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Rochester to Holley carb conversion...help in Uk needed!

P

pvsiconic

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Hi there from across the pond, hope you're all well,

I have just bought a 1980 C3 after 3 years of searching on and off for a black one and settled on a Bronze (well lets be honest its brown!) C3 as its the best one I could find.... and a repaint for me aint too expensive!

The problem I have is that the Q-jet just isn't playing ball. I have reaed Lars thread from end to end and although its brilliant I can't find my symptom there.

The car has always run a little fluffy (rich!) at idle (the last guy owned for 8 years and lived with the problem). I had a good look around and I thought I had found the problem, the primary jets were leaking at idle, dripping onto the butterflies (throttle body flaps I think you call them?).
I rebuilt the carb' and nothing improved, I then noticed the airhorn was as bent as a banana, and I'm thinking I have found the problem!!!
....I refaced the airhorn and it still drips fuel from the primaries!

The float height is set to 15/32's, the primary idle jet needles aren't bent but if I push down the powerpiston using a screwdriver (with care!) when the engine is running the primaries still leak, is this witchcraft or something?!? Could the powerpiston 'stop height' be set wrong so my primaries are always open, if so how do reset?

The carb does have an incredible amount of wear for the miles, with worn bushes everywhere but I broke out the ID and its the original carb'.

I'm now thinking of going for a new Holley 600 cfm vac' secondary conversion but this means I need a spreadbore to sqaurebore convertor and I ain't too sure if these work OK....I do prefer the Holley but can apphreciate the engineering in the Q-jet! Do I get a rebuilt Q-jet and hope that its been rebuilt correctly?

any help gratefully received

cheers for now

Richard
 
Richard, edelbrock makes a spread bore carb that will fit on your stock manifold. another suggest the local speed shop gave me(if i don't like the edelbrock i am testing).was the holley street avenger. it's supposed to be a new plug-and-play version. you may want to also consider changing the intake to one of the edelbrock performer series. they will allow you a wide variety of carb choices and will still be able to close the hood.

cheers

robin

btw... bronze does sound much cooler
 
I agree with Robin.

The Street Avenger series is a good product, and I believe that they offer a Q-Jet version (Model 4010 or 4011).
 
thanks!

many thanks for your prompt replies guys....the Edelbrock seems to be the way to go.

.....I know the old Q-jet is tired but I would really like to know why its giving me the problems I have before I spend the money on the new carb...it would sure help to justify the price we have to pay over here for the US carbs!

cheers for now and again many thanks for your help

Richard
 
Hi Richard,

Have you joined the CCUK yet and are you going to the monthly meetings up at dartford?? Hope to see you and your car there soon.

Paul.
 
I went for an Edelbrock and it has been no problem, ran perfectly straight out of the box and was easy to work with after I did the engine, much more straightforward than the Holley I replaced. The dollar to pound is good just now so if you can wait it might be cheaper to order one from a US supplier rather than pay for one in the UK that someone has had on the shelf for a while. I have bought a lot of bits this way and if you stick with the big names such as Summit Racing or Jeggs you will have no problem.


J.
 

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