Single Plane or Dual Plane? The Great debate!

[greymouser7]

I would like to ask a question.

When we talk about port velocity and volume and the effectiveness of each application, it brings up a question I always want to ask...

It reminds me of David Vizard's writing about using DIFFERENT size valves on four valve engines- say ford's modular 4.6/5.4 he compares using different size valves ( PolyQuad) to being as effective as variable valve timing. {page118 how to port & flow test cylinder heads}

-So if this is SO effective with "reduced fuel consumption and emissions, more low-speed output, and better top -end horsepower -

Why doesn't anyone run multiple (alternate size)small intake runners instead of one big fat one for each intake runner on the intake manifold?

 

[OldmanRick]

Like the old Offy intake....

View attachment a int.jpg

View attachment a int a.jpg

 

[greymouser7]

Like the old Offy intake....

View attachment 1714679920

View attachment 1714679921

Ahhhh!

Any good?

 

[RustyRatRod]

Not really. About like the D66. Useless as tits on a boarhog.

 

[fishy68]

Nice job Mike!

 

[greymouser7]

Not really. About like the D66. Useless as tits on a boarhog.

Off the top rope! Ba-bam!
"Ummmmmmm! Mommy just slapped daddy at the dinner table."

'Chuckling' You never pull your punches with my wild ideas do you Rob? I don't mind though, as long as you can put up with my interrupting. I just gotta 'know/learn.'

That variable valve timing stuff, the v-tec, ford's cam set up with new5.0, it's all very interesting to me.

 

[OldmanRick]

Ahhhh!

Any good?

My recollections were that the "dual port" intakes performed fairly well on big blocks that made torque and had most of their power in the 5500 rpm range an under. As far as the small blocks, just about any other aftermarket intake was better. Meaning in Mopar terms, a LD340 would clean it's clock....

 

[rumblefish360]

Hey Mike, do you find the runners smaller vs the RPM?

 

[MRL Performance]

Yes they are smaller, but not by much. The Stealth has way bigger runners than both

 

[moper]

MIke, what are the specs on that cam?

 

[fishy68]

Yes they are smaller, but not by much. The Stealth has way bigger runners than both

Have you ever tried a Stealth to see how they do on the dyno Mike? Particularly on strokers since you said they have larger runners

 

[DarrylsDart]

Why not use a SP intake and a annular booster carb?

 

[Kevin D.]

This thread is the bomb.All questions answered,Thanks Kevin.

 

[MRL Performance]

Have you ever tried a Stealth to see how they do on the dyno Mike? Particularly on strokers since you said they have larger runners

My Classic Cruiser 360's use them, they make good power 380/410. I have used them on strokers before, last one made 560/550 with a mild comp solid roller cam and a set of RPM's with a stage 2 port job.

 

[fishy68]

My Classic Cruiser 360's use them, they make good power 380/410. I have used them on strokers before, last one made 560/550 with a mild comp solid roller cam and a set of RPM's with a stage 2 port job.

Cool! So do you think they'd be better for use on a stroker than an Air-gap (either Eddy or Crosswind)? Thanks

 

[moper]

No reply on the cam Mike?

 

[mopar66]

mike / MRL ..
I am running one of the vintage Holley STREET Dominator manifolds on a warmed up 318 .. I know, not even stout enough to be on your radar .. but .. the guy I bought the manifold from ran in at the strip on the same motor that he ran an LD340 on, and he said with small runners used on the old holley Single Planes they actually were better in the low end torque range than some of the newer dual planes ??... any first hand info on this statement or comments ??

 

[rumblefish360]

Moper, he made a statement earlier about the cams.

 

[Hebrews10:26]

Why not use a SP intake and a annular booster carb?

The booster is about 1/2-3/4 long, the runners are about 12 inches.

Which one do you think will carry velocity longer?

If the booster was in the port window maybe you'd have something

 

[DarrylsDart]

The booster is about 1/2-3/4 long, the runners are about 12 inches.

Which one do you think will carry velocity longer?

If the booster was in the port window maybe you'd have something

So you are saying an annular carb will not help make more low to mid range power on a SP intake and only help very little if any on a DP intake?

 

[racerhog]

No reply on the cam Mike?

I think that info stays inhouse...

 

[moper]

I think that info stays inhouse...

Intake efficiency is directly related to camshaft choice and there's potential for tremendous differences in cams that have the same lift, duration, and LSA figures. So while I get the secretive business approach - I can't see where it might be a dangerous-to-business spec and it is critical to grasp the whole picture of the testing. When all that's posted is a result and "Same hydraulic roller cam" it's not enough information for any real discussion on the result.

 

[fishmens67]

The intake power differances could be build dependent.

x2 comparing apples to oranges.imo

 

[MRL Performance]

290/294
239/243
.550/.560
112 LSA
108 ICL

The 2 builds were 99% identical, the only difference was intake. 50lbft or torque at 3000rpm is a BIG deal, and its all in the intake, Im 100% sure of it. I have seen it many times, this is just the most recent.

 

[Abodybomber]

No complaints here,thank you for the information.