Rochester Q-jet carb vs Holley 770 cfm

[Francesco]

The flaps may not be stuck. Will the primaries open if you turn the throttle by hand? If so, crank it wide open and then the secondaries will open. The linkage locks the secondaries out until the primaries open to a certain point.

Great carb! Give Cliff Ruggles a call and give him your carb number. He has great rebuild kits and will talk to you about Qjets as long as you let him.

Yes, the primaries will open. I guess I just learned something new again. Thank you Brent!

 

[biker]

You are welcome Sir!

 

[1980RS]

How did you adjust it to work properly? Also, I didnt know that you can match a Q-jet with a vortec intake. With those L31 I got last year, I wonder how it will all work out. Sounds interesting...

It's not an adjustment, you need to add the brass primary side tube to the 770 to make it work right. I have done several vs Holley's to make them work right.

 

[Francesco]

Apparently, these things were customized for specific engines. Best way is to choose one that was on a brand and engine size similar to yours. Even the rear gear ratio plays in that. Thats interesting.

 

[kdsracing]

Hello guys! I just found my orginal Rochester 4 barrel carb lying around in the basement. I just needs a cleaning and a rebuild kit. The number is 17080229. I want to swap it with the actual one on my engine. Its a Holley 80770 model. How is the Rochester better than this Holley aftermarket carb?

Thank you

Other than being original, it isn’t better in my opinion.

 

[kdsracing]

Since the "Q" jet is a spread bore carb . You usually get better fuel mileage

The Holley Qjet replacement is also a spread bore.

 

[1980RS]

The Holley Qjet replacement is also a spread bore.

Yes it could be named that. The Holley replacements were call the 6210 650 Spreadbore. If you want a carb that does not need a lot of fussing around with the Holley replacements work great, ran several over the years. Just do not use the vs one for towing the engine will suck the sec side open even with the black spring in the pod and kill your fuel mileage.

 

[Francesco]

The Holley Qjet replacement is also a spread bore.

My holley is a squarebore and its just wasting gas. Ive had it for 14 years. I got the Q-jet for 150$ 10 years ago. Im reading about this carburetor as being a very good driver tool. Thats what I want. I want to save from having to buy a better street friendly holley.

 

[PThomas]

The quadrajet will just need to be dialed in initially, and you shouldn't have to mess with it anymore after that. Every Holley I've used has been temperamental.

 

[G72Zed]

I've seen some "new" Holley carbs of certain "lines" that were absolutely junk right out of the box. I've also seen some that had internal leaks due to porosity that caused the old "holley gas burning" reputation no matter what it was on, just saying.

That being said, some of the older ones are some of the best ones I've built, as the old saying goes, "you get what you pay for" in these cases for the most part.