Carb replacement

Mike,

No experience with the Quick Fuel Tech carbs. They are, of course, just a "designer" carb, a modified Holley, there are many such carbs on the market these days. Even Holley offers a "tuner" version of their own carburetors, called the HP series. I've read & heard of people having good luck with the Holley HP carbs. I think the bottom line is whether or not you believe the QFT metering plates are worth the premium money you'll pay for them. Keep in mind, most if not all Holley based designer carbs eliminate the choke assembly, which means you have to sit and pump the gas pedal while the car warms up.

I have a more basic question however, if your motor is stock, why not use the Autolite 4300D? Is it doing anything wrong? Are you after a little racier look? Or are you planning a "one step at a time" upgrade of the motor?

In my opinion the Autolite 4300D cannot be beat for a stock motor (the 4300A is too small). It lacks the racy looks of a Holley with center hung fuel bowls however. The Edelbrock (which is a Carter AFB) is a good carb, it has a loyal following, they are tune-able, but they are not available in as many sizes as Holleys, and their fuel bowls will not support the kind of BHP the Holleys fuel bowls are capable of supporting. The Carter is mechanically more simple, fewer castings & gaskets, tuned with needles from the top.

What I would recommend for you depends upon what your end goals are.

cowboy from hell

George: Thanks for the advice. My main problem with the stock carb is what appears to be vapor lock on hot days. The car will be running fine, then all of a sudden, just starts sputtering, then dies. After a little while, it will start right up and run fine. Other than a cooling system upgrade, and the replacement of the stock Campy's with new Boyd's, and original Arivas (my car only has 5,700 original miles), the balance of the car is completely stock. The carb (and intake manifold) upgrade I'm thinking about is primarily for reliability/drivability, but it would also be great to gain a little more HP.

Mike

Mike,

My advice is to first determine if your sputtering & dieing problem is fuel or ignition related. Fix that problem, and then make a plan to improve the performance of the motor.

Try to make the problem occur while the car sits in the driveway. If you can, you can then check for spark at the plugs. If you have spark, its a fuel problem, if you don't its an ignition problem. If you have spark, remove the air filter & look down the carburetor while someone else mashes the accelerator pedal. You should see fuel squirt from the accelerator pump. If you don't, your fuel bowls are empty. A new carburetor won't fix that problem.

Regardless of the low mileage, the car is 34 years old, and many of the parts will have aged just sitting.

Performance upgrades are a whole other topic, simply bolting on a carb & intake may not gain you one additional horsepower. The Autolite 4300D carb is a 700 CFM carb, and other than being jetted a little lean, it is not preventing the motor from making more bhp.

George