What should i do, buy a new carb, or rebuild what I've got? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 07-26-2010, 11:24 AM
Mopar or no car.
 
Join Date: Jul 2010
Location: WA
Age: 21
Posts: 34
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
What should i do, buy a new carb, or rebuild what I've got?

Hi. I've got an 85 dodge w250 pickup. Right now it has a Quadrajet on it.

It's somewhat worn out, it drives fine, but it floods at startup if you dont play with the throttle just right.

I plan to put 2.25" duels with flow masters on it soon, and then headers. Right now it has semi decent manifolds on it ( not crappy logs) a 2.25" single with a flowmaster hooked too them. i have a feeling it would really benifit from the headers and duels, the single is all smashed to fit around the transfercase.

Do you think i will need to tune it after i do that?

I'm wondering were could i get parts if i had to tune it, or if it would be a better idea to find a holley or buy a summit/holley new?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 07-26-2010, 12:07 PM
Registered User
 
Last photo:
Join Date: Jan 2010
Location: ga
Posts: 132
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Since you have a quadrajet, you have a spread bore manifold. If you wanted to switch to a holley or edelbrock, you would need to change manifolds. It's your call. I personally like a holley on everything, but the quadrajet has a lot of fans as well. Plus you wouldn't have to change intakes if you keep the quadrajet.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 07-26-2010, 12:35 PM
Hippie's Avatar
Analog man in a digital world.
 

Last journal entry: HEI comparison.
Last photo:
Join Date: May 2003
Posts: 2,255
Wiki Edits: 0

Thanks: 3
Thanked 5 Times in 5 Posts
My '86 D150 with 318, A727 and 2.94 gears came with a tired 1850 600 Holley and Edelbrock SP2P, it ran like crap and the mileage was around 7.5. I did lots of tuning and performance improved slightly and I got it up to 8.5 MPG. I rebuilt a good Holley 6919 600 for it and while it ran good mileage still sucked at 9.0. Lots of carb tuning, a new fan clutch, thermostat, headers and 3" single exhaust later performace was much better and I was up to 11 MPG. I swapped on a remanufactured Q-Jet I found on a '92 W150 "Cash for Clunkers" victim at the local boneyard. It can break the tires loose now and mileage is up to 13.8 and all I did to the carb was tweak the idle mixture a little. One of these days if I get bored I may pop the top and play with the jets and metering rods. I might even loosen up the secondary air valve later today..... just for grins.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 07-26-2010, 01:51 PM
Mopar or no car.
 
Join Date: Jul 2010
Location: WA
Age: 21
Posts: 34
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Hippie
My '86 D150 with 318, A727 and 2.94 gears came with a tired 1850 600 Holley and Edelbrock SP2P, it ran like crap and the mileage was around 7.5. I did lots of tuning and performance improved slightly and I got it up to 8.5 MPG. I rebuilt a good Holley 6919 600 for it and while it ran good mileage still sucked at 9.0. Lots of carb tuning, a new fan clutch, thermostat, headers and 3" single exhaust later performace was much better and I was up to 11 MPG. I swapped on a remanufactured Q-Jet I found on a '92 W150 "Cash for Clunkers" victim at the local boneyard. It can break the tires loose now and mileage is up to 13.8 and all I did to the carb was tweak the idle mixture a little. One of these days if I get bored I may pop the top and play with the jets and metering rods. I might even loosen up the secondary air valve later today..... just for grins.
I'm getting between 12-13.5 now.

hmmm mabey i'll stick with the quadrajet. Seeing as i'm getting roughly the same milage as you, in a heavyer truck, with the 360 and 3.55 gears.
I gained 2mpg by getting rid of the egr..
Do you know what kinda rpm's your truck runs at on the highway? I'm running right at 1900-2000 at 60.
Any idea why it would flood out when you first start it? Right now i have to crank it, then it will catch, and if i dont feather the pedal it will stall and flood.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 07-26-2010, 03:04 PM
Hippie's Avatar
Analog man in a digital world.
 

Last journal entry: HEI comparison.
Last photo:
Join Date: May 2003
Posts: 2,255
Wiki Edits: 0

Thanks: 3
Thanked 5 Times in 5 Posts
Quote:
Originally Posted by TireTracks
I'm getting between 12-13.5 now.

hmmm mabey i'll stick with the quadrajet. Seeing as i'm getting roughly the same milage as you, in a heavyer truck, with the 360 and 3.55 gears.
I gained 2mpg by getting rid of the egr..
Do you know what kinda rpm's your truck runs at on the highway? I'm running right at 1900-2000 at 60.
Any idea why it would flood out when you first start it? Right now i have to crank it, then it will catch, and if i dont feather the pedal it will stall and flood.
I'm turning 2100 at 60 with 235/75-15 BFG All Terrains if my tach is right but I beat the snot out of mine. I suspect I might actually get a little better mileage with 3.55 gears so the 318 didn't have to work so hard to get it rolling but we'll never know. This is a beater truck and I'm not putting any more into it. If something like the trans goes I'll part it out and send it to the crusher.

As to your carb problem, Q-Jets have well plugs in the bottom of the fuel bowls that will leak into the intake causing the engine to "flood" on startup. Your problem is a classic example of what happens. That would be my bet although other things can cause it. The fix is to rebuild the carb and seal these plugs with a gas proof epoxy. The carb body has to be spotless so the epoxy will stick, I use JB Weld myself.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 07-26-2010, 04:04 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by TireTracks
I'm wondering were could i get parts if i had to tune it, or if it would be a better idea to find a holley or buy a summit/holley new?
Personally, I would try to keep the Q-jet. It is a hell of a carb and if you ever drive a vehicle w/a Q-jet on it properly tuned, you'd surely like it a lot.

