273 Commando Intake Rpm Range

[Slantsix64]

Hey guys what would the rpm range of the 273 commando intake be around? Was thinking of putting this on my 318 which probably wont pull past 5500RPMs is this a good torque and midrange intake?

 

[toolmanmike]

It will work for that. Aftermarket aluminum intakes like the Edelbrock LD4B work better. 1964-65 or 66 and newer?

 

[furrystump]

I assume you have the commando intake. If not I would go aluminum aftermarket dual plane for a 318. Whats on it now?

 

[trapster]

I think the 273 Commando intake was made to fit the smaller engine compartment and not actually made for performance. A Stock dual plane intake will probably outperform the single plane flat 273 intake.

 

[66fs]

Have one on our 73 Dart 318 with a small Mopar Performance cam and original 67 AFB. Runs great. They are a well thought out small port intake.

 

[toolmanmike]

I think the 273 Commando intake was made to fit the smaller engine compartment and not actually made for performance. A Stock dual plane intake will probably outperform the single plane flat 273 intake.

Ya I don't know if they were worried about hood clearance or not. Not really an issue. And the dual plane should work better especially at lower rpm.

 

[perfacar]

it'll go to 7000 rpm. we use to run 5.57 gear in stock elim. it didn't lay down.

 

[Wyrmrider]

Stock Eliminator- one of the few places where open chamber heads are superior to closed/ wedge chambers
what did you run for a cam
back when I was running we had to run a "stock" cam
which we "blueprinted" and retarded and revved the snot out of it

 

[mvh]

I don't know how much the intake had to do with it, but the torque and HP curves for the Commando were both very skewed toward the top end. So not perhaps a great fit for a "bottom end" motor. Look at these charts from the 67 Barracuda brochure (Commando at lower left)... the 318 probably resembles the 273 2bbl at upper right. This also makes me think that people who bolt the 273 intake and carb onto a 2bbl 273 are going to be disappointed — without the high CR and the cam it may be more show than go.

Edit: Here's the 68 318 2bbl for reference. It is somewhat more "high end" than the 273-2bbl, but a long way from the Commando.

View attachment 1715351205

 

[ValiantRacing]

Given a choice, i would run the LD4B

 

[66fs]

I don't know how much the intake had to do with it, but the torque and HP curves for the Commando were both very skewed toward the top end. So not perhaps a great fit for a "bottom end" motor. Look at these charts from the 67 Barracuda brochure (Commando at lower left)... the 318 probably resembles the 273 2bbl at upper right. This also makes me think that people who bolt the 273 intake and carb onto a 2bbl 273 are going to be disappointed — without the high CR and the cam it may be more show than go.
View attachment 1715351197
Edit: Here's the 68 318 2bbl for reference. It is somewhat more "high end" than the 273-2bbl, but a long way from the Commando.
View attachment 1715351203

View attachment 1715351205

I've run them on 273 2 barrel engines and 318's Both had smallish cams. Look at a Holley Streetmaster, very similar... The Commando 4 barrel intake works well on both.

 

[perfacar]

the cam was one of the first cam dynamics 7000 series. stock lift and duration. it would pull 7000 rpm easily. the lunati we had before dies at 6100rpm, used same springs.

 

[AJ/FormS]

I think my 71 Demon had a 2bbl single plain on it just like the early 273s. That thing went 5500 until the valves floated.

So Ima thinking the Commando will go as far as you put cam in it for,lol. What it does on the way there, I cannot say...... But hey you already own it so if you put reusable gaskets on it, it won't cost you a thing to try it. My FelPros are on the third cycle at least. Yeah I know, I'm such a tightwad; but if you never try something, you'll never find out. If you can figure out how to make babies, you can pretty much figure anything out...

 

[Wyrmrider]

we used to sell cam dynamics- good cams, crane has
and I think summit caries some of the crane versions
any idea the part number Pefacar
did we use that one as a cheater stock?
but if timing the same and more acceleration it would act like a bigger cam
stock with the long ramps gives you lots of wiggle room

 

[Wyrmrider]

give it a shot
hard to make more low end and midrange than a stock manifold (although the later TQ 4bbl may be "better"
al is lighter but IMHO not better till past mid range