J-(Chicago)

I picked up 2 Qjets this past weekend. They are both 1975 350 olds carbs.

I have no idea why these things have the regular power piston and rods,
AND 2 extra rods without removable jets. One rod is on an adjustable cylinder about 7/8'' wide, and the other looks like a regular primary power piston, except with one of the rod bosses cut off.

These things are weird. they Also have 67 jets in them.
Has anyone ever modified one of these 75's to work like the oldies'?

I made a round of phone calls to the usual neighborhood auto joes, and they all thought I was describing a U.F.O.

Oldsguy

I bet Dan (70Wcars) could help you out, he is a carburetor guru.

Danny Wiseley

My brother's 75 H/O came with what he called an "altitude compensating" carburetor. I haven't looked closely at it, as it has never given any trouble. He drove it about 190k before he parked it.

Oldsmaniac

What were you expecting to find?......computer controlled carbs I believe were 1982 issue...from what I remember the 75 Qjet is pretty similar to the earlier ones.

J-(Chicago)

Certainly not an extra pair of rods and seats.

It's very similar. I just wanted to understand these extras' functions, before I start slinging solder and epoxy about.

BILL DEMMER

auxiliary metering system, and the altitude compensation (aneroid device) to make the carb. work properly. try not to do anything non-reversible to it.


bill

J-(Chicago)

http://carburetor-manual.com/rochest...ment-a-36.html

and

http://carburetor-manual.com/rochest...dels-a-34.html

Thank you Mr. Demmer. I found these 2 articles on this.

f-85

Hey Jeremy

What do you plan to do with all these carbs? You have to have at least 10 rebuilt carbs now. LOL

J-(Chicago)

Both carbs are in decent shape, but there is a thin metal tab where the accelerator pump shaft goes through the air horn that has been damaged, and a metal plug rattling around underneath an access plate in front of it.

I want to just make them functional and drag strip adjustable again.
These were old student carburetors from a local high school. The new tech teacher, (a local gar guy I trade parts with) saved them for me when the school was throwing out all the old education program's carbs. (He's a fuel injection only guy)

The school threw out a whole cabinet full of all types of old carbs, and he only saved me this junk
Oh well, it's the thought that counts. I couldn't yell at him.

J-(Chicago)

Basically, I'm trying to have 6 or 7 carbs with different rod/jet setups for tuning at the track. I'm going to wire up the secondary locks, and tune for best primary jet times. The secondarys are easy to tune. 1 screw, lol.

f-85

You running the beast again next year?

J-(Chicago)

Probably.
Unless it catches fire or folds in half.
I gotta keep my throne in the Piece O' Junk class.

I like the shock factor of running a $200 car with all the $40K cars.

f-85

Yeah its cool seeing it on the track. Well lets shoot for 13s!

J-(Chicago)

F.Y.I.
These things have a unique power piston setup too
The primary piston doesn't have a nipple seat like the 68-74 style.
These just have a cup with no lower boss, and are shorter. I may not even be able to swap any primary rods now.