Intake manifold swap? Worth swapping to a Performer from stock?

[TBass]

Hey fellas! Another one of my "I need your opinion" posts here.

I am falling victim to the hard restarting caused by the crossover in my OEM intake. It's absolutely wearing me out! I want to stay with a stock intake because it just fits with the kind of build I went with. I have an air car and with a Performer intake, my A/C compressor brackets won't bolt on. Allegedly the Performer really doesn't flow much better than stock anyway. I tried to swap into a 750 carb today and it wouldn't even run for more than a minute before it flooded and died. So, I went back tomy crappy 1406. It is running rich as hell even with me leaning it out with metering rods and spring changes.

Having said all that, I have an Edelbrock 1406 and 1411. I also have the tuning kits for both and the Performer intake which also has the stupid crossover ports in it. I have no issue with swapping to the valley pan that will block off the ports, but my real question is; Do I switch that manifold? I had a 1/2" phenolic spacer under my carb, but it was conflicting with my throttle plates so I took it back off. Now the carb is right on the intake. Should I return the 1411 and get the 650 AVS? I'm staying with an Edelbrock carb regardless so the "Buy a Holley guy" need not chime in on this. Just sayin'! If I were running lots of RPMs I would run a Holley carb. But I ain't doing that. My biggest issue with getting things "right" is dealing with this stupid heat crossover. It's absolutely killing me!

 

[Garys1969RR]

Need a few more details before we can give you anything close to a good answer. First, what size engine r u working on? Sounds like a 318? Also, there is an older one called the 383 Performer, 440 Performer, and the newer Performer RPM. Which one do you have?

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Not sure if there is a 318 Performer.

 

[TBass]

Oh hell! Sorry. It is a 383 with a VooDoo 60302. This the first time I have even remotely tried to keep things looking somewhat stock under the hood and it is working my butt off more than any of the radical stuff I have built in the past. Essentially the only things I have done are the cam, headers and MP electronic ignition conversion. Nothing fancy.

The intake is the 383 Performer. I think it is a PN 2186.

 

[Garys1969RR]

I think the Performer RPM is a better intake than the stock one. If it is difficult to start, I would double check all the tuning specs. Set initial timing to around 15 to 20 degrees before TDC. Maximum of 38 degrees at 2000 to 2500 RPM. Check your pick up to wheel clearance in the distributor. Should be .008" Make sure the plug wires are all good, as well as the spark plugs. Make sure your cam is installed in the correct position. Do all that, then move on to the carb if you are still having trouble starting it.

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My 65 Belvedere 451 was hard to start when I got it. Found out the cam was 20 degrees retarded, pick up wheel and reluctor in the distributor were wore out. Must have been hitting at some point. Now it starts soon as you turn the engine over, every time! And I did swap out a few carbs and intakes before I found the real problems.

 

[TBass]

I have been through all that stuff. I have worked the bugs out of everything except this heat problem. It fires right up until it reaches operating temp. It seems as though the engine itself is at 180 degrees but the center of the intake is the temperature of the sun. I am ordering that valley pan regardless. Just unsure about which intake is going to be on top of it. Until I realized the aluminum one had open crossovers, there was no real question. Once I flipped it over and saw that, I had to come ask for opinions. It is definitely going to look out of whack in the engine compartment to me since everything else looks like it's still sitting at the local Dodge dealership in June of '66.

 

[sleepar]

X2... you could put a suitcase of money into a car and never run right.. a $10 part and go 100,000 miles without a hitch... triple check everything get real comfortable with everything how it works etc... I have gotten things running that wouldn't expect to run with a little bit of time and effort... figure out where its weak

 

[Meep-Meep]

My 440 runs high 12's with a stock intake, 750 AFB, iron heads and a .455 / 272 cam so I guess I'm not saying one must dump the stock intake to have good performance.

The hot start issue is a major problem these days and it's really the fuel. Anything you can do to keep the carb cool during the heat soak period will help.

 

[UKPlymouth]

I know what you said about carbs, but I just bolted on a Street Demon 750, the new one that looks like a Thermoquad. Has the plastic central body and runs perfect out of the box. Hides nicely under the stock snorkel type Mopar air cleaner too.
When I had an iron manifold and Edelbrock carb it boiled fuel all the time.
Not now.

 

[TBass]

I had considered that Street Demon carb too. It has a great reputationso far. It is a massive carb. I am just familiar with the AFBs. I owned a 650 AVS once too and aside from it not flowing enough on that 351, it ran great. If I can figure out how to cool things down and stop flooding so easily, I can determine which carb to go with. This inake is a four hole. If I were to switch to a Street Demon I am not certain the secondaries will open. I mean, the 750 functions properly with the small spacer I have, but the 600 I have been running doesn't. It has smaller primaries than secondaries, but I dunno if they are really considered to be spreadbore since the difference is slight. I just know it conflicts.

 

[440 Cuda]

Which OEM Intake Manifold is on the 383 ?