Gessler has most if not all of the hard to find small parts you could ever need.

Edelbrock carries various Q-jet carb tuning parts.

Ruggles has quality parts and rebuild kits and services like primary bushing installation. He does correct restoration of Q-jets, and has a highly regarded book on working w/the Q-jet called How to Rebuild and Modify Rochester Quadrajet Carburetors.

Another book is By Cliff Roe, called Rochester Carburetors. Most say they'd probably get the Ruggles book first.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 07-28-2010, 12:19 AM
curtis73's Avatar
Hates: Liver. Loves: Diesel
 
Last wiki edit: How to find cheap parts
Last journal entry: 1999-2001: Getting it on the road
Last photo:
Join Date: Dec 2005
Location: Pittsburgh, PA
Age: 40
Posts: 5,128
Wiki Edits: 16

Thanks: 0
Thanked 2 Times in 2 Posts
Like many engine parts, the carb is not "worn out" it just needs to be remanufactured. A carb is a chunk of aluminum with mechanically selected parts. If it is not acting right, it needs to be at least rebuilt, maybe remanufactured.

Qjets are very complex yet accurate carbs. Their main flaw is that the throttle shafts ride directly on the aluminum. Aside from a rebuild kit and new float, the most you will probably need is a $60 kit from Jet to bore and bush the throttle bores.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 07-28-2010, 11:33 PM
Mopar or no car.
 
Join Date: Jul 2010
Location: WA
Age: 21
Posts: 34
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
So, i'm kinda worried about buying all the parts for my quarda jet ( eek, they are expencive compaired to holley parts) that i'm worried about messing it up and wasteing my money.

I've never rebuild anything more complicated than a briggs carb, i've only bearly messed with the holley on our IH when it was gummed up.

Do you guys think i would be able to rebuild it if i got one at the Junkyard to tear apart and see how it's put together?, im fairly mechanicaly inclined, just have never messed with the black magic parts of a carb.

I'll see if i can find one of those books localy, though it seems anything thats not holley is hard to find here.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 07-29-2010, 05:42 AM
345 desoto's Avatar
Registered User
 
Last photo:
Join Date: Sep 2006
Location: Skaneateles, NY Summer/Port St.Lucie, FL Winter
Age: 71
Posts: 416
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I would STRONGLEY suggest keeping the Q-Jet. It's probably one of the best carburetors ever designed. Contact this gentleman...he is an absolute Q-Jet Genius! Period... http://www.cliffshighperformance.com/
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 07-29-2010, 06:15 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 59
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 597 Times in 546 Posts
Quote:
Originally Posted by TireTracks
So, i'm kinda worried about buying all the parts for my quarda jet ( eek, they are expencive compaired to holley parts) that i'm worried about messing it up and wasteing my money.

I've never rebuild anything more complicated than a briggs carb, i've only bearly messed with the holley on our IH when it was gummed up.

Do you guys think i would be able to rebuild it if i got one at the Junkyard to tear apart and see how it's put together?, im fairly mechanicaly inclined, just have never messed with the black magic parts of a carb.

I'll see if i can find one of those books localy, though it seems anything thats not holley is hard to find here.
On thinking back to my first go-round w/a Q-jet, the couple stumbling blocks I ran into were the roll pin to release the accelerator pump (don't push it against the air horn on removal), getting the power piston, which holds the primary metering rods, into position w/the rods in the jets (this op is done basically blind), and holding the accelerator pump/piston/spring assembly in position while fitting the air horn back onto the main carb body (need an extra thumb) lol.

I didn't have any books, and this was pre-interweb, but I managed to get it all back together w/o any real problems (nothing broken, lost or otherwise messed up) and it ran fine.

But nowadays, there's so much info available w/photos and step-by-step instructions, that I believe you or anyone w/a modicum of ability and desire can successfully rebuild a Q-jet, or any other carb.

And as long as you don't outright lose parts or destroy something, somehow there's virtually no way that you couldn't get it back together eventually- even if the first time gives you problems.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 07-29-2010, 09:08 AM
Mertz's Avatar
Member
 
Join Date: Jun 2002
Location: Reardan, WA
Posts: 665
Wiki Edits: 0

Thanks: 1
Thanked 3 Times in 3 Posts
Qjet is an easy rebuild if you do things in the right order. The rods are hard to get into the jets but will go and you know they are in when they do go. The new carbs have a screw holding on the choke valve which makes pulling and putting the top back on much easier. I have taken mine appart so many times getting the jeting right that I can remove it from the truck, change jets and rods and have it back on and running in 20 minutes. The first time is the time to learn so I used a carb I had laying around that I wasn't going to use.

I am getting 16 mpg with mine in a 72 Chevy 350 with 350 turbo and 3:08 gears.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Need some pointers for cleaning up carb for rebuild eric32 Engine 1 02-13-2010 07:36 AM
I need a carb. rebuild kit for my bone stock 1950 Studebaker Champion ret_marine2003 Hotrodding Basics 11 08-19-2009 06:52 AM
rebuild carb demon Mikeymuy Engine 2 03-12-2009 07:36 AM
Solex carb rebuild Kaefer'60 Engine 2 11-25-2004 05:53 AM
carb rebuild kit 67stang Engine 7 01-23-2003 01:20 PM


All times are GMT -6. The time now is 04:24 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.