I have a '76 Bronco that right now is totally stock under the hood. I have been given a free Rochester Q-Jet 4-barrel from a guy at work who was cleaning out his garage. I am a big time novice at engine performance so I was wondering if sticking the q-jet on my stock 302 is advisable, and whether or not it would really do anything for me except reduce my gas mileage.

Thanks, -bu

 

what is the CFM rating of the Q-jet.

does ur 302 have a 4 barrel carb already?

stock block?


If it is still running. you didn't try hard enuf!

 

Oh yeah, as far as I can figure, the Q-Jet is a 750 cfm carb.
Right now the truck runs ok (needs a carb rebuild) with a Motorcraft 2150 2v (stock setup).

 

I am running a holler 600 cfm square bore 4 barrel with vecume secondaries. I have to have the second stiffest spring for the secondaries to stop felling the bog,

a 750 is probably going to be too much. but if you looking to go with a 4 barrel, try it. worst thing is you will have to buy a smaller carb.





If it is still running. you didn't try hard enuf!

 

How are you going to make it fit? Use a carb adapter on a
square bore manifold? Do they make 302 intakes that are
spreadbore?

 

At the risk of getting booted from the Ford fraternity let me relate a story about a friends Chevy Van. My buddy bought an 84 1ton chev van w/ blown up motor for cheap. He got a good deal on a Gen II 350 w/ vortec heads out of a 90 silverado. There was a problem though in that the new motor was a TBI injected motor and he didn't want to mess w/ finding the TBI computer and harness. So he bought an Edelbrock manifold and was going to use a carb. Q-jet #1 got rebuilt in my kitchen... got thrown away because of the complexity. Q-jet #2 from boneyard worked but he never got the choke working right, and there was a flat spot in the power band. Eventually he got a Carter AFB 625cfm. What a vast improvement. The power was better, the mileage was better, and it was set up to go out of the box. It's a more user friendly carb than the Q-jet. If a smaller carb works better on a 350, I got to think that 750 is way too much for a 302. I had a 600cfm Edelbrock on my 302 and reused it on my 390 where I think it'll stay. The 302 I have now is a stocker 2v, if I put my Edelbrock manifold on it I think I'll probably go for a 500cmf Edelbrock or Holley type. And like previous posters, I ask, how are you intending on putting a spread bore carb on a smallblock Ford? Is there a Spreadbore manifold made for it? Commonly 289/302 4V manifolds use square bore. I spose you could use grinder? I think you better pass on the Q-jet or put it on a GM.

BBT

 

[font size="1" color="#FF0000"]LAST EDITED ON 27-Jan-01 AT 07:54 PM (EST)[/font][p][font size="3" color="#191979"]

I second BBT's advice. A friend begged me to look at his Q-jet and so I did. What a complex piece of !@#$%! You would be better off with the stock 2bbl than a Quadrajunk.

If you really want a bigger carb, go to a carb from a bigger Ford engine (390's use pretty big 2bbl's), but it probably won't make much improvement on a stock engine especially one with restrictive single exhaust. The change to a 4bbl manifold will only pay off at higher RPM's - not how a stock 4x4 is typically used.

Art

 

Thanks for the input. It looks like my best option is to pass on the Q-jet and rebuild my 2 barrel.

Thanks again,
BU