What would you do? Carb question
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 28,716
Likes: 4
From: Fort Mill, SC via NJ
What would you do? Carb question
Ok here's the scenario.
Recent engine rebuild.Talked into a Holley.
Asked by my performance shop what I was looking for and I said I want low end not too interested in top end.
So he said a 570 cfm Holley Avenger is better for low end.
Vette does run great.
The Q-Jet that was taken off was rebuilt recently by Lars.
Would you stay with the 570 Avenger or go back to a fresh Lars rebuilt 750 Q-jet?
[Modified by 69er, 6:06 PM 8/6/2001]
Recent engine rebuild.Talked into a Holley.
Asked by my performance shop what I was looking for and I said I want low end not too interested in top end.
So he said a 570 cfm Holley Avenger is better for low end.
Vette does run great.
The Q-Jet that was taken off was rebuilt recently by Lars.
Would you stay with the 570 Avenger or go back to a fresh Lars rebuilt 750 Q-jet?
[Modified by 69er, 6:06 PM 8/6/2001]
Melting Slicks
Joined: Dec 2000
Posts: 3,407
Likes: 2
From: Carmichael CA
Re: What would you do? Carb question (69er)
I've heard good things about lars work. The Q-jet has smaller primary venturies which would assist in better low end than the holley. IMHO the shop just wanted to make some cash on selling you another carb. Also, the Q-Jet was designed for your engine and thus would be the best "carb" for it. If you have the money then an EFI change over would be a better choice than a holley.
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 28,716
Likes: 4
From: Fort Mill, SC via NJ
Re: What would you do? Carb question (Rockn-Roll)
Yes the shop made more money on me but I think they want to do a rebuild with a fresh carb.So everything is new and runs better.
Performance shops love Holleys.
I was told Holleys in general are better for perfomance and Q-jets are better for driveability.
Ok I'll make the switch in a couple of weeks and see which one to me is better.
Performance shops love Holleys.
I was told Holleys in general are better for perfomance and Q-jets are better for driveability.
Ok I'll make the switch in a couple of weeks and see which one to me is better.
Racer
Joined: Mar 2001
Posts: 433
Likes: 0
Re: What would you do? Carb question (69er)
The Q-Jet is a very misunderstood component. Most people think of them as over-complicated and junk them when all that is needed is a rebuild and a clean. In stock form, the QJet flows 750cfm.
A few weeks ago, I decided to rebuild mine. I bought a kit from Corvette America and a really good book - Rochester Carbs by Doug Roe.
Armed with the book, the rebuild kit and a couple of cans of nasty carb cleaner, I removed the carb, broke it down into the three main sections, replaced the gaskets and other doo-dads, cleaned it and put it back. Total time, about 2 hours. It made a ton of difference. I fixed: Rough idle, hesitation from standing start, overall throttle response and probably gas mileage.
The book is $15, the rebuild kit $25. Spend the savings over a new carb on some other goodies.
Good luck.
A few weeks ago, I decided to rebuild mine. I bought a kit from Corvette America and a really good book - Rochester Carbs by Doug Roe.
Armed with the book, the rebuild kit and a couple of cans of nasty carb cleaner, I removed the carb, broke it down into the three main sections, replaced the gaskets and other doo-dads, cleaned it and put it back. Total time, about 2 hours. It made a ton of difference. I fixed: Rough idle, hesitation from standing start, overall throttle response and probably gas mileage.
The book is $15, the rebuild kit $25. Spend the savings over a new carb on some other goodies.
Good luck.
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Re: What would you do? Carb question (69er)
Joe,
I would go back to the Q-Jet. Mine has been just fine after a rebuild last winter. From idle to WOT it works very well. I understand that a Lars unit is the creme-de-la-creme
.
I would go back to the Q-Jet. Mine has been just fine after a rebuild last winter. From idle to WOT it works very well. I understand that a Lars unit is the creme-de-la-creme
.
Drifting
Joined: Nov 2000
Posts: 1,390
Likes: 39
From: North Brunswick NJ
Re: What would you do? Carb question (69er)
Joe,
Good seeing you over the weekend. What intake do you have on your engine , square bore or spread bore? If you have a square bore for the Holley you will need to change the intake or use a converter plate to make the Q-jet work. I dont like the converter plates as as perminent fix. If you can try both carbs and see choose the one that drives the best. If a converter plate is necessary I would choose the carb that does not need it. I dont think changing the intake would be worth the effort.
Ed
[Modified by ED DINAPOLI, 8:23 PM 8/6/2001]
Good seeing you over the weekend. What intake do you have on your engine , square bore or spread bore? If you have a square bore for the Holley you will need to change the intake or use a converter plate to make the Q-jet work. I dont like the converter plates as as perminent fix. If you can try both carbs and see choose the one that drives the best. If a converter plate is necessary I would choose the carb that does not need it. I dont think changing the intake would be worth the effort.
Ed
[Modified by ED DINAPOLI, 8:23 PM 8/6/2001]
Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Re: What would you do? Carb question (69er)
69er,
I would go with the larger Q Jet rebuilt by someone who knows what they are doing over the small Holley Avenger. For me, the main advantage Holley's have over everything else but Webbers or DelOtros is the center pivol bowls. They are much better for high G cornering. I don't think the Avengers have center pivot bowls. Keep the Q Jet is my 2 cents.
Chuck
I would go with the larger Q Jet rebuilt by someone who knows what they are doing over the small Holley Avenger. For me, the main advantage Holley's have over everything else but Webbers or DelOtros is the center pivol bowls. They are much better for high G cornering. I don't think the Avengers have center pivot bowls. Keep the Q Jet is my 2 cents.
Chuck
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Team Owner
Joined: Jun 2001
Posts: 43,136
Likes: 155
From: Thomson Georgia
Re: What would you do? Carb question (69er)
I have a 600 Edelbrock and a Q-Jet as well.. I get better mileage and drivability with the edelbrock but a little more power with the q-jet...Why not run the holley and keep the q-jet so u have the original carb if u do sell it...U can always switch them out..... :cheers:
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 28,716
Likes: 4
From: Fort Mill, SC via NJ
Re: What would you do? Carb question (Alwyn678)
Alwyn678
Actually the q-jet is not the original.
I'm going to go with the crowd and try out Lars' rebuilt q-jet.
If it works out I'll sell the Holley.
Ed
I have a Edelbrock Performer which had the q-jet on before the engine rebuild.
Should work out.
Q-Jet will be on soon.
Once again
Thanks guys.
Actually the q-jet is not the original.
I'm going to go with the crowd and try out Lars' rebuilt q-jet.
If it works out I'll sell the Holley.
Ed
I have a Edelbrock Performer which had the q-jet on before the engine rebuild.
Should work out.
Q-Jet will be on soon.
Once again
Thanks guys.