Is an air gap manifold needed?
#1
Thread Starter
Registered

Joined: Oct 2013
Posts: 2,888
Likes: 148
From: SF Bay Area
My carbed 502 should be about ~550ish hp and currently has a Performer RPM non-air gapped intake. I see that Edelbrock offers an air gapped version and I have plenty of room under the hatch. Is this something worth switching out when I swap cams?
Also, I read that the RPM manifolds tend to not respond real well to a carb spacer and was wondering if anyone here has any experience with that.
Tia.
Also, I read that the RPM manifolds tend to not respond real well to a carb spacer and was wondering if anyone here has any experience with that.
Tia.
#3
Thread Starter
Registered

Joined: Oct 2013
Posts: 2,888
Likes: 148
From: SF Bay Area
The 550 is an optimistic number on the crate motor of 500, and maybe the EFI525 cam will get me higher. Realistically, my guess now currently is about 450 at the flywheel at best. Should I be looking at a single plane instead? Performer RPM heads Oval port 9.6:1 static.
#4
Registered

Joined: Nov 2004
Posts: 14,068
Likes: 3,667
From: On A Dirt Floor
The Vic jr has been out powering (on the water) both the RPM intakes on approx 450hp 454's and higher.
Same reason open spacers on the dual planes on same motors will make more power (on the water) but people with Widebands have reported this really screws up their already screwed up bank to bank A/F ratio.
Same reason open spacers on the dual planes on same motors will make more power (on the water) but people with Widebands have reported this really screws up their already screwed up bank to bank A/F ratio.
#5
Thread Starter
Registered

Joined: Oct 2013
Posts: 2,888
Likes: 148
From: SF Bay Area
The Vic jr has been out powering (on the water) both the RPM intakes on approx 450hp 454's and higher.
Same reason open spacers on the dual planes on same motors will make more power (on the water) but people with Widebands have reported this really screws up their already screwed up bank to bank A/F ratio.

Same reason open spacers on the dual planes on same motors will make more power (on the water) but people with Widebands have reported this really screws up their already screwed up bank to bank A/F ratio.

#8
Registered
Joined: Dec 2010
Posts: 783
Likes: 22
From: Chestertown, MD
I'm trying my Air gap next season. That's a 600hp 454. Used to run a single plane Team G, If I don't like it it's easy to go back. But I bet throttle would be a little easier in the docs vs. a single plane.
#9
Thread Starter
Registered

Joined: Oct 2013
Posts: 2,888
Likes: 148
From: SF Bay Area
With a bit of googling it seems that milling down the center divider on the dual plane giving it a touch more top end.
#10
Registered

Joined: Mar 2004
Posts: 2,696
Likes: 93
From: Pa
Dynoed a 468 2 weeks ago, old single plane and air gap made the same HP at the same 6300 RPM. The dual plane made 45lbs more torque at 3000 rpm, was ove 500 from 3000 to 4300, single plane broke 500 from 4100 to 4300.


