Hot Air Choke Conversion

Hot Air Choke Conversion

Joined: June 23rd, 2010, 6:12 pm

June 23rd, 2010, 6:16 pm #1

Howdy. Nice Forum.

I have a Autolite 4100 with hot air choke.

If I convert it over to electric, what happens with the air draw passageways? Do these get blocked off? Does the carb still get air from the passages? Does blocking them change the A/F ratio? You can't leave the passage open can you?

I'm sure its been figured out before but noone seems to know.

Thanks.
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Joined: June 23rd, 2010, 6:12 pm

June 24th, 2010, 1:22 am #2

Did some more searching. Let me see if I got this right.

The Autolite 4100 pre-64 reportedly can use Holley jets and be more "tuneable", does not use material that'll degrade by alcohol in gas in the accelerator pump or booster. Good things right?

Downside reportedly is the longsnout, as here, has a pulloff less good than the shortsnout, right?

Most all 4100s had the hot air choke assembly. Few had manual. None had electric. Conversion over to electric requires closing off the internal vacuum so as to not suck air.

So if I'm not worried about numbers matching, a perfectly restored pre-64 longsnout 4100 like mine will work best with a hot air choke or an electric conversion if hard pressed.

Does all this assessment of the 4100 for a 300hp Ford 289 sound right?

Where am I wrong? Thanks guys. Be gentle.
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Lee
Lee

June 24th, 2010, 4:05 pm #3

to have air drawn in from the choke housing, so you can just leave that system intact by routing a hose from the air horn fitting(filtered air) to the choke's hot air intake. This'll preserve the original A/F ratio as it was specced with the primary booster configuration. Don't know about diaphram materials being unaffected by the alky in fuel...new to me. Holley jets fitting?...a good thing indeed.
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Cougarrrman
Cougarrrman

July 6th, 2010, 9:31 pm #4

I did the conversion, rather simple but not a "bolt on".
I used a Holley electric choke http://www.summitracing.com/parts/HLY-45-258/
Outside diameter of the Holley part must be turned down to fit the 4100, I believe about .060"
The "tang" that goes inside the bi-metal coil must be shortened somewhat, the Holley part is not as deep as the Autolite.

I simply made a 1/4" tubing bypass so clean air would be drawn through the choke coil.

Works great! My Stealth intake had no provisions for the heat coil (460) and I blocked the crossover heat.
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