390 cfm vs super six

[273]

Itll never gulp 390 CFM but that little carb is pretty versatile. You can alter the springs in the secondary well and have them open when they're needed, but I bet its not too often. a paper clip on the actuator rod is an indicator of how far they open.
"....Let assume that we are going to upgrade a 225 CID engine is going to run at a maximum of 5000 RPM. With 100% volumetric efficiency (VE), we will theoretically need 325 CFM but, since there are pressure drops in the induction system, we will only need 244 CFM with a VE of 75% and 276 CFM at 85%. .."
Carburetion

That formula only guesstimates the cfm your engine actually uses. But carbs rating are arbitrary and don't line up with that formula.

Saying that 4bbl and headers are mainly for looks on a /6. Take any stock low powered V8 add cam 4bbl and headers and can gain a 100 hp or so depending on cam.

/6 20-30hp at best, head is the major choke point even then 100 hp is hard with a ported head.

 

[AJ/FormS]

Other hurdles to making Hp,for a normally aspirated slanty, are; 3.40 x4.125,long rods,and unequal length intake runners. Plus a really long crank.......,with only 6 cylinders on it. But they can make pretty good low-rpm torque.
If my Volare wasn't such a rust bucket, I might consider installing an 833-od and 2.73s for 65mph=1570rpm. I think the 9.5Scr slanty under the hood could do pretty good with that...... mileage wise.

 

[jbc426]

I ran a 350cfm Holley 2300 using an adapter plate that I hand blended to the Super six intake. The kick down linkage even worked on the transmission. The motor had larger valves in the head with some hand porting, and the head had been cut to increase the compression. I also ran a Dutra Dual set-up on it. All the motor work was performed by Doug himself. It was a great little motor.

One of the biggest performance and drivability improvements I made was to set the initial timing to around 22 and the total was limited to 32. I also had the vacuum advance hooked to manifold vacuum. The car absolutely loved the more advanced initial timing and would spin the rear tire and didn't have any gas knock.

It was still a Slant six though, never got more than 17 mpg and was pretty slow. I pulled the motor on a whim one day and went with a 5.9 Magnum instead. Best decision I ever made with that car.

 

[AJ/FormS]

On no, you didn't really just say that out loud, did you? You can't say that in the slanty forum,lol.
I can't believe 3 hours has gone by, and the silence is deafening.

I can't recall; does that 2300 have triple boosters?

 

[Darter6]

/sixchall, Can't say other than maybe. Mostly was there to mount my return springs to...

 

[Slantsix64]

I ran a 350cfm Holley 2300 using an adapter plate that I hand blended to the Super six intake. The kick down linkage even worked on the transmission. The motor had larger valves in the head with some hand porting, and the head had been cut to increase the compression. I also ran a Dutra Dual set-up on it. All the motor work was performed by Doug himself. It was a great little motor.

One of the biggest performance and drivability improvements I made was to set the initial timing to around 22 and the total was limited to 32. I also had the vacuum advance hooked to manifold vacuum. The car absolutely loved the more advanced initial timing and would spin the rear tire and didn't have any gas knock.

It was still a Slant six though, never got more than 17 mpg and was pretty slow. I pulled the motor on a whim one day and went with a 5.9 Magnum instead. Best decision I ever made with that car.

View attachment 1715229691

magnum swap sounds fun, i have three cars 1967 318 fish/1968 fish 4 speed 360/64 dart 225 four speed the slant six is the one that pulls the best mileage and can do a nice burn out although it takes alot more to have a great running tuned slantsix but the return investment is whats worth it.

 

[Slantsix64]

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[Slantsix64]

UPDATE
I'm really liking how much more power I have with this 500 eddy Avs. I ended leaning the secondaries to .86 jets I left the primaries alone. I'm getting 18mpg street driving but I know I can do better. I'm going to enrich the metering rods up. Hopefully that helps cause I'm getting signs of it running lean mixture at idle. Keep you guys posted.