RPM Air Gap question
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Pro
Joined: Apr 2009
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RPM Air Gap question
Hello all,
I've got a picture of an RPM Air Gap I'm interested in purchasing. The picture is of the port where the runners meet the head. There are holes in the upper part of the runners and they looked tapped. Is this the way they come from the factory? It seems like fuel/airflow would be disturbed. Anybody ever see these when they installed their RPM Air Gap?
Thanks for the help.
I've got a picture of an RPM Air Gap I'm interested in purchasing. The picture is of the port where the runners meet the head. There are holes in the upper part of the runners and they looked tapped. Is this the way they come from the factory? It seems like fuel/airflow would be disturbed. Anybody ever see these when they installed their RPM Air Gap?
Thanks for the help.
Terrorizing Orange Cones
Joined: Oct 2007
Posts: 2,572
Likes: 17
From: Northern CO
Brando1118, the Air-Gap is usually not offered with those bosses tapped. Here's an image of mine:
I don't imagine airflow is disrupted much, if at all without something protruding from the hole. That is also subjective and open for discussion.
I imagine Edelbrock molds them if you choose to tap for fuel injection or NOS nozzles. If the one you are reviewing has them opened, I'd expect they're tapped for pipe threads therefore, some appropriate plugs will seal any vacuum leaks. If not pipe threaded, you may wish to continue surfing as any leaks would be troublesome, especially on a C3 with vacuum-dependent sub-systems.
Hope this helps.
BTW: the ports in your image look pretty rough and not from a manufacturing viewpoint. I wonder if Bubba was attempting to recreate a magazine article he read?
I don't imagine airflow is disrupted much, if at all without something protruding from the hole. That is also subjective and open for discussion.
I imagine Edelbrock molds them if you choose to tap for fuel injection or NOS nozzles. If the one you are reviewing has them opened, I'd expect they're tapped for pipe threads therefore, some appropriate plugs will seal any vacuum leaks. If not pipe threaded, you may wish to continue surfing as any leaks would be troublesome, especially on a C3 with vacuum-dependent sub-systems.
Hope this helps.
BTW: the ports in your image look pretty rough and not from a manufacturing viewpoint. I wonder if Bubba was attempting to recreate a magazine article he read?
Last edited by Dustup7T2; Mar 2, 2010 at 11:39 AM.
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Thanks Dustup7T2,
Yeah, the port clean up job does have a *bubba* like touch to it doesn't it? I don't think the holes go all the way through. It would be impossible to tap those holes without having access from the top, so that is why I wonder if it came from the factory like this.Here is the top of the intake:
Yeah, the port clean up job does have a *bubba* like touch to it doesn't it? I don't think the holes go all the way through. It would be impossible to tap those holes without having access from the top, so that is why I wonder if it came from the factory like this.Here is the top of the intake:
Tech Contributor
Joined: Aug 1999
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From: At my Bar drinking and wrenching in Lafayette Colorado
The ports have been drilled and tapped for Nitrous injectors and then welded closed from the outside - notice how your nitrous bosses have a "rounded" appearance. After welding, the manifold was bead blasted to give it a uniform appearance. If too much heat was put into it during welding, the manifold flange can be twisted.
Lars
Lars
Safety Car
Joined: Mar 2009
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From: Oakland California
The ports have been drilled and tapped for Nitrous injectors and then welded closed from the outside - notice how your nitrous bosses have a "rounded" appearance. After welding, the manifold was bead blasted to give it a uniform appearance. If too much heat was put into it during welding, the manifold flange can be twisted.
Lars
Lars
