Holley Carb Guru's - Boil over

[Joe C.]

Re: Holley Carb Guru's - Boil over

Keith

In addition to opening the heat riser & blocking off the hot-slot area -- which helps limit the convection heat source somewhat -- I would recommend dealing with the radiant heat generated by the intake runner(s) under the float bowls of the Holley, particularly when shut down & soaking is ongoing.

There's a Summit Racing aluminum heat-shield part that can be modified to present a dead air space between the intake runner & the float bowl. It needs few cuts, bends & a 'joggle', but works fine on my '66 base engine car. You can get an idea from photos, attached. Not sure what you'll run into obstruction wise on L36. I sandwich mine between two open Holley gaskets.

I doubt if those phenolic risers-things really do anything, since the conductive heat path is in the carb base, not the floats.

Jeff

They help immensely, as they retard the conduction of heat from the cast iron manifold, into the pot metal carburetor base. What they do NOT prevent is the convected heat from the hot air in the engine compartment to the pot metal carburetor, and the radiated heat from being absorbed by the carburetor's surface. Believe it or not, the best way to prevent radiated heat from being absorbed by the carburetor, is NOT to color it (leave it as clear pot metal), and give it a highly polished finish!

The only way to prevent the carburetor from being exposed to convected heat, would be to wrap it with insulation. This would not be fully effective unless the entire fuel line from fuel pump to float bowls is wrapped, as well. The mechanism at work here, is to keep the fuel at ambient air temp., so that it does not heat the well insulated float bowls.

[Keith B.]

Re: Holley Carb Guru's - Boil over

Thanks very much gentlemen, all excellent suggestions. I would like to try the insulated spacer but not convinced I have the room with my stock air cleaner and bubble hood. I'm going to measure though.........I have not plugged the cross over and was not aware of this...........thank-you. I will many of these steps............much appreciated.

[Gerard F.]

Re: Holley Carb Guru's - Boil over

Keith,

That heat shield thing noted by Jeff above, although not NCRS correct, sounds like a good deal. Might try it myself.

[Keith B.]

Re: Holley Carb Guru's - Boil over

Joe: Never heard of Quick Fuel, to be honest replacing my tired List Holley # 3370 is something I'm very seriously considering. After my L-36 rebuild, stepped up Sig Erson Cam, Engle valve train components, ported stock heads, etc, etc my engine I believe is screaming for more than 585 CFM from my 44 yr old Holley. Issue I have as you likely know is most 750-850 CFM carbs like the Barry Grant's have 1 11/16 throttle blades as do most then it does not fit my GM stock cast iron bores on my intake, then where do you stop or go from there on a TF car. I know the L-72 had a larger carb and then in 67 on the BB they were allot more air flow from an L-36 585 4 barrel. I imagine Quick fuel all use 1 11/16 throttle blades also, not trying to build a race car but there are limitations with these old Holley's and today's gasoline, etc..............

[Keith B.]

Re: Holley Carb Guru's - Boil over

Joe: Never heard of Quick Fuel, to be honest replacing my tired List Holley # 3370 is something I'm very seriously considering. After my L-36 rebuild, stepped up Sig Erson Cam, Engle valve train components, ported stock heads, etc, etc my engine I believe is screaming for more than 585 CFM from my 44 yr old Holley. Issue I have as you likely know is most 750-850 CFM carbs like the Barry Grant's have 1 11/16 throttle blades as do most then it does not fit my GM stock cast iron bores on my intake, then where do you stop or go from there on a TF car. I know the L-72 had a larger carb and then in 67 on the BB cars there was allot more air flow than an L-36 585 cfm 4 barrel. Can we say Tri-power. I imagine Quick fuel all use 1 11/16 throttle blades also, not trying to build a race car but there are limitations with these old Holley's and today's gasoline, etc..............

[Clem Z.]

