mount and the coil is relocated so a holley wit ha dual feed line can be used. I have a DP4B which would be the best ebrock intake for the low deck.
Posted By: LaRoy Engines
Re: Modifying a cast 383 intake? - 12/09/11 05:38 PM
A stock intake manifold can be used. But how much flow does it actually leave on the table?
I tested a 906 head flowing 321 cfm @ .700" lift. Here is what happened.
Test (1), ported 906 by itself
Test (2), ported 906, 1968-69 383 manifold 2806301, port matched and mildly plenum blended & 4401S AVS
Test (3), ported 906, box stock 383 Victor intake, 4401S AVS
Lift........(1)...........(2)...........(3)
.100........71............69............69
.200.......150...........131...........143
.300.......209...........172...........203
.400.......257...........187...........234
.500.......292...........199...........259
.600.......313...........203...........273
.700.......321...........204...........273
With a good intake manifold you can get the same flow at .300" lift as you can with a port matched and plenum blended stock manifold at .600" and .700" lift. Start changing carburetors and the flows increase even more.
Posted By: dannysbee
Re: Modifying a cast 383 intake? - 12/09/11 05:50 PM
Hey Old Guy, your the man!!!!!!!!!!!
Posted By: ademon
Re: Modifying a cast 383 intake? - 12/09/11 06:11 PM
a 340 intake with about 25 hours in it. all of it done at my work on the clock, would not attempt another one on my time!!
.jpg "6958580-71Demon340(92).jpg")
Posted By: ademon
Re: Modifying a cast 383 intake? - 12/09/11 06:11 PM
2nd
.jpg "6958581-71Demon340(90).jpg")
Posted By: ademon
Re: Modifying a cast 383 intake? - 12/09/11 06:12 PM
last
.jpg "6958583-71Demon340(96).jpg")
Posted By: dogdays
Re: Modifying a cast 383 intake? - 12/09/11 10:42 PM
To the OP:
You are out of line.
1. Brzezinski does not do Extrude Hone, they get inside the cast iron things and work on them because the racers they service are limited to cast iron. Some they cut holes in or cut them in half to allow access. I suggested them because they are experts in making stock cast iron stuff work and because the times I have called them to ask a question about something they have been helpful and courteous.
2. Check my post, I did not use the words "Extrude Hone".
3. In your original post you said you wanted it "to look stock". You did not say you HAD to use the cast iron intake. I did read your post more than once.
Enough time wasted,
R.
Posted By: torredcuda
Re: Modifying a cast 383 intake? - 12/09/11 11:49 PM
Quote:
To the OP:
You are out of line.
1. Brzezinski does not do Extrude Hone, they get inside the cast iron things and work on them because the racers they service are limited to cast iron. Some they cut holes in or cut them in half to allow access. I suggested them because they are experts in making stock cast iron stuff work and because the times I have called them to ask a question about something they have been helpful and courteous.
2. Check my post, I did not use the words "Extrude Hone".
3. In your original post you said you wanted it "to look stock". You did not say you HAD to use the cast iron intake. I did read your post more than once.
Enough time wasted,
R.
I was a bit cranky the other day but my reply was not directed at you but the other poster who did mention ex-hone..I did state I wanted to use my stock intake.
"To look stock I plan on running the stock intake and exhaust manifolds and factory equipped Holley 4160 carb."
Posted By: BSB67
Re: Modifying a cast 383 intake? - 12/10/11 02:10 AM
It is not necessarily clear to us what you may or may not be flexible on. Like John said, the DP4B is not stock, but similar in that it is a relatively low rise dual plane manifold. My experiance is, other than some Mopar guys, nobody else will know the difference and it is a nice step up from stock IMO. There are little things that you can do to add power and performance in a stock package during a rebuild. Maximize the CR for the gas that you have, get the right cam, and put on the best prepared heads you can afford. If there is a larger carb that is acceptable to you, do that too.
Posted By: torredcuda
Re: Modifying a cast 383 intake? - 12/10/11 02:46 AM
I am not biulding the car for any specific class so I really have no rules to conform to but- "To look stock I plan on running(OK change this to WILL RUN) the stock intake and exhaust manifolds and factory equipped Holley 4160 carb."I don`t think the CH4B has a choke well so that kills the stock look?I am just trying to maximize the performnace of the stock components.