TheZaZ

I am about ready to order an intake manifold for my motor.

My 86 camaro needs a new hood so I am going for a 2" fiberglass good. (I dont really want to go with a higher cowl hood)

Just trying to figure out if a single plane victor jr or similar manifold will fit (no carb spacer) or if I should go with a dual plane air gap or similar.

Any help is appreciated.

Night rider327

iTrader: (13)

What's your engine combo? Most people will not need a single plane intake, and in most cases the single plane ends up being slower.

I have had a few diff intakes/carbs on mine with diff hoods/scoops.. A performer RPM intake, 1" spacer, holley 4150 hp, and 3" air filter on a drop base fit under my 2.5" stinger scoop.

TheZaZ

355 sbc
11:1 compression
200cc aluminum heads (coming from Speier Racing heads)
236/244 .491/.497 110lsa cam (not a roller) (3000-6800 rpm range)
Speed Demon 650 carb for the time being.

Not set on stall converter yet, but looking at around 3000-3500 range
Car has stock 3.23 rear end but I will be swapping in a bolt in ford 9" with around 3:73 to 4:11s over this winter.

Running a Turbo 400 tranny as well.

Hopefully that was enough info.

Night rider327

iTrader: (13)

I would stick with a good dual plane on that one if it was me.

Mine is very close to yours
10.34:1 355
Brodix IK 200 heads
249/252@.050", .570"/.579" lift, 106 LSA solid flat tappet
Holley 4150 HP, 750 dp
9.5" 3500 stall
th-400
Ford 9" 3.89 gear

I'm still running a dual plane. Like I said in my other reply I'm using a performer rpm intake that I re worked. Port/gasket matched, milled the center divider wall down 2" long x 1" deep, added a 1" open spacer.

I'm at the point where I keep going back anf fourth on the above vs. a single plane but I keep thinking of all the dynos my old shop did, and all the track testing I done on other combos and I still feel like I don't have enough engine to take full advantage of a single plane and would kill off my lower/mid rpm torque and that would slow the car down.

If it was a full on track car only then I think I would gear it deeper, add in more stall and put a single plane on it and of course be faster then.

Watch this vid. Good dyno test of victor jr vs rpm air gap and air gap vs rpm

TheZaZ

Well....

You just made my decision REALLY easy. Dual Plane it is.

I was looking at these Dual Planes:

Performer RPM
Performer Air Gap
Weiand Speed Warrior (similar to air gap)


I could do the mod like you did to yours really easy. My buddy has a machine shop so cutting out that divider is no big deal.

Which would you recommend or would it not make much difference between those three?

skinny z

I have a GlassTek 2" cowl hood. With an RPM Air Gap, a filter base that's dropped 1 1/4" and a 4" x 14" filter element, I can see through the cowl opening that's there's about 1/4" of clearance. That's at the leading edge of the lid where it bulges up (see pic attached). I looked up intake manifold dimensions on the Edelbrock website. The Victor Jr measures in at 4.58" and the Air Gap at 4.72". Interesting. Edelbrock considers the Victor Jr as a low profile intake.


Now the Victor Jr over the Air Gap? I'd say that if you'll never be less than 3000 rpm or so and spin well north of 7000 rpm, as a dedicated drag car might with a high stall converter or stick shift and an engine that matches, then you might benefit from the open plenum. If power and drivability at lower rpms is of any concern, then the dual plane is the way to go.


TKO Air Filter


GlassTek 2" Cowl Hood


.

TheZaZ

the glasstek 2" hood is the exact one I want to get so that helps alot.

skinny z

The RPM Air Gap has the divider removed. It seems to be the "de facto standard" when it comes to small block chevy street builds.

skinny z

I saw that video a while back and I had a question then and still haven't found an answer.
What would the results be with the Air Gap and the spacer?
I can guess that some of the low speed torque will be lost and the usable RPM range extended but I'd like to see some dyno results. I couldn't find anything published.

Night rider327

iTrader: (13)

Same here skinny... That would be a good test to see. I looked too and never found any info on it. Your guess is about what I was thinking. I do think the avg. TQ would be higher, with a slight loss under 3500, but a pretty good HP gain above 5500.


TheZaZ... If the budget is there and having to buy anyway, I would do the air gap RPM and 1" open spacer.

If not that, then the next best IMHO would be milled wall RPM and 1" open spacer.