Rochester Rebuild? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Anchorism · 04-23-2014, 12:24 PM

So the 454 that I'm currently rebuilding is getting close to being complete. The last part that I need to decide what to do with is the carburetor. It had the original Rochester Q-jet. What I am wondering is how good are the original Q-jets? My cousin is saying that they aren't that great and I should look for something better. The problem with that is im on a tight budget. I think a $35 rebuild kit is worth giving it a shot. He stated that the throttle shaft tends to wear out allowing a vacuum leak. So is it worth attempting the rebuild or should I start searching for something different?

bnoon · 04-23-2014, 12:44 PM

If the throttle shafts are worn, the best solution is to replace the bushings. http://quadrajetparts.com/rochester-...-c-128_34.html

If you don't know what you are doing, do a Google search for Mountain Man Fuel Systems (seller on Ebay). I've used two of his rebuilds and they are a work of art. He does the epoxy fill fix (for anti-drain back issues), replaces worn parts, etc. and does it on an exchange basis for no down time. Well worth it if you don't have the time or knowledge to handle these things yourself.

**Corts60** · 04-23-2014, 12:48 PM

Oh this thread is going to explode here in a bit....

This is an age old argument. There are many that love the Q-Jet, and probably many more that hate it. I am on the love side of the fence. It is an outstanding carburetor when PROPERLY rebuilt. It is, however, a little more complicated than some of it's aftermarket competitors. If you've never rebuilt a carb before, I would recommended either getting someone to help you or buying a good how to book on the q-jet specifically.

You could spend $35 on a rebuild out and about $20 on a good book and end up with a great carb. If you don't think you're ready to tackle it, spend the $200 for a new carb of your choice and call it a day.

If it were me, I would rebuild it. No carb makes that wonderful throaty sound at WOT like a Q-jet spread bore. Just my .02.

rich weyand · 04-23-2014, 01:39 PM

Quote:

Originally Posted by Corts60

Oh this thread is going to explode here in a bit....

This is an age old argument. There are many that love the Q-Jet, and probably many more that hate it. I am on the love side of the fence. It is an outstanding carburetor when PROPERLY rebuilt. It is, however, a little more complicated than some of it's aftermarket competitors. If you've never rebuilt a carb before, I would recommended either getting someone to help you or buying a good how to book on the q-jet specifically.

You could spend $35 on a rebuild out and about $20 on a good book and end up with a great carb. If you don't think you're ready to tackle it, spend the $200 for a new carb of your choice and call it a day.

If it were me, I would rebuild it. No carb makes that wonderful throaty sound at WOT like a Q-jet spread bore. Just my .02.

Agreed in all respects.

Rebuild it with the Cliff Ruggles book. You don't have to worry about tuning all the air bleeds and such if it is going back on the same engine.

How to Rebuild and Modify Rochester Quadrajet...

If you don't want to rebuild it, and are going to buy a rebuilt carb, get one from Sean Murphy. He will ask you a bunch of questions so he can send you one with all the air bleeds and such set up properly.
http://www.smicarburetor.com/

Anchorism · 04-23-2014, 01:53 PM

The nice thing is my cousin is a great carb tuner.... he knows what he's doing. He just feels that the old Q-jet from 1979 might be quite worn out!

bnoon · 04-23-2014, 09:38 PM

Quote:

Originally Posted by Anchorism

The nice thing is my cousin is a great carb tuner.... he knows what he's doing. He just feels that the old Q-jet from 1979 might be quite worn out!

Worn out, but totally rebuildable. Everything that your quadrajet needs is available in the aftermarket.

mrolds88 · 04-23-2014, 10:49 PM

The worst thing about the 79 Qjet would be worn shaft bushings. The later "electronic" units I do not care for at all. But those earlier ones are good to go. At least you can tune them. I would go with the rebuild on the carb you have.

motornut · 04-24-2014, 11:04 PM

going to rebuild my 79s QJet,swapping two to four is the plan
fed up with the 78s holley

04-23-2014, 12:24 PM	#1
Anchorism Registered User Join Date: Mar 2013 Location: Dublin Ohio Posts: 203	Rochester Rebuild? So the 454 that I'm currently rebuilding is getting close to being complete. The last part that I need to decide what to do with is the carburetor. It had the original Rochester Q-jet. What I am wondering is how good are the original Q-jets? My cousin is saying that they aren't that great and I should look for something better. The problem with that is im on a tight budget. I think a $35 rebuild kit is worth giving it a shot. He stated that the throttle shaft tends to wear out allowing a vacuum leak. So is it worth attempting the rebuild or should I start searching for something different?

