Quadrajet questions

[rustytoolss]

During the years mopar installed Quadrajets ( the ones with out any electronics) on FMJ cars. Does anyone know what CFM they were, where the 318 different CFM, that the 360 CFM ? Does any one know what the throttle bore sizes were ? part numbers ? Thinking of installing a QJet for mileage. I do have a TQ, but it has fuel leakage issues. I have never had those kind issues with a QJet.

 

[AHBguru]

There was only 1 non-feedback Q-Jet used on cars, which were the export models from '85 and '86. Rochester carb number was 17085411.

CFM on the QJet was a little bit under the small TQ, about 750 CFM.

You'll probably have a hard time finding the 5411. I'd recommend considering a 17085408, or 7175. These were light-duty 360 Q-jets that should be ok on a 318 with the J-head 587 or 345 casting that the M-body Pursuits used.

If you can't find those (the 5408 was probably the most popular, outside the E4ME 17085433 used in the squads), look for a 17085432 or 17087175. You may have to rejet the latter two, but in my experience, they should be just fine.
Try to find an AC Delco rebuild kit, if possible. Don't forget the little filter inside the fuel inlet.

I had very good luck with the Q-Jet on the 318 and 360. They're easy to build and tune, they hold their tune longer than the TQ, and the choke set-up is much better in the winter. That said, the TQ performs better, and are happy tuned as lean as you dare.

 

[rustytoolss]

There was only 1 non-feedback Q-Jet used on cars, which were the export models from '85 and '86. Rochester carb number was 17085411.

CFM on the QJet was a little bit under the small TQ, about 750 CFM.

You'll probably have a hard time finding the 5411. I'd recommend considering a 17085408, or 7175. These were light-duty 360 Q-jets that should be ok on a 318 with the J-head 587 or 345 casting that the M-body Pursuits used.

If you can't find those (the 5408 was probably the most popular, outside the E4ME 17085433 used in the squads), look for a 17085432 or 17087175. You may have to rejet the latter two, but in my experience, they should be just fine.
Try to find an AC Delco rebuild kit, if possible. Don't forget the little filter inside the fuel inlet.

I had very good luck with the Q-Jet on the 318 and 360. They're easy to build and tune, they hold their tune longer than the TQ, and the choke set-up is much better in the winter. That said, the TQ performs better, and are happy tuned as lean as you dare.

Ball park idea of fuel mileage with quadrajet over stock carter 2 barrel BBD...thanks for the information

 

[AHBguru]

The TQ might give you decent mileage. The Quadrajet uses a little more fuel in my experience. Not a significant difference in town. On the road, with everything else being relatively equal, maybe 1-2 mpg less than the TQ. You can tune the QJet leaner, but it won't be happy. I never bothered. The Q-Jet has much better drivability when set up right.

For the best mileage, a properly tuned '85+ Lean Burn/Feedback system can't be beat. No two ways about it. If you want to run regular electronic ignition, look for a 2280 Holley, which is the non-feedback version of the BBD used after 1984 in pickups and export cars. Make absolutely sure your timing is dialed in - figure 7 -9° BTDC base, and at least 50-60° BTDC, all in, at 4000 RPM.

 

[Vaanth]

During the years mopar installed Quadrajets ( the ones with out any electronics) on FMJ cars. Does anyone know what CFM they were, where the 318 different CFM, that the 360 CFM ? Does any one know what the throttle bore sizes were ? part numbers ? Thinking of installing a QJet for mileage. I do have a TQ, but it has fuel leakage issues. I have never had those kind issues with a QJet.

The preferred numbers have been described, but the following lists the Quadrajet part numbers, used by Chrysler after the Thermo-Quad was discontinued, with both electronic feedback and non-feedback versions.

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Rochester Quadrajet Listing​

Carter ceased production of the Thermo-Quad after the 1984 model year. Chrysler switched to the Rochester Quadrajet M4ME and E4ME for 1985-1989.

• M4ME = "Modified" (post 1974), 4 barrel Quadrajet, electric choke, non feedback.
• E4ME = Electronic feedback, 4 barrel Quadrajet, electric choke.

Following is a listing of these carburetors for reference.
NOTE: The identification number is stamped vertically on the left side near the secondary throttle lever.

