Carb Questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

lofat · 03-11-2004, 07:52 PM

Couple quick questions: Did our trucks typically come with Q-Jets stock? Also I have heard that there are rebuild kits pretty cheap, and that they are pretty easy to do. I am a reasonably smart, fairly mechanically inclined (once I do something I am usually able to do it again), but I personally have never done any carb work before. Does it make sense for me to attempt this my self? Also does any one recommend a specific kit over another?

I am assuming that this is the original carb, that came with the truck, and I am unsure of when it was last adjusted/serviced, so I figured that before tuning it all up I would do a rebuild first.

Thanks in advance

Scott

8t5Silverado · 03-11-2004, 08:06 PM

Yes,

Q-Jets were stock on our trucks.

As for simple to work on, I don't know for sure. I need to rebuild mine, but I think I will wait until I have a "second" carb to rebuild, so I can keep my truck running (just in case).

I have done a Holley 4bbl and a tri-power off of a 66 GTO, so I can't see a Q-Jet being too bad.

lofat · 03-12-2004, 12:36 PM

right on - thanks.

anyone suggest a rebuild kit?

**swervin ervin** · 03-12-2004, 01:03 PM

I have used kits from Edelbrock and kits from Advance Auto Parts. Only difference I could see is the price. One was $55.00 and the other was $25.00. For sure there was nothing different to warrant the money difference except maybe the name.

I would go to Advance. Get number off the carb on the pad right behind the linkage.

Destructo · 03-12-2004, 01:08 PM

I rebuilt my own, didn't have any problems and it seems to run fine, gets about 16 MPG in a shortbed 4" lifted 4x4 with 33's and 3.42 gears, so it must be doing pretty good. Also passes emissions like a fuel injected car. That must be why they call them redneck fuel injection

I love my Q-Jet, had a holley on this truck before and it wasn't any fun at all, always tinkering with it to keep it running good and plus it melted my cats because the floats settled some. The only thing you really need to pay attention to is the play in the shafts, if theres too much you may need a bushing kit for it. And the only difficult part which really isn't that hard is adjusting the float right, it needs to be at 11/32nds and the kit should provide a paper ruller for you to use. That the only thing you really need to change when you rebuild it. Other wise your basically replacing gaskets and seals for the accelerator pump. It was very easy to do in my own opinion. They also provide you with instructions, or you can go by the haynes manual if you want, they both have break downs of the carb so you can see all the parts.

lofat · 03-12-2004, 01:40 PM

sweet!
Thanks for the info guys! btw - 16 mpg... wow. i would love that. i think i am pulling 11 mpg now.

Destructo · 03-12-2004, 01:44 PM

I was amazed I get that kinda mileage too! My speedo is a little bit off but pretty much right, maybe a couple mph off at 65 mph. So that will affect it some but not much. It was actually 16.5 but I rounded off some for compensate for the speedo being off a little. I have a 700r4 but only use third gear on the highway because my gearing it too low (3.42,s with 33's) and only turn about 2200 on the highway. Going to go to 4.56 gears and should turn about the same but in 4th gear. That will probably help out the mileage some having it able to use less power to turn the wheels but still cruise at less than 2500 rpm.

And having that carb tuned and in perfect working order and a good strong running motor will do wonders for gas mileage.

MylilBowTie · 03-12-2004, 02:27 PM

If you want to tackle it. Get some carburetor cleaner dip, a book Rochester Carburetors: Tune, Rebuild or Modify by Doug Roe and a little bit of time. Air compressor with a rubber tip blow off tool would be nice or a can of compressed air like to clean computer dust out of the cpu. To get the residual carburetor cleaner out of the parts and to clear the passage ways. I haven't rebuilt a q-jet yet but its on the todo list. I have rebuilt 1406-1407 those are pretty easy unless the linkage (spring setup) for the secondaries comes off.

Here is the link, looks to be okay I don't think any modifications where done. Like using sealant to stop the internal leak. Cant remember what its called right now.
http://www.4wheelnoffroad.com/qjet.html

ocbaud · 03-12-2004, 02:42 PM

if i were to decide on using my stock qjet off my 305, on my new engine, how would i need to build it up to perform great?

lofat · 03-12-2004, 07:26 PM

Quote:

Originally posted by MylilBowTie

http://www.4wheelnoffroad.com/qjet.html

btw - that is a great link.

NeCrOmAnCeR · 03-12-2004, 08:20 PM

Here are a few q-jet performance mod links for you ocbaud

http://www.geocities.com/gtopercy/Pi...rajetTech.html

http://www.buickpartsdirectory.com/Q...ning_Paper.doc

I have found these to cover most mods I have done to a q-jet.

03-11-2004, 07:52 PM	#1
lofat Rollin' Member Join Date: May 2003 Location: Hayward, California Posts: 240	Carb Questions Couple quick questions: Did our trucks typically come with Q-Jets stock? Also I have heard that there are rebuild kits pretty cheap, and that they are pretty easy to do. I am a reasonably smart, fairly mechanically inclined (once I do something I am usually able to do it again), but I personally have never done any carb work before. Does it make sense for me to attempt this my self? Also does any one recommend a specific kit over another? I am assuming that this is the original carb, that came with the truck, and I am unsure of when it was last adjusted/serviced, so I figured that before tuning it all up I would do a rebuild first. Thanks in advance Scott __________________ :: 1977 C10 cheyenne :: :: 1973 new yorker brougham :: for sale - $1,500 lofat productions

