All for .370 lift and under ........

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Deshroud the chamber and have a 15 top cut added to the 30, that will increase all your .100-.400 numbers.
Basically... have 5 angles with the lower @ 75.

When you want strong flow numbers .400 lift and below with this head.. add the 15. If you want great peak high lift #'s and just 'good 'below ...stop with the 30. This is in regards to the 302 head. Every head is different.
 
My buddy had a 550 cfm carb on a Buick 401 Wildcat. The thing was snappy as heck for a land yacht. Didn't need high rpms or a big carb with those low rpm torque figures. The lawnmower carb worked but didn't get him more mpg. It just got him nothing past 3000 rpm.
 
pishta said:
My buddy had a 550 cfm carb on a Buick 401 Wildcat. The thing was snappy as heck for a land yacht. Didn't need high rpms or a big carb with those low rpm torque figures. The lawnmower carb worked but didn't get him more mpg. It just got him nothing past 3000 rpm.
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I always liked that 430.
Most buicks ran smaller carburetors, the port volumes were small too...hint.
 
RustyRatRod said:
.370 lift? That would be tiny even for a stone stock 2 barrel.
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Stock 318 2 barrel cam: .373 intake .399 exhaust and 240* intake 248*exhaust. A tad bigger cam something like a 360 2 barrel would get you good results. Back cut the valve's .030" by 70* seems to help low valve lift flow. Clean up the bowl area.
 
318willrun said:
in todays world, as it was before it took off like an old man even if my son was driving it !!!!! The van has a lot of pedal and not much response !!! :D
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Running 1 1/2" primary tube headers with a 2 1/4" exhaust system will scavenge the combustion chamber not only faster but more complete. A better set of rocker arms something like the 273's use for a more accurate valve lift
 
Dan the man said:
Running 1 1/2" primary tube headers with a 2 1/4" exhaust system will scavenge the combustion chamber not only faster but more complete. A better set of rocker arms something like the 273's use for a more accurate valve lift
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true. On this particular project, we are sticking with manifolds and the stock rockers.
 
Using the correct 4bbl is likely to give better fuel economy than a factory 2bbl intake & carb.
You buy an Edel Perf [ not RPM ] or similar which has been optimised for the idle to 5500 rpm range. Compared to the factory low performance 2bbl intake, it will have more efficient runners/plenum that in itself will provide better economy.
The 2 bbl is a compromise. Throttle bores need to be large enough so that the higher rpms can be reached; this will compromise low speed/cruising economy. Using a small a small 4bbl of 450-500 cfm will have small primaries for better economy; if power is needed, the secondaries are there....
 
Bewy said:
Using the correct 4bbl is likely to give better fuel economy than a factory 2bbl intake & carb.
You buy an Edel Perf [ not RPM ] or similar which has been optimised for the idle to 5500 rpm range. Compared to the factory low performance 2bbl intake, it will have more efficient runners/plenum that in itself will provide better economy.
The 2 bbl is a compromise. Throttle bores need to be large enough so that the higher rpms can be reached; this will compromise low speed/cruising economy. Using a small a small 4bbl of 450-500 cfm will have small primaries for better economy; if power is needed, the secondaries are there....
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This^^^
A properly size 4 barrel will always get better mileage if you mostly stay out of the secondaries...for the reason above, smaller primaries..better mixing
 
MOPAROFFICIAL said:
This^^^
A properly size 4 barrel will always get better mileage if you mostly stay out of the secondaries...for the reason above, smaller primaries..better mixing
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I have learned a lot from being on this forum, I thank everybody for not kicking me off of it as I'm sure that a couple of times I had it coming to me.
 
I'm well aware that I could put a 4bbl and all, but on this project we are working with the 318 2bbl components.
 
I remember trying out a 318's 2 brl carter on my built up 227/6....leeeeeeean..

Tried a Rochester 2g off a 69 307... riiiiiiiiich.

Got me a holley 350 cfm.... purrrfect.. right out of the box with the exception of the pv too low a rating.

An idea ,diff motor, but still an idea on calibration.
My slant head flowed about 190cfm
318 heads stock are like 175-180cfm 'before the intake goes on'..then its worse.
I've taken a ported 302 and bolted a iron 4 brl intake to it...148 ish cfm with clay on the carb flange.

That's where I would start digging for power, the intake manifold.

Best of luck
 
318willrun said:
I'm well aware that I could put a 4bbl and all, but on this project we are working with the 318 2bbl components.
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Which factory 2 bbl intake is better?
I have seen the single plane ones and dual plane ones.
Do you know why they had both?
I'm kinda doing the same thing as you are only with an A-Body just for fun...
 
the first 318la and later (66thur 69) 273 2-barrel shared the same single plane intake .the port is a little smaller and keeps air speed up.
 
Dartnut said:
Which factory 2 bbl intake is better?
I have seen the single plane ones and dual plane ones.
Do you know why they had both?
I'm kinda doing the same thing as you are only with an A-Body just for fun...
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Honestly, I'm not sure there is a clear winner for the 318 2bbl intakes. HP ratings were all about in the same. We've ran the 360 2bbl intake/carb on 318's and that is a difference you can feel by the seat of your pants.
 
Besides what I did at home with a dremel to remove turbulance... at the machine shop today, heads are about done, Monday maybe? Machine work included 3 angle valve job, back cut valves and under seat (25 degree in the name of low lift flow), valve springs will be at 90 lbs seat pressure, should reach 250 over the nose with the factory cam. Heads are cut .030.
Hopefully we get the results we are hoping for..... Hopefully :)
 
Dual n single. I had it in my mind they were all single plane for some reason.
 
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There was a single plane. I did a little work to the factory intake from this 318, but not much.
 
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Add a bung to the exhaust for an air/fuel ratio gauge on the dash. CC the combustion chambers for equal size. Remove any sharp edges or casting flash. Do a gasket match on the exhaust manifolds. Do a little exhaust port smoothing. Run a few more degrees of initial timing. Play with the carb jets and distributor advance later. Keep us informed.
 
Picked up the heads today.... I will show the details soon. I'm very excited to see how this unfolds. By the way, this project is laying the foundation (of do or don'ts) for an upcoming project.
 
318willrun said:
There was a single plane. I did a little work to the factory intake from this 318, but not much.
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Yep, not much to do. Just gasket match it and go maybe 3 inches into each runner, check the size of the carb flange holes and open if necessary..maybe blend the lower angle of the flange/plenum. Whatever you can reach..if we are talking dual plane..hey maybe put a little notch, like 3/8-7/16" and about 1/2" deep...or a 3/8 thick 2 hole spacer and notch it instead. Get a 2'fer out of that..mid range tq and more rpm capability. That's where I'd start.
 
MOPAROFFICIAL said:
Yep, not much to do. Just gasket match it and go maybe 3 inches into each runner, check the size of the carb flange holes and open if necessary..maybe blend the lower angle of the flange/plenum. Whatever you can reach..if we are talking dual plane..hey maybe put a little notch, like 3/8-7/16" and about 1/2" deep...or a 3/8 thick 2 hole spacer and notch it instead. Get a 2'fer out of that..mid range tq and more rpm capability. That's where I'd start.
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I've cut the divider down, dulled the corners, on the underside also.
 
The best way to increase fuel economy and performance is to lose weight.
The second best way is to improve aerodynamics.

By starting with that van, you've shot both in the foot.

I really missed seeing posts like this from 2008.
Not.
 
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