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-   -   Performer RPM Air Gap fits under 1970 hood (https://www.corvetteforum.com/forums/c3-tech-performance/4230561-performer-rpm-air-gap-fits-under-1970-hood.html)

Crimson Thunder 01-11-2019 10:12 AM

Performer RPM Air Gap fits under 1970 hood
 
I recently got a good deal on a brand new Performer RPM air gap intake. Edelbrock states in their catalog that will not fit under Corvette hood. Well, with the factory 1970 drop base air cleaner and small block flat hood it fits with a half inch to spare.

The picture I took is with my cheap borescope camera taped to the metal fan shroud(it needed more light). I also used wadded up aluminum foil to check the clearance.
https://cimg2.ibsrv.net/gimg/www.cor...61f9d5f2e.jpeg
https://cimg1.ibsrv.net/gimg/www.cor...3da0fbf5a4.jpg

resdoggie 01-11-2019 11:48 AM

How much space is there between the carb flange and the lid?

Crimson Thunder 01-11-2019 01:24 PM

I have a Holley HP carb without a choke tower. There is little over a half inch from the vent tube to the bottom of the air cleaner. I used Jenga blocks (exactly 3 inches) in place of the air cleaner to get the measurements.

forman 01-11-2019 06:31 PM

wont fit with a big block ,,, with the air horns cut off it just makes it.. lol

HeadsU.P. 01-11-2019 06:51 PM

According to a discussion I had with Holley tech guy, he said I should have 3/4" clearance between lid a fuel bowl vent. I do not. A little less.
I have 1+1/2" drop base, 3" filter on a 4150.

However, after some exhausting searches I did find custom made brass bowl vents for Holley. They were $35 a pair, OUCH! Instead of the vent hole on top of the brass tube, the hole is on the side. That prevents the turbulence from siphoning fuel out of the bowls. I have yet to install them and plan on having a machinist tweak them on a lathe this winter.

MelWff 01-11-2019 07:16 PM

the number I have often heard is 3/8" read post #9 in the thread
https://www.corvetteforum.com/forums...ent-tubes.html

cv67 01-11-2019 07:25 PM

Probably a disclaimer, who knows what has been done to these cars over the years. Good to know youre not stuck with a puky small intake though.

HeadsU.P. 01-11-2019 08:00 PM


Originally Posted by MelWff (Post 1598667658)
the number I have often heard is 3/8" read post #9 in the thread
https://www.corvetteforum.com/forums...ent-tubes.html

See your post 19.
I would bet that if the Holley slosh whistles were installed in the bowls, that would change the minimum to something in between 3/8 and 3/4.

ajrothm 01-11-2019 10:25 PM

Good post! That answers the question for a lot of people. Now SB guys can run a decent intake and not be stuck with Performers, Torker IIs or other junk intakes, and still be able to run the proper size air filter. Nice job...

OldCarBum 01-12-2019 02:42 AM


Originally Posted by HeadsU.P. (Post 1598667513)
According to a discussion I had with Holley tech guy, he said I should have 3/4" clearance between lid a fuel bowl vent. I do not. A little less.
I have 1+1/2" drop base, 3" filter on a 4150.

However, after some exhausting searches I did find custom made brass bowl vents for Holley. They were $35 a pair, OUCH! Instead of the vent hole on top of the brass tube, the hole is on the side. That prevents the turbulence from siphoning fuel out of the bowls. I have yet to install them and plan on having a machinist tweak them on a lathe this winter.

You might want to look at the vent tubes for a marine Holley. The tubes are shorter and actually bend 180 degrees so the top of the tube faces downward so any fuel in the vent tubes dumps back into the carb just above the quarters.

cv67 01-12-2019 02:50 AM


Originally Posted by ajrothm (Post 1598668873)
Good post! That answers the question for a lot of people. Now SB guys can run a decent intake and not be stuck with Performers, Torker IIs or other junk intakes, and still be able to run the proper size air filter. Nice job...

but what kind of oil is best? lol

terrys6t8roadster 01-12-2019 06:05 AM


Originally Posted by Crimson Thunder (Post 1598663830)
I recently got a good deal on a brand new Performer RPM air gap intake. Edelbrock states in their catalog that will not fit under Corvette hood. Well, with the factory 1970 drop base air cleaner and small block flat hood it fits with a half inch to spare.

The picture I took is with my cheap borescope camera taped to the metal fan shroud(it needed more light). I also used wadded up aluminum foil to check the clearance.
https://cimg2.ibsrv.net/gimg/www.cor...61f9d5f2e.jpeg
https://cimg1.ibsrv.net/gimg/www.cor...3da0fbf5a4.jpg

Nice looking engine compartment. Which carb are you using?

HeadsU.P. 01-12-2019 07:46 AM


Originally Posted by OldCarBum (Post 1598669702)


You might want to look at the vent tubes for a marine Holley. The tubes are shorter and actually bend 180 degrees so the top of the tube faces downward so any fuel in the vent tubes dumps back into the carb just above the quarters.

Yes, I saw those. Pretty clever but not really what I had in mind.

Crimson Thunder 01-12-2019 12:25 PM


Originally Posted by terrys6t8roadster (Post 1598669847)
Nice looking engine compartment. Which carb are you using?

Holley HP 650

jb78L-82 01-12-2019 03:16 PM

Good to know! Thanks.

Can you take the air cleaner off and take a photo with the Holley sitting on the RPM air gap intake on the engine?

Little Mouse 01-13-2019 12:37 AM

Contend with
 
Edelbrock has to say the rpm manifold will not fit under stock hood to cover its behind. Because as sure as if they said it would many folks would buy the taller then the original l/48 rpm manifold then stick the factory air cleaner on top of it that was designed to work with the factories lower hight manifold.then they would be faced with phone call complaints to maybe even law suite as to why there was no warning it would not fit. This sounds crazy but true. A woman bought a new winnebego driving it down the road she set the cruze control on, got up went and started making herself a samdwich well of course the winnebego ran off the road. She sued them because there was nothing in the owners manual saying you could not do that and won the case and a money reward from the court.

Crimson Thunder 01-13-2019 09:34 AM


Originally Posted by jb78L-82 (Post 1598672456)
Good to know! Thanks.

Can you take the air cleaner off and take a photo with the Holley sitting on the RPM air gap intake on the engine?

I really need to find a way to reinstall my 1/4 spacer so I can reinstall my billet water neck and get rid of that ugly Mr Gasket one and give the fuel line more clearance to the heater hose nipple.
https://cimg2.ibsrv.net/gimg/www.cor...eaecae3432.jpg

resdoggie 01-13-2019 09:46 AM

Get an air filter 1/4" less in height.

jb78L-82 01-13-2019 10:04 AM


Originally Posted by Crimson Thunder (Post 1598676270)
I really need to find a way to reinstall my 1/4 spacer so I can reinstall my billet water neck and get rid of that ugly Mr Gasket one and give the fuel line more clearance to the heater hose nipple.
https://cimg2.ibsrv.net/gimg/www.cor...eaecae3432.jpg


Very Nice...Thank You


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