Q-jet rebuild question
Thread Starter
Le Mans Master
Joined: Nov 2000
Posts: 6,266
Likes: 156
From: Galloway Twp. NJ
Cruise-In VII Veteran
Q-jet rebuild question
When a carburator is restored, how is the body of the carb cleaned and made to look like new?
is it dipped is some sort of chemical cleaner or bead blasted?
(and I'm not just talking about cleaning off some varnish and grease.)
is it dipped is some sort of chemical cleaner or bead blasted?
(and I'm not just talking about cleaning off some varnish and grease.)
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
It depends on what carbs you're looking at. A lot are just spray painted. There are paint kits that will give you the correct color, but the look is obviously painted. You can do the paint yourself if you're not too fussy about the look.
Then there's the expensive way which is to have the carb replated. This isn't something you can't do yourself and requires sending it out to a carb restorer.
Then there's the expensive way which is to have the carb replated. This isn't something you can't do yourself and requires sending it out to a carb restorer.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Zinc Chromate.
Originally Posted by RPOZ4Z
When a carburator is restored, how is the body of the carb cleaned and made to look like new?
is it dipped is some sort of chemical cleaner or bead blasted?
(and I'm not just talking about cleaning off some varnish and grease.)
is it dipped is some sort of chemical cleaner or bead blasted?
(and I'm not just talking about cleaning off some varnish and grease.)
Do u really need a "like new restoration" of the carb? Is it even numbers matching for the car? Is the engine even a numbers match for the car? Or do u just want to adjust it for better operation? Problems as is?
The Q-jet is more complicated/difficult than a Holley type carb and my recommendation is to get Roe's book and tune it up as best as possible just to get familiar with it before u tear it apart.
Good luck and hopes this helps. If you need advice on any particular problem just post. The archives have plenty of good information from others that have travel that road also.
cardo0
Thread Starter
Le Mans Master
Joined: Nov 2000
Posts: 6,266
Likes: 156
From: Galloway Twp. NJ
Cruise-In VII Veteran
Yes, it's a numbers matching engine.
Yes, it's the original carb for the car. (date code is correct.)
I have rebuilt a quadrajet before, and I'm no stranger to rebuilding a carb.
the engine hasn't been run in 20 years, the carb has surface rust on the choke plate and on the vaccum secondary plates, and is very "weathered" looking.
that's no big deal, I can bead blast the plates.
but, I'm curious as to how they get the carb to look new.
is the body of the carb bead blasted?
or just soaked in cleaner?
and is it painted that gold color instead of re-plated.
Thanks
Yes, it's the original carb for the car. (date code is correct.)
I have rebuilt a quadrajet before, and I'm no stranger to rebuilding a carb.
the engine hasn't been run in 20 years, the carb has surface rust on the choke plate and on the vaccum secondary plates, and is very "weathered" looking.
that's no big deal, I can bead blast the plates.
but, I'm curious as to how they get the carb to look new.
is the body of the carb bead blasted?
or just soaked in cleaner?
and is it painted that gold color instead of re-plated.
Thanks
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
If you bead blast the cast parts, you will put a texture into the surface that will never look right again. The commercial builders do this, and their carbs all look like garbage - they destroy the carb.
You can dip the carb in acid, such as the metal prep acid sold by PPG for etching metal prior to conversion coating. If you scrub the carb with a soft bristle brush in the acid, you can remove all the corrosion. You can then dip the carb in PPGs Alodine conversion coating. This is an aluminum conversion coating that will put the brownish-goldish color back on the carb - the exact color depends on the carb and how it reacts with the conversion coating.
Painting the carb with the "carb paint" process makes it look awful. Just my opinion. And if you ever rebuild the carb again, the paint will come off and plug up every oriface in the carb..
You can dip the carb in acid, such as the metal prep acid sold by PPG for etching metal prior to conversion coating. If you scrub the carb with a soft bristle brush in the acid, you can remove all the corrosion. You can then dip the carb in PPGs Alodine conversion coating. This is an aluminum conversion coating that will put the brownish-goldish color back on the carb - the exact color depends on the carb and how it reacts with the conversion coating.
Painting the carb with the "carb paint" process makes it look awful. Just my opinion. And if you ever rebuild the carb again, the paint will come off and plug up every oriface in the carb..
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Thx lars.
I think the rebuild u did on my carb looks great lars and couldn't recall how u finished it. Man i didn't know alodine would do the job. Great news as i have stack of carbs that are gonn'a need it. I need to copy/save this post and thx for chimming in.
IMHO recoating the carb is not normally needed unless the coating is removed/deteriorated from the internals of carb - that really needs the protection. And powder coating the outside of the carb has it place too but best left for experienced pros.
cardo0
IMHO recoating the carb is not normally needed unless the coating is removed/deteriorated from the internals of carb - that really needs the protection. And powder coating the outside of the carb has it place too but best left for experienced pros.
cardo0
Melting Slicks
Joined: Mar 2006
Posts: 3,342
Likes: 7
From: Connecticut
Originally Posted by lars
If you bead blast the cast parts, you will put a texture into the surface that will never look right again. The commercial builders do this, and their carbs all look like garbage - they destroy the carb.
.
.
With a good core and proper glass beading and the proper coating there is no texture,
I have one and I have seen 30 year old OEM Qj's still in the box...
Looks Identica other than a possible difference in color.
And before anybody bashes me for disagreeing with Lars I can say I have a ton of respect for his work and talent and I look forward to any of his posts which I usually copy and put in a folder named Lars.
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
Thread Starter
Le Mans Master
Joined: Nov 2000
Posts: 6,266
Likes: 156
From: Galloway Twp. NJ
Cruise-In VII Veteran
so glass beading would work if care was taken......
I'll look into the acid dipping and alodine conversion coating, sounds like a good way to go.
I just didn't know if glass beading a carb was an acceptable thing to do, I didn't want to take the chance of getting glass bead into the passages of the carb and ruin it.
Thanks everyone for the info!
I'll look into the acid dipping and alodine conversion coating, sounds like a good way to go.
I just didn't know if glass beading a carb was an acceptable thing to do, I didn't want to take the chance of getting glass bead into the passages of the carb and ruin it.
Thanks everyone for the info!