Carb Upgrade

[stevegintn]

A lot of convo about this on the conventional forum, don't see a lot here?

On my To-Do list for my 62 to upgrade the old Autolite 4100. what's your recommendation for a Holley or an Edelbrock?

Minimal re-engineering is desired (linkage, kickdown #@*'y, breather replacement, etc.)

[GeorgeG]

Steve: When I had to replace the old 4100 on my '61 I first went with an Edelbrock Performer 600 CFM. Much better than stock, but three problems. I never could quite get it dialed in; hooking up throttle linkage and kick-down were not really easy; and I couldn't use my stock TBird air cleaner (interference).

At the recommendation of several hot rodders here locally, I switched to a QuickFuel Slayer 600 with vacuum secondaries. Basically a Holley but infinitely more user friendly. Tuning was a snap. Throttle and kick-down hookup didn't require much thought. And, the best part, my stock air cleaner fit just fine.

With both of these carbs, I stuck with the stock intake manifold to keep the stock breather.

Oh, and with the Quick Fuel, I rerouted the stock down draft tube to hook into the carb directly with a really cheap PCV valve. Runs like silk.

I'm sure there are lots of other opinions on all this.

George

[stevegintn]

Steve: When I had to replace the old 4100 on my '61 I first went with an Edelbrock Performer 600 CFM. Much better than stock, but three problems. I never could quite get it dialed in; hooking up throttle linkage and kick-down were not really easy; and I couldn't use my stock TBird air cleaner (interference).

At the recommendation of several hot rodders here locally, I switched to a QuickFuel Slayer 600 with vacuum secondaries. Basically a Holley but infinitely more user friendly. Tuning was a snap. Throttle and kick-down hookup didn't require much thought. And, the best part, my stock air cleaner fit just fine.

With both of these carbs, I stuck with the stock intake manifold to keep the stock breather.

Oh, and with the Quick Fuel, I rerouted the stock down draft tube to hook into the carb directly with a really cheap PCV valve. Runs like silk.

I'm sure there are lots of other opinions on all this.

George

Thanks, George - but I have to ask, then why not just a Holley?

Can you share a photo or two of your setup?

Steve G.

[GeorgeG]

Here you go, Steve. Quick Fuel is an updated design of the Holley. A lot more user friendly and adjustable. See the sight glass to adjust floats. Started bys a bunch of Holley guys who broke off to do their own version for racing. Now they make models - like my Slayer - for road cars. Holley now sells them on their website. I got mine through Summit. Highly recommended.

George

[stevegintn]

Here you go, Steve. Quick Fuel is an updated design of the Holley. A lot more user friendly and adjustable. See the sight glass to adjust floats. Started bys a bunch of Holley guys who broke off to do their own version for racing. Now they make models - like my Slayer - for road cars. Holley now sells them on their website. I got mine through Summit. Highly recommended.

George

Awesome - many thanks, George!

I see that it appears all the linkage and kickdown assy hookup is the same as stock. And I believe you said, the stock breather fits it, as well? If you don't mind, what's the price tag for that puppy?

[GeorgeG]

The carb was about $340. And yes, the kickdown and throttle hookups were straightforward, and the stock vent tube and air cleaner work just fine. You can barely see it in my photo, but I drilled a hole in a leftover fuel line bracket and used that as the kickdown attachment to the base of the carb. The standard kickdown bracket could have worked but would have required a little grinding. The bracket I made works just fine and leaves the original intact in case I, or a future owner, ever wants to go back to the stock carb.

Only other minor issue was routing the fuel line. Fuel line comes up from the stock fuel pump on the driver's side and enters the carb on the passenger side (incidentally the same position as an Edelbrock carb). I also bought a fuel rail since I bought the version of the carb that uses a separate fuel input for the secondaries. I believe that QuickFuel has a single fuel line input version, so that's an option. I'm still fiddling with my hookup to make it prettier, but the way I have it now works just fine.

Oh yeah, and the electric choke. I had already made mods to provide 12 volts from the ignition switch to a Pertronix ignition system, so all the choke required was another hookup through a distribution block I had already installed on the firewall. You'd have to do something like that regardless of the carb type if you want an electric choke.

George

[stevegintn]

Thanks again, George - yes, the dual fuel input was a question, but I believe the QuickFuel model I saw online comes with a dual input fuel rail, installed? I will also look at the single input option. I had already put an electric choke on my old autolite (powered from the coil), so not a problem.