03-11-2004, 08:06 PM	#2
8t5Silverado Mudslides 'r my specialty Join Date: Dec 2003 Location: STL Posts: 1,106	Yes, Q-Jets were stock on our trucks. As for simple to work on, I don't know for sure. I need to rebuild mine, but I think I will wait until I have a "second" carb to rebuild, so I can keep my truck running (just in case). I have done a Holley 4bbl and a tri-power off of a 66 GTO, so I can't see a Q-Jet being too bad. __________________ Always on the lookout for old cars and parts...(20s, 30s, 40s, 50s, 60s, etc.) http://www.cardomain.com/memberpage/500339

03-12-2004, 12:36 PM	#3
lofat Rollin' Member Join Date: May 2003 Location: Hayward, California Posts: 240	right on - thanks. anyone suggest a rebuild kit? __________________ :: 1977 C10 cheyenne :: :: 1973 new yorker brougham :: for sale - $1,500 lofat productions

03-12-2004, 01:03 PM	#4
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	I have used kits from Edelbrock and kits from Advance Auto Parts. Only difference I could see is the price. One was $55.00 and the other was $25.00. For sure there was nothing different to warrant the money difference except maybe the name. I would go to Advance. Get number off the carb on the pad right behind the linkage. __________________ Mike 1985 Chevy C-10

03-12-2004, 01:08 PM	#5
Destructo Registered User Join Date: Sep 2003 Location: Lewisville, NC Posts: 1,836	I rebuilt my own, didn't have any problems and it seems to run fine, gets about 16 MPG in a shortbed 4" lifted 4x4 with 33's and 3.42 gears, so it must be doing pretty good. Also passes emissions like a fuel injected car. That must be why they call them redneck fuel injection I love my Q-Jet, had a holley on this truck before and it wasn't any fun at all, always tinkering with it to keep it running good and plus it melted my cats because the floats settled some. The only thing you really need to pay attention to is the play in the shafts, if theres too much you may need a bushing kit for it. And the only difficult part which really isn't that hard is adjusting the float right, it needs to be at 11/32nds and the kit should provide a paper ruller for you to use. That the only thing you really need to change when you rebuild it. Other wise your basically replacing gaskets and seals for the accelerator pump. It was very easy to do in my own opinion. They also provide you with instructions, or you can go by the haynes manual if you want, they both have break downs of the carb so you can see all the parts. __________________ 1985 Scottsdale Shortbed 4x4 Stout 350 with some "upgrades"-700r4-33x12.5" Mud Tires, Warn 8274-50 winch. 2005 Chevrolet Colorado Regular Cab 2wd 4-banger, 5 speed, Street Pack with 3.73 axle.

03-12-2004, 01:40 PM	#6
lofat Rollin' Member Join Date: May 2003 Location: Hayward, California Posts: 240	sweet! Thanks for the info guys! btw - 16 mpg... wow. i would love that. i think i am pulling 11 mpg now. __________________ :: 1977 C10 cheyenne :: :: 1973 new yorker brougham :: for sale - $1,500 lofat productions

03-12-2004, 01:44 PM	#7
Destructo Registered User Join Date: Sep 2003 Location: Lewisville, NC Posts: 1,836	I was amazed I get that kinda mileage too! My speedo is a little bit off but pretty much right, maybe a couple mph off at 65 mph. So that will affect it some but not much. It was actually 16.5 but I rounded off some for compensate for the speedo being off a little. I have a 700r4 but only use third gear on the highway because my gearing it too low (3.42,s with 33's) and only turn about 2200 on the highway. Going to go to 4.56 gears and should turn about the same but in 4th gear. That will probably help out the mileage some having it able to use less power to turn the wheels but still cruise at less than 2500 rpm. And having that carb tuned and in perfect working order and a good strong running motor will do wonders for gas mileage. __________________ 1985 Scottsdale Shortbed 4x4 Stout 350 with some "upgrades"-700r4-33x12.5" Mud Tires, Warn 8274-50 winch. 2005 Chevrolet Colorado Regular Cab 2wd 4-banger, 5 speed, Street Pack with 3.73 axle.

03-12-2004, 02:27 PM	#8
MylilBowTie Right turn Clyde Join Date: Nov 2002 Location: Cincinnati, Ohio Posts: 2,911	If you want to tackle it. Get some carburetor cleaner dip, a book Rochester Carburetors: Tune, Rebuild or Modify by Doug Roe and a little bit of time. Air compressor with a rubber tip blow off tool would be nice or a can of compressed air like to clean computer dust out of the cpu. To get the residual carburetor cleaner out of the parts and to clear the passage ways. I haven't rebuilt a q-jet yet but its on the todo list. I have rebuilt 1406-1407 those are pretty easy unless the linkage (spring setup) for the secondaries comes off. Here is the link, looks to be okay I don't think any modifications where done. Like using sealant to stop the internal leak. Cant remember what its called right now. http://www.4wheelnoffroad.com/qjet.html __________________ 1974 C25 LWB: 454 4bbl Carb / TH400 / 3.73 1992 Camaro RS 305 TBI

03-12-2004, 02:42 PM	#9
ocbaud Garage Queen Material Join Date: Oct 2002 Location: USA Posts: 4,129	if i were to decide on using my stock qjet off my 305, on my new engine, how would i need to build it up to perform great?

03-12-2004, 08:20 PM	#11
NeCrOmAnCeR Registered User Join Date: Feb 2004 Location: Hodgenville, Ky Posts: 735	Here are a few q-jet performance mod links for you ocbaud http://www.geocities.com/gtopercy/Pi...rajetTech.html http://www.buickpartsdirectory.com/Q...ning_Paper.doc I have found these to cover most mods I have done to a q-jet.



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