tech question on Qjets

Dissident · 04-02-2016, 08:07 PM

I notice in some engine NHRA engine specs the Edelbrock carb replacement for the small venturi (1.093") QJet has the primary venturi sized to 1.108"......SO, can a guy open up the 1.093" unit .010" to .015" and be legal?

Thanks in advance,
Dissident

Mark Yacavone · 04-02-2016, 09:51 PM

I never noticed the spec difference but I think i know what you're talking about.
I saw some tech guys looking at a brand new Edelbrock one time.
It looked like the factory had taken a bearing scraper and removed the casting seam in the venturi.
They must have given the E-brock a little leeway.
I doubt you would get away with the same thing done to an OEM GM bowl.

Dwight Southerland · 04-03-2016, 08:59 AM

Page 133 in the Accepted Products publication. Read the footnote.

"1. * = All venturi dimensions include the .015" maximum allowance/tolerance for Rochester Qudrajets/Edelbrock replacements and .005" for all other carburetors."

The dimension is applicable to all Qjets.

Dissident · 04-05-2016, 12:47 AM

Thanks for the input. I am still waiting on getting an answer from NHRA that was posed to them at the PRI show. An NHRA guy said he would "get right back to me..."

That is why this forum is so important. And the communication is great.

Thanks again,
Dissident

04-02-2016, 08:07 PM	#1
Dissident Member Join Date: Jan 2016 Location: Colorado hills Posts: 123 Likes: 11 Liked 73 Times in 36 Posts	tech question on Qjets I notice in some engine NHRA engine specs the Edelbrock carb replacement for the small venturi (1.093") QJet has the primary venturi sized to 1.108"......SO, can a guy open up the 1.093" unit .010" to .015" and be legal? Thanks in advance, Dissident

04-02-2016, 09:51 PM	#2
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,742 Likes: 2,846 Liked 5,003 Times in 1,903 Posts	Re: tech question on Qjets I never noticed the spec difference but I think i know what you're talking about. I saw some tech guys looking at a brand new Edelbrock one time. It looked like the factory had taken a bearing scraper and removed the casting seam in the venturi. They must have given the E-brock a little leeway. I doubt you would get away with the same thing done to an OEM GM bowl. __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers

04-03-2016, 08:59 AM	#3
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 1,996 Likes: 63 Liked 756 Times in 189 Posts	Re: tech question on Qjets Page 133 in the Accepted Products publication. Read the footnote. "1. * = All venturi dimensions include the .015" maximum allowance/tolerance for Rochester Qudrajets/Edelbrock replacements and .005" for all other carburetors." The dimension is applicable to all Qjets. __________________

04-05-2016, 12:47 AM	#4
Dissident Member Join Date: Jan 2016 Location: Colorado hills Posts: 123 Likes: 11 Liked 73 Times in 36 Posts	Re: tech question on Qjets Thanks for the input. I am still waiting on getting an answer from NHRA that was posed to them at the PRI show. An NHRA guy said he would "get right back to me..." That is why this forum is so important. And the communication is great. Thanks again, Dissident