dual plane vs single plane?

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V8-valiant

V8-valiant

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im considering switching from a mopar m1 dual plane to a edelbrock single plane what performance changes will i see?
 
generally, you'll kill a little bottom end torque and pick up some top end horsepower. A performer rpm is a good in between.
 
Can you share the specs on your motor and what kind of rpms you plan on seeing and what you are looking to do with the car?
 
the car will see track and street, its a stock 360 other than
9.8 kb 107's
292-480 lift lunatti cam
spitfire headers
4 speed
3.55's



thanks for all the help guys
 
single planes have longer runner length,if you go by the point where the dual plane port runs into another one-[have a look on the bottom of manifold] 440 are bloody grunters , 1 reason is their intake runner length ,so you can get
more grunt out of a single plane iff the runners aren't too big ,as well as hp.
hot rod magazine did a test on a stock clevo and dynoed it then fitted a
single plane with reasonable runners [slightly big] and produced the same torque at 2400 rpm as dual plane and 60 hp.more on top, also as duster don said the performer rpm is also a good choice,iff you have wheelspin problems
with the torque you've got then putting a large runner single plane will kill a bit of torque at lower revs and give you more hp. up top and the faster you are going [as you build up revs] the less likely you are to break traction-ken
 
V8 Valiant, the 440 is a fine piece of iron, but a little large for an A-body and a little difficult to install therein, IMHO. However, if you are determined to install it in your Valiant, I can refer you to a step-by-step "how-to" article, specifically on the subject of how to install a big block into an A-body, that appeared in Car Craft magazine in December of 2000. The article used to be online, but I'm not sure if it still is. If you can't find it, let me know and I can fix you up with a copy.
 
You would have to get a well thought-out single plane to be able to pickup all around like he mentioned. A not too big port single plane may help. But usually steeper gears will help makeup for some lack from a single plane. Given you have only 3.55's i wouldn't.

Volume vs. Velocity comes into play dealing with intakes. Single planes, have lots of volume. Not split in the plentum, runners are usually short and fat. Low velocity, high volume. Which means your low end will suffer, where as the top end will scream due to the extra volume in the plentum waiting to be used. You also will likely need to spin a higher rpm to gain the most out of the single plane.

Your downfall i'd say is the 3.55s, given a 4speed. thats good. It'll take longer for the powerband to hit than if you had, say 4.10s.

Dual Planes, have short and long runners. Long runners offer low rpm velocity which will give you your low end torque. Where on the top end the shorter runners will be most efficient. This is what your common street car usually runs like yours.

If i were you, i'd run a Edelbrock Air-Gap intake, with a 650/750 Double-Pumper. If you had a nice set of 4.10s, bigger cam and some ported heads, i'd lean twords the single plane.

Just my 2cents!
 
I don't think you've got the combo to get the full benefit of a single plane, like taller gears and more cam and like Don says your bottom end will suffer. If you do decide to change try a 4 hole spacer sometimes this will help the bottom end response.

Terry
 
It depends on what 4 speed hes using. Early 4 speeds and over drive 4 speeds had a real low 3.09:1 first gear. I dont think you would hurt to much of your low end with 355s and that deep 1st.
 
Have you done any mods to your present manifold and carb?
What are you hoping to achieve by the change?

I like single planes with a smaller cfm carb in a dual purpose car, but you really have to match and tune the carb to get its potential or it will be lazy on the bottom end.
Cam shaft and valve timing play an important part also.
Properly done it will smoke a dual plane hands down everytime.



A daul planes usually splits the carb into 2 sides, sort of a 2bbl per side at WOT, 1bbl at partual.
A single plane allows full carb flow to all cylinders at WOT. 2bbl at partual.
 
Theres been a few shoot outs where they switched a rpm air gap for a m1 single plane,the tests were back to back for h.p. and e.t. and the differnce between them was minimal.Your peak torque will not decline with the single palne but you will trade around 10-15lbs ft. on the bottom for 10-15 h.p. up top-at the track its barely noticeable on a average 12second car.On the street it will feel alot more significant since off idle drivability will be a bit more soggy.The m1 is not a full race manifold like a victor,it still retains a decent velocity and runner legnth and its modeled after the old strip dominator.If it were me with your combo I would stick a rpm air gap on it.
 
I would stick with what you have.

as others mentioned, the single plane would be better with steeper gears.

As for swapping the M-1 for an Airgap, I doubt the minimal power gains alone could warrant spending another $200+ on an intake...unless every HP counts.
 
Stick with what you have your build is way too mild to ever need a single plane intake..
 
I think you could improve with a better dual plane. The M1 is not any better than a typical stocker, and i dont think as good as the iron '71 T quad factory intake. But it is lighter and prettier. The first single plane I'd use would be the M1 single, and I think it would be too soft low down for you. Dual planes have longer, smaller runners, and by the nature of the plenum divider help the low end carb signal. Dual planes usually have shorter, more direct paths, with larger cross sections, and larger plenum volumes to help maximize the mixture flow thru the carb/ports at WOT. Small tires, 3.55s, and a cam that will pull past 6K could use a better dual plane like the Air Gap.
 
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