Holley Carb rot - Quick Fuel carbs

[Mark23T]

My dual Holley 450's are rotting from the inside out! Went through both carbs when I bought the car less than a year ago as it had been sitting and they weren't happy. I ended up replacing a metering block and two float bowls because the plating or finish on them was coming off inside. Less than 1000 miles later and it plugged up again. When I tore them down the other metering block had "peeled" and none of the float bowls looked "great". There was some corrosion in all of them.

I'm assuming it's the ethanol in California gas doing it? I ran a lot of Holleys in the days before ethanol and never had these issues. Short term, I'm replacing parts and will run an ethanol treatment (like I put in my garden tools to keep them from clogging up all the time) in hopes that the carbs will stop eating themselves up. Has anyone ever been through this? Is there a cure?

Long term I guess I'm looking at replacing the carbs. My local carb guy suggested "Quick Fuels" as they don't have the same type of plating as Holleys, they have billet metering blocks, etc... The price is right ($700 a pair), but I'd been told by a trusted source prior to this that Quick Fuels were "junk". Not a lot of other options out there as I don't want to lose my polished tunnel ram and anything larger than 450's is liable to drown my little 350.

My present carbs are mechanical secondaries, but the Quick Fuels are vacuum. Not sure if that's going to be an issue...

Has anyone run a pair of Quick Fuel 450's? What's the good/bad?

Thanks in advance!

 

[Spanky]

I feel your pain, Mark. No problems with my Demon carb yet, but I treat every tank of gas with a product called Pri-G. 'Been on the road for four years now without issues, but I know the ethanol-laced gasoline is like a ticking time bomb. No experience with Quick Fuel's, but I can forsee no problems with vacuum secondaries on your tunnel ram setup. Just sayin' . . .

 

[409T]

I have a pair of 600 cfm Quick Fuel vacuum secondary carbs on a modified tunnel ram sitting on a nearly stock 327 in a T-bucket. You can stomp on it as hard as you want from a standing stop and there is absolutely no hesitation.

 

[rbsWELDER]

I have been using Seafoam and I have been very happy with it.

 

[Indycars]

Is pure 100% gasoline not available in every state ?

That's all I run, except a few times a year when I'm on the road and don't want to
go looking around. I'm running a Speed Demon carburetor without any problems.

 

[Mark23T]

I have a pair of 600 cfm Quick Fuel vacuum secondary carbs on a modified tunnel ram sitting on a nearly stock 327 in a T-bucket. You can stomp on it as hard as you want from a standing stop and there is absolutely no hesitation.

That's good to know. I really didn't think that was doable. Did you have to do a lot of jetting & adjustments, or did the 327 like them right out of the box?

 

[Mark23T]

Is pure 100% gasoline not available in every state ?

That's all I run, except a few times a year when I'm on the road and don't want to
go looking around. I'm running a Speed Demon carburetor without any problems.

It's not available here! Hence my comment about the additive that I put in my garden tool fuel. Didn't matter if it was 2 stroke or 4 stroke, if the carb sat without fuel moving through it for more than a couple of weeks, it would clog up. Those little fuel primer bulbs? Six months max before they'd split. Adding "ethanol shield" to the gas cans has helped a ton.

 

[409T]

That's good to know. I really didn't think that was doable. Did you have to do a lot of jetting & adjustments, or did the 327 like them right out of the box?

I bolted them on and didn't change a thing, but they came tuned for the manifold that I bought as well.

 

[choppinczech]

The Quick Fuel HR-Series 450 has mechanical secondaries.

 

[rbsWELDER]

There is a great phone app, called "pure Gas" to help you find ethanol free gas. I use it mostly when I am out of town. My runs on my Android phone.

 

[Mark23T]

Well, this story had a happy ending after all. I had several car club members as well as a couple of racer recommend "The Carb Shop" in Ontario, CA. I filled out a 5 page "calibration form" online that gave them everything they needed to know about the car and motor. Cam specs, head & manifold specs, gears, ignition timing, converter, shift points, tire diameter, etc... Without ever seeing the car, they handed my 450's back and they're PERFECT. I didn't even have to set the idle speed! Purrs around town like a new car and I can stand on it at any point and it goes like it was shot out of a cannon. It even sounds like a totally different car.

After all of the assumptions and advice I had received on the ethanol eating the carbs, it turned out that they had both bad metering block castings and bowl plating. The metering blocks were basically "crumbling" (damage wasn't visible by simply looking at them) and was plugging up passages in the main bodies and the bowl plating was basically defective. Apparently a known problem from the time frame mine were made. They replaced the blocks and glass beaded the plating off the inside of the bowls and told me not to worry about fuel additives. Those problems were solved for good.

Not cheap. Their "Stage 2" calibration included:

• Machining of body and base plate surfaces.
• Sizing all the fuel and air passages to factory specifications.
• Checking and correcting metering blocks to ensure a flat surface.
• Re-assembly with new floats, needle and seats, and non-stick gaskets
• Testing on DTS engine Dyno.
• Verification of fuel curve and calibration.
• Calibration of the fuel curve in the metering blocks' emulsion circuits.
• Installation of and alignment of correct style boosters to match engine combination and usage.
• Installation of correct idle air bleeds and high-speed air bleeds.
• Machining for four corner idle circuit to engine's requirements.
  
  Dollar for dollar, the best performance investment I've made to date!

 

[Intrepid]

Nice to have a place like that around.
I am hoping that's Ontario Canada but I am assuming it is Ontario California.

 

[Mark23T]

Nice to have a place like that around.
I am hoping that's Ontario Canada but I am assuming it is Ontario California.

Yes, sorry... Ontario California