#301 666 968 {1967 and earlier Casting}
#2806301 {1968 and 1969 Casting}
#2951666 {1970 and 1971 Casting}
#3614046 {1972 and later Casting}

 

[sleepar]

Holley makes a spread bore that is a lot more tunable.. I like edelbrock for good mileage and the thermoquad set up is good for vapor lock... there is no real better or worse carb its about what works given the situation....

 

[splicer]

You're absolutely cooking that carburetor...no matter what intake or carburetor you run, make sure you get a phenolic or wood spacer in there or the carb will overheat, boil the fuel, and make hot starting extremely difficult...even with blocked crossover the manifold will quickly get as hot as the rest of the engine and cook the carb..

Splicer

 

[TBass]

I have the phenolic spacer still. I plan on putting it back on the manifold when the AVS shows up. I don't know the casting number off the top of my head. I believe it was from a '67 383. It still uses the small bolt pattern on the mounting pad and the spacer I have is the only one I have found that lines up correctly and uses that pattern. I am just hoping that AVS doesn't have any fitment issues with it like this AFB does. I also have the 1214 valley pan on the way to get those ports blocked off. It's entirely too hot out here in the central plains for that. I have never even given it a second thought on any of these engines until now. Can't even get a decent tune on anything like this. I am good for a short cruise to the end of my street right now. That's about it.

 

[440 Cuda]

Question

#1
Instead of installing the 'new' Valley Pan, why didn't you install {slide in} copper 'shim stock' in between the Intake Manifold and Cylinder Head 'cross-over passage' to see if there is any change in heat.

That is a quick and simple 'trial' test, without pulling off the Intake Manifold.

#2
The early-style 383 Intake Manifold {#301 666 968} has a lower profile than the later Castings, and
tends to run hotter, as it has 'huge' heat cross-over passages.

#3
The 1968 and 1969 Casting {#2806301} is by far the best OEM 383 Intake Manifold.

#1 > It has a taller Carburetor Mount Base
#2 > It has 'smaller' heat cross-over passages.
#3 > It has 50% greater branch length in the runners.
#4 > The port dimensions are 10% bigger.

 

[Dennis H]

The Edelbrock RPM Perfomer on mine was part of the rebuild package along with the 850 Demon. The 1/2 inch spacer only fits because of the power-bulge hood. The best things going are the coated TTI's that keep the underhood overall temp 100 degrees lower than others without coated headers. I still experience heat soak and challenging hot re starts under certain conditions, like 92 degree Reno heat at 5000 feet. 440. Don't care about looks, I prefer reliability and performance.

 

[440 Cuda]

383 Intake Manifold Height {Center Carburetor Area}

* #2205968 ~ {1962 thru 1967 '383'} .......... 2.80"
* #2806301 ~ {1968 and 1969 '383'} ........... 3.44"
* Edelbrock Performer ~ #2186..................... 4.00"
* Edelbrock Performer RPM ~ #7186.............. 5.35"

 

[Gpuller]

Get the heat risers blocked off with the Fel-Pro gasket. Put on some sort of carb spacer/insulator. Also if you have steel line from fuel pump to carb your going to have to have that insulated.
Keep your Performer because your A/C brackets probably wont work with any other intake like a Performer RPM.
Can't help you on the carb, I'm a Holley guy so I'll shut up. lol

 

[440 Cuda]

Take a look at this 383 Intake Manifold {1962 thru 1967} Casting #2205968

Massive Heat Cross-Over Passages

 

[TBass]

Gpuller......you're killing me! LOL!!! I have had entirely too many days suffering from those ole "Holley blues" trying to get them to adapt to the constantly evolving Oklahoma weather. Ain't nobody got time for all that! If this was a four speed, I would consider a Braswell double pumper or something, but it isn't. Those 3310s are aggravating as hell even when they are working "good enough".

I verified my P/N on the intake and it absolutely is that 2205968. I don't think I can use my A/C brackets on any other intake though. The way they run over the intake runners kinda limits me. I am 95% certain they won't fit with the Performer that I have. As I said earlier, this 2186 has open crossovers as well, so swapping to it may not achieve much more than elevating the carb more. Aluminum might gain me a bit more in temp reduction, but I am feeling that blocking those ports is key. It HAS to help!

 

[kb67mopar]

Gpuller......you're killing me! LOL!!! I have had entirely too many days suffering from those ole "Holley blues" trying to get them to adapt to the constantly evolving Oklahoma weather. Ain't nobody got time for all that! If this was a four speed, I would consider a Braswell double pumper or something, but it isn't. Those 3310s are aggravating as hell even when they are working "good enough".

I verified my P/N on the intake and it absolutely is that 2205968. I don't think I can use my A/C brackets on any other intake though. The way they run over the intake runners kinda limits me. I am 95% certain they won't fit with the Performer that I have. As I said earlier, this 2186 has open crossovers as well, so swapping to it may not achieve much more than elevating the carb more. Aluminum might gain me a bit more in temp reduction, but I am feeling that blocking those ports is key. It HAS to help!

unless you isolate the carb from the heat of the intake it does not matter what intake you run and what carb you run. You need to isolate the heat flow path from the engine to the carb. Without a spacer made of a low heat conductive material the intake will heat soak and then heat soak the carb. Gpuller said all the right things...