Re: Replacement/Aftermarket Carb?
I'd agree that there may not be a good reason to shelve what you have. However, for general street purposes you'd prbly be better off in the 650 cfm realm for improved thottle response.
As for Quick Fuel - I recently replaced my 670 Holley Avenger with a Quick Fuel 680 Vac Sec. HR series. At first I was very impressed with all the added features, aluminum parts, etc. but has been extremely finicky to dial this carb in. I've never experienced such a battle with getting a carb dialed in properly for all aspects of fuel delivery. After about 2 months of experimenting (here and there as I can on wknds) and calling Quick Fuel techs who I've found will advise contradictory to each other (which is fine and typical in the industry but providing 100% opposite solutions for a basic questions, make me wonder and have since moved on to other sources cause I feel like I'm rolling the dice with reps on their ph. lines).
I've recently discovered that the linkage that activates the pump arm is chinsy and bends quite easily compared to a Holley. A few other basic linkage/parts are inferior as well when comparing side by side.
It will idle fine most of the time and intermittently changes idle speed by as muich as 200 rpm on me (I have no vaccum leaks, ignition issues or other problems). The choke does not operate consistently/reliably either so disconnected it. Cooler temps. drastically impact fuel to point of running fine at 75 deg. ambient and barely running decent enough to drive at 45 deg. ambient. I have a wideband so can pay close attention to how it's delivering fuel as well. Never seen that w/Holley's or Edelbrocks. Now that I've lived with this carb for a couple months, I would have paid more $ for a Holley of equivalent features cause I've never had issues with numerous Holleys (or Edelbrocks) over the years. The seconday plate was not adjusted properly from the factory (a very important essential of basic out of box functionality) and wasn't until recently that a tech pointed me in that direction as the possible cause of my tip in lean issues that still refuse to go away. It has some nice features and price is good compared to Holley but it's not quite the value that I thought it would be. I may have gotten a dud. I will say that under full throttle pedal mashing, it is doing well but I feel like I've lost significant ground when comes to reliable street manners. So I'm now thinking about putting this new one on the shelf cause the speed shop won't take it back.
Last edited by 68RS-SS; Nov 20th, 12 at 02:00 PM.