Looking to possibly swap out the quadrajet on the 72 Olds for something a little newer.... I'm sure there are threads out there on this, but I figured engine configuration may make a difference, so thought I would ask. I have a 72 CS, with the 350 in it, Cam with 270D/501L cam in it, nothing else has been done. Stock TH350 tranny. I'm not real crazy about the q-jet, as I believe that they are difficult to tune properly. So, in short, based on that info, what would be a good replacement carb for it? Or would rebuilding the q-jet be better? I would just like the car to run a little better, and be a little easier to start. I have to pump the hell out of the thing just to get it started. Thoughts? Thanks in advance all.

 

If the car has been sitting, filling the bowl will be required no matter what carb you put on there. The issue is the quadrajet is a spread bore carburetor, anything else will require an adapter or a change in manifold. The quadrajet is no more complicated to tune as any other carb out there.

 

My personal recommendation is keep the QJet, but I am very familiar with them as I have been using them since the 80s and have learned a lot about them over the years.

Why not rebuild your QJet (or have it rebuilt) to see how it performs as that can be done very inexpensively, then if you are still disappointed, fork over a wad of cash for a new carb.

 

Whoa, am I reading this correctly? You have a stock 1972 350 with 8:1 compression ratio, a .501" lift, 270º duration camshaft, and a factory stall converter? If that is correct, I think your engine is overcammed and your transmission is under-stalled (is that a word?), and no amount of carburetor work is going to fix that.

 

Well, let's put it this way, it's stock as far as I know. I bought it after my dad passed away, it was his, and the engine was on its last leg. It required a new crank and 2 new rear pistons, and the guy who built it for me said it looked like whoever had rebuilt it before had likely not gotten things lined up correctly, and that it looked like maybe the torque converter wasn't lined up properly when it was put back in. So, they honed all of the cylinders, and balanced the pistons. I asked them to throw a mild cam and lifters in while they had it apart, so that's what they elected to put in there. It runs great, sounds great, it's just difficult to get it started. But like oldcutlass mentioned, it does sit around a LOT, I haven't really driven it in close to 2 years. But I can't part with it for personal reasons. I do want to start driving it more though. The carb may just need to be rebuilt, I'm not sure when it was done last. Thanks for the replies fellas.

 

Any car w/ a carb will never start as readily as one w/ EFI, ESPECIALLY when it is allowed to sit more than a day or two without running. EFI fuel systems are really simple; electric pump in the tank never has to suck fuel through a 20' straw and pressurizes the injectors within seconds of turning the key. Carbs have bowls of fuel that dry out over time that have to be replenished by a mechanical fuel pump that only works when the engine is cranking and has to suck the fuel from the tank through the aforementioned 20' straw. THEN, once fuel gets into the bowl, you still have to pump the pedal a bit to set the choke, and then hopefully squirt some fuel into the intake to prime it. If you didn't kill the weak battery by the time fuel reaches the cylinders, you'll finally get it to fire up.

Recommendation, when trying to start your car after sitting more than a day, kick the gas once to set the choke, turn the key, crank the engine and give it time to get fuel into the carb bowl, kicking it again every 2 or so seconds to prime it, and it should fire. Kicking the gas rapidly is a good way to accidently flood it.

 

Send the carb out to a professional rebuilder/restorer to bring it back to original, or invest in a new bolt on fuel injection TB unit.

 

Also, you don't need to pump the hell out of it to get it started. Pump it a few times fully to set the choke, turn the key on, and crank. It should start within ten seconds. Pumping gets fuel from the bowl, just like the main jets and idle circuit, until fuel gets to the bowl, pumping does nothing. If it is "trying to start", pump then once or twice.

 

I'm in the process of installing an electric fuel pump (with a bypass) to prime the carburetor prior to starting.

 

Thanks all, I'll check it out. I'll have to go out and look today, but i THINK it may have an electric choke set up. That might be an issue with it as well.