04-23-2014, 12:44 PM	#2
bnoon Registered User Join Date: Jul 2012 Location: Des Moines IA Posts: 1,250	Re: Rochester Rebuild? If the throttle shafts are worn, the best solution is to replace the bushings. http://quadrajetparts.com/rochester-...-c-128_34.html If you don't know what you are doing, do a Google search for Mountain Man Fuel Systems (seller on Ebay). I've used two of his rebuilds and they are a work of art. He does the epoxy fill fix (for anti-drain back issues), replaces worn parts, etc. and does it on an exchange basis for no down time. Well worth it if you don't have the time or knowledge to handle these things yourself. __________________ - 1981 Sierra 454, NV4500 swap - 2006 Z06, 25k miles - 1973 Nova - Project CarNova Virus on Youtube

04-23-2014, 12:48 PM	#3
Corts60 Just here to tinker Join Date: Jun 2008 Location: Holland, MI Posts: 3,697	Re: Rochester Rebuild? Oh this thread is going to explode here in a bit.... This is an age old argument. There are many that love the Q-Jet, and probably many more that hate it. I am on the love side of the fence. It is an outstanding carburetor when PROPERLY rebuilt. It is, however, a little more complicated than some of it's aftermarket competitors. If you've never rebuilt a carb before, I would recommended either getting someone to help you or buying a good how to book on the q-jet specifically. You could spend $35 on a rebuild out and about $20 on a good book and end up with a great carb. If you don't think you're ready to tackle it, spend the $200 for a new carb of your choice and call it a day. If it were me, I would rebuild it. No carb makes that wonderful throaty sound at WOT like a Q-jet spread bore. Just my .02. __________________ 78 C10 SWB Diesel #1 (wrecked)http://67-72chevytrucks.com/vboard/s...1978+silverado 78 C10 SWB Diesel #2 (sold)http://67-72chevytrucks.com/vboard/s...d.php?t=650751 60 GMC Suburban (sold)http://67-72chevytrucks.com/vboard/s...d.php?t=445526 60 GMC 1000 (sold)http://67-72chevytrucks.com/vboard/showthread.php?t=298235 67 GMC 1500 (sold) http://67-72chevytrucks.com/vboard/s...d.php?t=803695 73 Chevy C20(Daily)http://67-72chevytrucks.com/vboard/s...d.php?t=852767 86 Suburban(summer unit) http://67-72chevytrucks.com/vboard/s...d.php?t=810697 88 Suburban 4x4(sold)

04-23-2014, 01:53 PM	#5
Anchorism Registered User Join Date: Mar 2013 Location: Dublin Ohio Posts: 203	Re: Rochester Rebuild? The nice thing is my cousin is a great carb tuner.... he knows what he's doing. He just feels that the old Q-jet from 1979 might be quite worn out!

04-23-2014, 10:49 PM	#7
mrolds88 Registered User Join Date: Jul 2011 Location: WV Posts: 946	Re: Rochester Rebuild? The worst thing about the 79 Qjet would be worn shaft bushings. The later "electronic" units I do not care for at all. But those earlier ones are good to go. At least you can tune them. I would go with the rebuild on the carb you have. __________________ 72 GMC C2500 402/Th400 first truck (still have) 77 GMC C3500 CC dually Sold 70 C50 dump truck "Rusty" 87 K10 Suburban Sold 93 K2500 xcab 6.5TD 96 GMC K2500 Suburban 6.5 TD

04-24-2014, 11:04 PM	#8
motornut 78K & 79C Jimmys Join Date: Nov 2009 Location: Ottawa Ont CANADA Posts: 7,901	Re: Rochester Rebuild? going to rebuild my 79s QJet,swapping two to four is the plan fed up with the 78s holley __________________ John 1978 GMCJimmy4X4-350/203 1979 GMCJimmy4X2-305/350



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