Q-jet on built engine...bad idea?

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Dec 21, 2003 | 09:28 PM

Timbo2

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From: Somewhere in Mo

Q-jet on built engine...bad idea?

I got a Qjet, (rebuilt by Holley) that I bought for my 71 ... it works great when I stuck in on my 73 Camaro.. (which is for sale by the way)... but after getting the new 350 bored 30 over with a slight cam and double hump heads, the vette seems to be starving for gas. Did I screw up putting the Qjet on that engine, or is there some trick to making it work well on a slight "built" engine?

thanks,
TIm

Dec 21, 2003 | 09:40 PM

Smokehouse69

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From: Semper ubi, sub ubi

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Re: Q-jet on built engine...bad idea? (Timbo2)

Holley rebuilt Q-jets are notorious for poor performance. Holley does some goofy schit to the Q-jet, but a well tuned Q-jet will perform great on a 350.
Our resident Q-jet expert "Lars" has tuned a bunch of Q-jets for people here on the forum and they are usually very happy with the results.
He can also reverse the damage done by Holley rebuilds.
Drop him an email at V8FastCars@msn.com
He also has a number of articles out on http://www.corvettefaq.com on tuning the Q-jet.

Dec 22, 2003 | 09:04 AM

Stewart's74

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From: Florham Park NJ Port Credit Ontario

Re: Q-jet on built engine...bad idea? (Smokehouse69)

Lars re-built my Q-jet and it rocks :thumbs:

Dec 22, 2003 | 10:37 AM

Wrencher

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From: NorCal

Re: Q-jet on built engine...bad idea? (Timbo2)

I'm surprised Dep hasn't tuned in with his fix for a Q-jet: A large sledge hammer! :D

Hans

Dec 22, 2003 | 10:42 AM

Fevre

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From: Living in the Hartland

Re: Q-jet on built engine...bad idea? (Timbo2)

Sounds like a rejet/rerod is in order, if it was tuned for one eng of lower hp then it will prolly need some fine tuning when used on a higher hp eng.

Dec 22, 2003 | 04:36 PM

comp

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From: eville in

Re: Q-jet on built engine...bad idea? (Fevre)

his bound to jump on this one ,,, his just layin' back awile i bet. :lolg: :lolg:
on the Q-jet workin' take a look at the NHRA stocker & super stock cars
done correctly they will rock..... :party:

Dec 22, 2003 | 07:40 PM

hermit

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From: Oregon City , Oregon USA

Re: Q-jet on built engine...bad idea? (Timbo2)

Although it has been very popular to trash Q-jets I think that they are a very good alternative to the other carbs more commonly used. They have small primaries which helps keep low rpm velocity up. The seconaries are big enough to feed a healthy engine . And the metering system is very precise. The big trick is finding someone who knows how to work on them.

Dec 23, 2003 | 10:21 AM

Ganey

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From: CORVETTE 77 385 C.I. TEXAS

Re: Q-jet on built engine...bad idea? (Timbo2)

Since it was working good:
Make sure your primary piston is not stuck down. Engine off, in the float vent tube, you can use a small screwdriver to push piston down a little, should spring back up. If not, you can clean out w/ carb cleaner & hook it w/ a wire & pull it back up.
You may need to richen idle mixture & tune it.