So I pulled the carb out of my '64 98 this morning to begin a rebuild. It's my first run at a rebuild, so I'm paying special attention. The only problem I see is that what I pulled out doesn't look like any pictures of the Qjets that I've seen before. Perhaps it's a later model? Would anybody be willing to let me know if this is the right carb for the '64 394? Thanks.

 

That's correct for that year although it's not a Q-Jet but is a Rochester. There's another name for it that I can't think of at the moment. I'm sure someone will chime in with it shortly.

 

I looks like it could be a very original and correct 4-Jet Rochester. What is the number on the tag?

 

It's an earlier model. Get an old Motors or Chiltons from that era. There will be diagrams and description of it's operation. Get the numbers off the carb, you may need them for the rebuild kit. Save the red tag.

 

Ah yeah I looked up the 4 Jet, that looks right. So is this a good or bad thing... I've not seen a 4 jet, though I'm still pretty new to Olds. I'm at work right now so I can't pull the numbers, but I'll get them up asap. I take it the red tags tend to get lost?

 

As noted, it's a Rochester 4GC, the predecessor to the Q-jet. Correct for 1964.

 

I found the service manual for this online for free at newagemetal.com. Are these any more desirable than the Qjet or just different? Anybody know a good place to get rebuild kits for these? I tried to get one through NAPA, Autozone, and O'Reilly but the suppliers are all out of stock or they no longer carry them.

 

Try Carquest - They can still get most of them

 

Thanks, I'll give that a go. I guess I assumed all of the 64s came with the quadrajet. I guess you learn by doing.

 

Actually, none of them did. 1965 for some big cars and 1966 across the board.

 

You learn something new every day. I must have had my years mixed up fromt he start! Thanks.

 

When you tear that carb down, SAVE AS MUCH OF THE ORIGINAL GASKETS AS POSSIBLE. You'll need them to match the new ones. 4GC are sensitive to using correct gaskets between the float bowl and throttle body, and the wrong one for the application will make one do hateful things.

You will find brass twin floats inside as well as a few screens that QJets don't have. 4GC do not have any metering rods.

 

measure accurately too. the floats may be different from the primary side to the secondary side, mark them to make sure you get them back in their correct places. if you have a digital camera, take lots of detailed pix as you disassemble it. from time to time, these carbs. require throttle shaft bushings too. after you clean the throttle body, check to see how much play there is in the shaft bores by trying to move the shafts backward and forward and up and down with the throttle open about 1/4 of the way. be careful of small parts that are overlooked during dis-assembly, they fall out of hidden places. make sure nothing falls/rolls off the bench.

best of luck!


bill

 

I have several NOS carb kits. I may have the one you need.
If you're interested, post the carb part number and I'll check.

 

I bought a carb kit from Car Quest about two months ago for my '57 Super 88 4 bbl...

 

It's 7020955 E 90 on the tag. I've got my digital camera out and am taking pictures every few minutes... I'm paranoid that I'll miss something

 

To clarify several of the above posts, both the 4GC and Q-Jet were Rochester carbs.

Norm

 

Daytona Parts Co. (google 'em) will have the right kit. They did for my 4-Jet, on a 55 Caddy.

 

So I'm almost done breaking it down. I found a rebuild kit. I took a look at the old gaskets and I'm wondering... is this the original gasket? The thing is about 1/8 inch thick and brittle as hell. It feels like 45 y/o rubber to me.

 

looks right to me, it isn't rubber, it's basically paper.


bill

 

Yeah I knew the replacements were a paper compound, wasn't sure if the originals were something different. It feels so brittle, age hurts I guess.

 

Tell me about it! My knees, my shoulder, my neck, my........

 

1964 4GC Carb Manual here:
http://www.carburetor.ca/pdf_manuals...er4GManual.pdf (20MB)

Page by page here:
http://oldcarmanualproject.com/manua...eMan/index.htm

 

Mmm free manuals... thanks!

 

Some of my manuals called the Rochester 4GC a "quadrijet". The later carbs are quadrajet.

 

I've seen them with 4-Jet, Quadri-Jet and MultiJet cast into their airhorns. They were an OK carb, but it's telling that the other GM Divisions either didn't use it or used it only on low-performance applications. Cadillac and Olds were the only ones who used it across the board. Pontiac and most Buicks used Carter AFBs and Chevy diddled back and forth between them depending on how hot-roddicus the engine was.

My experience with 4GC is that they either work right or they don't. The original one to the blue Starfire was a disaster- I couldn't get it to work right, and sent it off to a 4GC guru. He messed with it and finally told me to scrap it. Never could get the choke and fast idle set properly. If the choke worked, it never kicked off fast idle. If you set it up to where it would idle down properly, the choke did not work. Moving the choke coil one half notch would move the problem around.

The best one I ever had developed an unstoppable fuel leak at the fuel line inlet nut. So it too went to the scrap heap.

4GC carbs are one reason I'm considering upgrading the SlimJims in those cars to Turbo HydraMatics. You get rid of the Slim Jim, you get rid of the TVR linkage adjustment headaches if you change over to an AFB carb.

 

I know that Buicks did use these carbs, as I had one with the starter vacuum switch on the right side of carb. I have noticed that some of these carbs do not seal well from air horn to main body. If I had a choice, I would go with AFB.

 

I would like to see a picture of how your vacuum lines are routed as I am putting that same carb on my 61 replacing the 2 barrel.

Thanks
Pat

 

I'll take some pictures as soon as I get it back in