Re: Holley Carb Guru's - Boil over

here is the holley heat shield that can be cut to fit. http://webcache.googleusercontent.co...&ct=clnk&gl=us

[Ronald L.]

Re: Holley Carb Guru's - Boil over

Keith, What ever you do save the 3370, just put it in a box for the day you want to judge the car. There was a leaking problem with these carbs, the 66 I have now had a perforated plate and it was a flood of gas. The carb sits restored in a box, ready to bolt on.

Then I ask those that got these cars new, was there a percolation problem in 1966, 70? I sure don't recall one on my 70, nor any car fro that matter in the 70's and 80's.

Back then when gas shot up to 75 cents a gallon for the Sunoco premium, and filling up my 66 people would ask how much does it cost you to fill it up. I know many have heard the answer... if you have to ask, you can't afford the car.

The same might apply today...

How much do you drive the car? 500 miles per year? Mine gets 9 - 10 miles per gallon with a larger-old Holley 800 on the 427, so say 50 gallons a year. So at 500 miles per year your total gasoline costs are: Regular 93 ROH gas $175, Sunoco blue 110 $325.

$150 will get lost in the background noise of insurance and everything else we do with these toys

I'm open ears on the quick fuel carb just to have a better daily runner, but in the end why go through these work arounds if better fuel fixes the situation.

[Joe C.]

Re: Holley Carb Guru's - Boil over

In case anyone is interested, which I seriously doubt:

http://www.quickfueltechnology.com/

Perhaps it will be "comforting" for all of you more, shall we say, obsessive types, that Quick Fuel is located in Bowling Green, KY, a mere stone's throw away from the NCM and Corvette Assembly plant.

If you drive your Corvette, rather than just stare at it, then you owe it to yourself to remove that POS Holley and replace it with a bulletproof, state of the art carburetor.

If you don't want a "race" carburetor, then look at the SS or HR series. These "replacement" carburetors are light years ahead of Holley as far as performance, quality, and advancement are concerned.

If you'd rather not put a nice, shiny carburetor on your engine, since it is just too darn "incorrect", then go with the more correct heat shield, and wrap the carb in reflective material, like aluminum foil. Make sure that the more reflective side faces away from the carburetor.

[Timothy B.]

Re: Holley Carb Guru's - Boil over

Just my opinion, nothing wrong with the holley.. Plug the hot slot holes and set the inital timing at 12*. Make sure the VAC is working properly and let us know the results because you may be surprised..

[Ronald L.]

Re: Holley Carb Guru's - Boil over

I have my original L36 intake plugged as per above, getting ready to put it back on.

I know what AIM says, but people have moved on in attempts to stop fuel boil out.

What is the correct order - combination of gaskets, metal shield?

Should a gasket be on both sides of the shield?

[Clem Z.]

Re: Holley Carb Guru's - Boil over

I have my original L36 intake plugged as per above, getting ready to put it back on.

I know what AIM says, but people have moved on in attempts to stop fuel boil out.

What is the correct order - combination of gaskets, metal shield?

Should a gasket be on both sides of the shield?

manifold gasket then stainless steel plate. i would put a carb gasket between the carb and the stainless steel plate to make sure you have no vacuum leaks. unless the throttlr base plate on your carb has been machined flat it most likely will be warped

[Ronald L.]

Re: Holley Carb Guru's - Boil over

Clem, Thank you so much for the fast reply, that is what I was thinking and just got that extra gasket, along side the OE style thermostat that opens 20 degrees hotter that it should.

[Tim S.]

Re: Holley Carb Guru's - Boil over

I have heard nothing but great reviews from this fellow. He does quite a bit of resto work in addition to help compliment performance mods

http://www.vintagemusclecarparts.com/

Once I put away my LT-1, I am sending my carb to him.

[Ronald L.]

Re: Holley Carb Guru's - Boil over

Tim, That is who I used, bolted on the current configured engine, one push of the pedal and it ran, no adjustments were really required.