Carb question

[rgtrough]

Hey guys, in the specs for the carb on a 1974 L-82 all it says is 1x4 bbl roechester. Does anyone know the rated cfm? Thanks for any info. peace Bud

 

[MaineShark]

Probably 750 cfm. With a little tinkering, the Q-Jet is good for 800 or so.

Joe

 

[Stallion]

I don't think that he should shoot for 800 cfm. That might be too much carb for his engine. Wouldn't performance go down if he throws in too much?

 

[MaineShark]

I don't think that he should shoot for 800 cfm. That might be too much carb for his engine. Wouldn't performance go down if he throws in too much?

That's the beauty of the Q-Jet design. It has small primaries, so you keep your throttle response at the low end, and the large secondaries give you all the air you could ask for, up at the top. Best of both worlds

Joe

 

[AUSSIEVETTEMAN]

Q Jet

Isn't it between 750 CFM and 795 CFM?

I know my 81 is the later.

Cheers

Tony

 

[Stallion]

Right, but I think what Joe meant is that he can play with it and bore it to get more cfm.

 

[AUSSIEVETTEMAN]

Thanks.

I noticed the difference when I went back from the Holley 650 CFM DP to the Edelbrock QJet 795 CFM.
More airflow = more HP

Cheers

Tony

 

[Tom73]

The q-jets used on the Vettes are 750 cfm. There are some q-jets that were used on some olds/buicks that are around 800 cfm.

Just remember that the 750 is the max flow. Most Vette engines cannot use that much, would flood the engine. The q-jet is set up to allow only what the engine can use. That is one element that makes them such a good street carb.

tom...

 

[AUSSIEVETTEMAN]

I agree Tom.

The q-jet is set up to allow only what the engine can use. That is one element that makes them such a good street carb.

I agree Tom. I used the Holley as a boat anchor!

Cheers

Tony

 

[Stallion]

Right. I get a kick outta those people that change out their QJets and get a replacement carb. Truth is, QJet is one of the best, if not the best, out there for carbs, I think

 

[rgtrough]

Hey Tom, thanks for the info. There is no way that stock 350 cid engine can use 750 cfm. One of the big mistakes many of us make is throwing a intake and carb setup that the heads and cam can't handle. My question was for my brother who is looking for a new carb for his jeep. The adjusting aspect of the Q-jet might be just what he needs. Thanks for being here for guys like me. peace Bud