The only other question is, do I really need 750 cfm?

[GeorgeG]

Couple comments, Steve.

First, I used a 600 CFM carb because it was the same size as the original and my engine is basically stock.

Second, I was told that powering an electric choke off the coil was a big no-no. Not being an electrical guy, I'm not really sure why but that's why I went to the trouble to tap into the ignition switch wiring. This also gave me a real 12 v switched source that only works with the ignition on (not on ACC). Due to the stock resistance wire (the dreaded pink wire) running from the ignition switch to the coil, the actual voltage at the coil is only about 8 v, not 12 v. I needed the full 12 v switched for my Pertronix setup anyway, so the decison was a no-brainer.

George

[stevegintn]

OK, on the 600 vs 750 cfm - my bad - I went back and read where you said 600 (the QuickFuel ad I found was a 750). If I get one, I will go with 600.

So where did you tie into the ignition wire, at the coil, or somewhere else? (it would be ugly, but why not just come straight off the battery, since it's on the same side as the choke?)

[GeorgeG]

Steve. What you really want is a true 12 v switched source that is only active when the ignition switch is ON, not when the switch is OFF or on ACC. The only way I know to get that source is at the ignition switch. Off the C terminal at the back of the switch is a wire (mine is red) that is connected to the pink resistance wire (that sends ~8 v to the coil) with a bullet connector. I disconnected the bullet connector and built a short shunt wire from which I teed off a new (now 12 v switched) wire through a hole in the firewall. My new wire goes to a distribution block on the firewall because I needed 12 v switched sources for not only the choke but also my Pertronix coil. Hardest part is finding the connection behind the ignition switch. I had my dash apart, so it was relatively easy. I've been told though, that you can see the connection to the pink resistance wire from underneath the dash panel or (believe it or not) by pulling out the clock and looking back into the rats nest of wires.

I wish I had a picture, but I don't.

As an aside, if you have power windows, there's a relay on the firewall that gives you a true 12 v switched signal, but its on either when the ignition is ON or in the ACC position. Only problem with that is your electric choke will open if you're using the ACC to play music, etc.

George

[stevegintn]

As an aside, if you have power windows, there's a relay on the firewall that gives you a true 12 v switched signal, but its on either when the ignition is ON or in the ACC position. Only problem with that is your electric choke will open if you're using the ACC to play music, etc.

George

Understood. Which side of the firewall is that power window relay? (I would assume, driver's side)

[GeorgeG]

Steve. It's right next to the cover of the heater fan, sorta in the middle of the firewall. See below. I added the distribution block next to the relay for my 12 v distribution from the ignition switch.

George

[stevegintn]

Awesome - thanks again, George! I see that you ran the hot wire from the ignition to your dist block, instead of tapping into the pwr window relay.

So, all I need to do is tap into the hot wire on the pwr window relay, and I'm good to go, right?

[GeorgeG]

Awesome - thanks again, George! I see that you ran the hot wire from the ignition to your dist block, instead of tapping into the pwr window relay.

So, all I need to do is tap into the hot wire on the pwr window relay, and I'm good to go, right?

Yep. That's what I did first. Only thing you have to watch out for is that the power window relay is hot when the ignition switch is either ON or in ACC. So if you're listening to music or fiddling with the windows etc. with the ignition on ACC, your choke will magically open. My Pertronix ignition system doesn't like being powered without the engine running. That's why I went to the trouble of a separate 12 v setup that's only hot when the ignition is ON. But that's another story....

George

[stevegintn]

Yep. That's what I did first. Only thing you have to watch out for is that the power window relay is hot when the ignition switch is either ON or in ACC. So if you're listening to music or fiddling with the windows etc. with the ignition on ACC, your choke will magically open. My Pertronix ignition system doesn't like being powered without the engine running. That's why I went to the trouble of a separate 12 v setup that's only hot when the ignition is ON. But that's another story....

George

OK, well my radio is non-working, so not an issue Lol!

But a question about an electric choke - when it's electrified, does it start opening, without the engine running? - or, is it CAPABLE of opening, when the engine begins to warm up? (meaning, there's still an engine heat factor?)

If not and it's constantly ON (electrified), then it will stay ON (open), ALL THE TIME (i.e., no choking)?