I'll read it, but i don't need to.

I've run a quazzilion of both type of intakes and studied them, obviously.

I'm doing this 'questioning' as more of a mental excersise for people. Just like to see what people assume vs actually know. And not on a matter of who's smarter than who...I don't get into that...more more of a matter to see thoughts, theories, and more importantly assumptions vs data from real world use.

That's all.

It was 26*F here this morning (prob same for you) and thus physical boating is done...but mental continues. LOL.

So lets change the subject and talk about a single plane manifold. 2nd part of my post. Why does the HP 500 come with a single plane verse a dual plane. Top rpm on an hp 500 is 5200- 5400 These single plane manifolds just start working at 4500 rpms and are good to 8000 rpms. My dual plane is good from 1500- 6800 rpm. Can someone explain?

#1: Cubic inches changes things.
#1.5: Manufacturer states an rpm range as help, however thry don't know if you are installing it on a 396, 454, 502, 540, 572, 598, 632 or ??? and add to those the countless different possibilities of cam heads, compression, torque converter (or direct drive), trans gear ratios, rear end (outdrive) , exhaust, and etc,etc. Not trying to make this more difficult than it is...but it all plays a part - some more important than others. cid, cam, and heads together make a massive influence on what to get.

#2: Not all single plane intake manifolds are created equal.
- Runner cross sectional area
- Runner Length
- Plenum size

#3 Who wants to see a car intake on a blue motor ?
A single plane says 'Race' and blue motors are 'mercury racing.'

Again, 500cid's with high lift cam and heads with big valves requires a bunch of air. The dart single plane 4150 intake has conservative plenum and runner sizing, so it works quite well in this application.

Put on a Super Victor or Super Victor II and things won't work out so well.

http://i.ebayimg.com/00/s/MjIzWDMwMA...s0!~~60_35.JPG

BTW: great info Mr Maine.

PSst: always great to see another involved sbc guy around here.

ok so my 509 490 hp engine with a crane cam 547 lift 224-234 duration, oval port 781 heads with large econel valves and a nickerson custom built 930 cfm carb will have to stay with a air gap dual plane intake.

really,,you know this as fact,,because I have a few engines that say otherwise.and a couple were 454's.and the jr's were ported for the 454's too.
I've heard this argument since 2001 when I built my 502 for my truck.w/ the boat in tow I could blow the tires off that thing,,my only regret,,putting in a whimpy azz cam 218,222 less than 600 lift.

oops,,II's turned into jr,,damn narcotics shot in my back yesterday.<lol>

damn this site is messing up posts.

SB must be editing cause I keep posting above his original.

LOL S30.

I did not mention Vic Jr's.

I wrote Super Victor and Super Vic II's.

Way different manifolds - other than being single planes.

Has any body tried the new super victor II on a 500 inch or larger engine? I looked a one at Summit last week and the runners are huge!