I spoke with Roush today, they seemed to not know much about it and recommended dealing directly with Holley.

I e-mailed Pro systems to get a quote for a new one.

I guess I could just send my current carburetor into Holley and see what they do with it, hate to be without the car for a week or so being that I just got the car and the weather is finally getting nice :)

anybody else have good results with pro-systems. My uses will be solely for the street.

just ordered a pro systems double pumper carburetor, Patrick over there seemed very knowledgeable.

You just saved yourself a ton of headaches. When you get the new carb, put the Street Avenger on Craigslist. I got $200. Sold it to a guy who is building a street Mustang. Perfect for that car.

You will probably have to adjust the 4 idle screws and set the float level, but when finished, you will not be disappointed. Patrick will talk you through any adjustments. I called him on a Saturday while he was at the race track and he took the time to help me remove a couple of idle restrictors from the metering blocks that were not needed by my engine.

I agree with the first part, I,too have used and tuned a lot of vac. sec. Holleys, some took more tuning than others, but I eventually got them to work properly for the application....Ran a vac. sec. 600 holley on my car for years with no problems, once tuned to my engine, I never had to touch it again......

Second part about double pumpers is where I disagree.......while running the 600 vac.sec. Holley, a buddy gave me an old 600 Holley double pumper he was throwing away, said it never ran right on his 289....I took it for parts, that carb had to be at least 15 years old when I got it. It sat on the shelf in my shop for a couple of years before I decided to take it apart and look it over. Turns out he had it jetted about 10 sizes too big for his practically stock 289....all I did was give it a good bath after taking it apart and re-jet it to what I thought would work best on my 351-W.Changed the jets one time,set the floats and have been running it for at least 10 years now, no problems what so ever, actually,best carb I ever had....I find double pumpers are very street friendly and my gas mileage has not changed by any noticeable amount, but off idle performance is much better.....
I'll take a double pumper any time,even for street driving.......

David

I have tuned a lot of carbs that had been other places---In most cases I look to see what jets, power valves, squirters are in them and look at Holleys specs to see what they built them with---generally they will be way off from the settings built by the factory----putting them back to stock( with the exception of pv which I do by vacume ) usually will make most of the problems go away and gives me a good starting point for dialing them in---Lots of carb problems are also fuel pressure or timing curve related----

I do the exact same thing...Have 2 big Holley books in the shop that I refer to all the time...one is a very comprehensive "spec book" and the other is a re-build book.......It's amazing what I've seen in some "used" Holleys....Different floats on each side and some holes drilled in wierd places....The only carbs I have had major problems with are the vac. sec. Avenger line of carbs, for some reason, there seems to alway be a small problem that can't be worked out of them....
To me, double pumpers are the easiest to work on and tune,that's why I like them over the vac. sec. carbs.....
David

My Holley double pumper had a stumble when the secondaries opened. Turned out it was squirting too much gas. Actually had to grind down the secondary cam so that it would not lift the accellerator pump so much.


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the following link is the actual carburetor Patrick is building , for my 342 it will be a 780 CFM and his build time is about five days.

http://www.prosystemsracing.com/proseries4150.html

Let us know how you like it once you get it installed and dialed in

CobraEd

Thats why they make so many pump cams and squirters---also the cams will go on two ways

Yep, a long time ago I bought a Holley "tune-up" kit, it came with a bunch of pump cams,squirters and the whole assortment of springs for vac. sec. carbs,very helpful when tuning a carb.....plus thru the years,I've dismantled at least a dozen old Holleys, for parts, I don't throw away much, save the jets/squirters/metering blocks/float/neddles,seats and such, never know when you'll need a little part and I've gone into that stash many times for odd and end parts..........

David

carburetor update.

Last-minute change of plans I decided to take holleys offer of sending my carburetor in for them to check out.

I sent the carburetor in just as I purchased the car I did no adjustments to it.

they received the carburetor and got right to testing it, it was on its way back to me within two days.

Best that I could get out of them was the tech that worked on the carburetor noted the primary was way out of adjustment and the secondary was opening way too far. he also noted that it had a peculiar 50 CC pump or something installed,he believed that's because it was a Roush tuned 770 not stock.

I reinstalled the carburetor started right up a friend of mine gave it to slight quarter turns to lean the bottom out and it runs fantastic!

Feels like a totally different motor. Absolutely no stumbling, runs like a bear from idle to top-end:)

For now I cannot imagine needing more it feels as if I push into the throttle hard enough I will flip over backwards :-)

I tried all cams in the kit. Nothing worked.


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You mean Sec. were opening way to fast right?
I had a BG 650 VS. As far as I was concerned the car was running really good, but I had no control over the secondaries, they came in smooth and it seemed like slow motion. I know that's the way its suppose to feel but I like the feel of a cobra, the connection to the motor and road, the snapping forward on deceleration and instantaneous reaction to let and right turns. I knew that I wanted a mechanical secondary carb. I called Patrick at Pro-Systems and he made a 780 for me. I bolted it on, warmed it up, made my adjustments and took it out for a test. EXACTLY what I was missing, [CONTROL, & AGGRESSIVENESS]. I am happy with my replacement. I'll keep my BG because the Pro-Systems Carb is staying with me if I ever sell my car.
Lou

They were opening too fast and too much. Had to grind down the nylon cam. The actual jetting for the secondaries was dead on. It was just too much secondary accellerator pump.


The difference in driving a car with mechanical secondaries compared to vacume secondaries is analogous to the difference between driving a stick shift car compared to an automatic car. The manual secondaries increase the fun/control factor enormously. :3DSMILE:


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Well said CobraED.:3DSMILE:

Wow..I have never had a single problem with getting a Holley to work on anything. All it took was some time and knowledge of the carb and you can get it to do anything assuming the carb is not too big/small for the engine.

I always liked double pumpers, but it depends on the car.

D111,
Glad to hear your carb. is fixed and doing what it's supposed to do!! I've found Holley to be very customer friendly, and your experience only confirms it. Now go enjoy that Cobra!!

Once you get it jetted and set for your car, you will have years of good service out of a Holley.


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I am glad to hear you have it all worked out. How much did it cost for Holley to fix up the carb?