What is this port on an electric choke housing?

[freejak]

I recently replaced the quadrajet on my 1966 Tempest Sprint. The original carb used a divorced choke. The replacement has an electric choke. The change went smoothly.

I have a question though. There is a small tube projecting from the front of the electric choke housing and I would like to know what it's purpose is.

This appears to be open, but I didn't try to verify that. I did not want to poke anything in not knowing what might be 'waiting' inside.

https://drive.google.com/open?id=13mHDeL5oYqGw0A0lRcWPf3zLcnf2Zab8

https://drive.google.com/open?id=1EuWATwyCcPT0TKpFR79VMoYpm0gggvil

P.S. Is it possible to embed an image right here in the forum? I couldn't figure out how to get the image tags to work.

Thanks, Jack

[Frank400]

If the port you are referring to is open, the choke housing you have is from a "hot air choke" carb (pre-1980).  I have seen some 80 and up electric choke carbs with the same housing, although it was blocked.  Either way you are fine, if it's open, I would shut it but if you don't no big deal.

[Cliff Ruggles]

Once converted to E-choke doesn't matter if there are openings for the original hot-air tubes as the vacuum supply should have been plugged internally.

The carb has the wrong fuel filter housing on it, those take a short one and long filter inside the carb.  I would get rid of the external filter and rubber hoses that's a disaster waiting to happen.

At a minimum put "bulges on the metal fuel lines and clamp behind them so the hoses can't slide off the metal lines if you hit a bump or get in a fender bender.

There really should be solid metal lines on the pressure side of the pump and the filter moved inside the carb, just like GM did after burning up some good folks back in the 1960's with those set-ups......Cliff

[freejak]

I replaced the fuel filter housing in order to mate the existing 1/2" 20 fitting on the fuel line with the 1" 20 inlet on the new carb.

I have hunted high and low for a short fuel fitting that is (what I believe to be) the 'new' 1" 20 on the carb side with the 'old' 1/2" 20 fitting on the fuel line. I also have looked for a 5/8" 18 to 1/2" 20 converter fitting without finding anything.

If you've got a line on either, I'd love to hear about it.

What I could find was the long fitting that's in place now as the best existing option. The long in-carb filter is still in place. Is this a performance/safety concern?

I am looking at engine bay fuel plumbing in general and will eliminate the external filter and rubber fuel lines asap. I appreciate you pointing out the safety concerns.

Thank you for sharing your expertise.

Jack

[Cliff Ruggles]

External filters on the pressure side with rubber hose and clamps are not a good thing in this hobby.  Even worse is that 99.9 percent of them are not used with "bulges" on the metal lines so the clamps make it impossible for the hose to slip off the steel tubing.

At a minimum make sure there are "bulges" on the metal lines and keep a close eye on the rubber hose, it deteriorates quickly with this new fuel going thru it.

We use a short piece on our test engine from the regulator to the carb so we can test carburetors.  It's the latest stuff from NAPA and rated to be good with ethanol.  Even so it starts to break down and flake off pieces of material in about a year.  It also gets hard/brittle and cracks on the outside, so we replace it frequently.

Didn't completely follow all the sizes stuff above but if you are trying to find a 1"-20 fitting for 5/16" inverted flare lines they don't make one.  The cure would be to move up to 3/8" lines.

The later type long filter will work in the longer housing but the stock type spring will be too short so you'll need to use a longer one to keep it seated.

That would be easier than using the correct short housing converted to NPT threads with an adapter to 5/16" inverted flare.....IMHO.

PS:  where did the carb come from?  It looks like a lot of them that I get from the left Coast.......Cliff

[freejak]

Hi Cliff, Thank for the additional information.

I got the rebuilt carb from I-Five Components, they're in Moreno Valley, CA.

Jack

[Cliff Ruggles]

I hope it works well for you.  EVERYTHING I've ever had sent here from that source was a complete DISASTER at every level!........Cliff