Rochester Number	Application​	Chrysler Number​	Details​
17085407​	85 318​	4306407​	O2 E4ME; Service #4342805​
17085408​	85-87 360 Truck ​	4306408​	AT Fed; Service #4342806​
17085409​	85 318 85-87 360 Truck	4306409​	Fed O2 E4ME; Service #4397609 AT Fed HA O2 E4ME; Service #4342807
17085411​	85-87 318 ​	4306411​	Can Exp; Service #4342808​
17085414​	85-88 360 Truck​	4306414​	HD​
17085415​	85 360 Truck ​	4306415​	Fed CA Can HD; Service #4342810​
17085416​	85-88 360 Truck​	4306416​	LD, Fed, CA, Can​
17085417​	85-87 360 Truck ​	4306417​	MT Fed; Service #4342914​
17085425​	86-88 360 Truck ​	4306425​	Fed; Service #4443060​
17085431​	86-88 360 Truck ​	4306431​	HD CA Can; Service #4342932​
17085432​	86-88 360 Truck​	4306432​	HD​
17085433​	86-89 318​	4306433​	O2 Fed CA Can E4ME; Service #4397609​
17085434​	86-87 360 Truck​	4306434​	AT Fed CA Can; Service #4443060​
17087175​	88 360 Truck​	4306419​	AT, Fed​
17087176​	88 360 Truck​	4306420​	MT, Fed​
17087177​	88 360 Truck​	4306424​	AT, Fed, HA​
17087245​	88 360 Truck​	4306437​	Fed, CA, HD​

Table Abbreviations:

• AT = Automatic Transmission
• MT = Manual Transmission ( No reference means both transmissions )
• CA = California application; generic for CA, Sales code N95
• Fed = Federal application ( No reference means both Federal and California.)
• Can = Canada application. Typically, Canada used Federal carburetors except as noted.
• Exp = Export
• HD = Heavy Duty Cycle
• HA = High Altitude
• O2 = Feedback unit

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[rustytoolss]

The preferred numbers have been described, but the following lists the Quadrajet part numbers, used by Chrysler after the Thermo-Quad was discontinued, with both electronic feedback and non-feedback versions.

---

Rochester Quadrajet Listing​

Carter ceased production of the Thermo-Quad after the 1984 model year. Chrysler switched to the Rochester Quadrajet M4ME and E4ME for 1985-1989.

• M4ME = "Modified" (post 1974), 4 barrel Quadrajet, electric choke, non feedback.
• E4ME = Electronic feedback, 4 barrel Quadrajet, electric choke.

Following is a listing of these carburetors for reference.
NOTE: The identification number is stamped vertically on the left side near the secondary throttle lever.

Rochester Number	Application​	Chrysler Number​	Details​
17085407​	85 318​	4306407​	O2 E4ME; Service #4342805​
17085408​	85-87 360 Truck ​	4306408​	AT Fed; Service #4342806​
17085409​	85 318 85-87 360 Truck	4306409​	Fed O2 E4ME; Service #4397609 AT Fed HA O2 E4ME; Service #4342807
17085411​	85-87 318 ​	4306411​	Can Exp; Service #4342808​
17085414​	85-88 360 Truck​	4306414​	HD​
17085415​	85 360 Truck ​	4306415​	Fed CA Can HD; Service #4342810​
17085416​	85-88 360 Truck​	4306416​	LD, Fed, CA, Can​
17085417​	85-87 360 Truck ​	4306417​	MT Fed; Service #4342914​
17085425​	86-88 360 Truck ​	4306425​	Fed; Service #4443060​
17085431​	86-88 360 Truck ​	4306431​	HD CA Can; Service #4342932​
17085432​	86-88 360 Truck​	4306432​	HD​
17085433​	86-89 318​	4306433​	O2 Fed CA Can E4ME; Service #4397609​
17085434​	86-87 360 Truck​	4306434​	AT Fed CA Can; Service #4443060​
17087175​	88 360 Truck​	4306419​	AT, Fed​
17087176​	88 360 Truck​	4306420​	MT, Fed​
17087177​	88 360 Truck​	4306424​	AT, Fed, HA​
17087245​	88 360 Truck​	4306437​	Fed, CA, HD​

Table Abbreviations:

• AT = Automatic Transmission
• MT = Manual Transmission ( No reference means both transmissions )
• CA = California application; generic for CA, Sales code N95
• Fed = Federal application ( No reference means both Federal and California.)
• Can = Canada application. Typically, Canada used Federal carburetors except as noted.
• Exp = Export
• HD = Heavy Duty Cycle
• HA = High Altitude
• O2 = Feedback unit

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Thanks for all the information, and the added web pages !!

 

[Shorty Thompson]

During the years mopar installed Quadrajets ( the ones with out any electronics) on FMJ cars. Does anyone know what CFM they were, where the 318 different CFM, that the 360 CFM ? Does any one know what the throttle bore sizes were ? part numbers ? Thinking of installing a QJet for mileage. I do have a TQ, but it has fuel leakage issues. I have never had those kind issues with a QJet.

650cfm. Nw if you wanna get away from all that electronic stuff, then just pull the bottom plate off a put it under a Chevy Quadra-jet.