No heat at the automatic choke

[Calvin M.]

Re: No heat at the automatic choke

Here's some shots of the replacement and original manifold heat tube from my '57.

The original is indented lengthwise on three sides, leaving a fairly small triangular cross section. The replacement only has one pressed in area, about a 1/2" long, as you can see in the pic. (The clevis pin to the left was my 'installation tool')

[Stuart F.]

Re: No heat at the automatic choke

Calvin;

What you show is more like what I remember the heat tube looking like. Thanks. Guess I wasn't going crazy after all. Now then, one can only speculate as to when and/or why/or if the design was changed, and if so, could this be the source of choke problems others are having with at least the C-2's?

Stu Fox

[Calvin M.]

Re: No heat at the automatic choke

I think you're right, Stu.

I scrounged around and found the heat tube pictured before, but got a better cross section shot vs. the end of the tube which is more representative of the entire length of the replacements (except for the 1/2" pressed in portion).

The original tube appears far more restrictive.

Cal

[Stuart F.]

Re: No heat at the automatic choke

Cal;

Great pictures.

Thanks.

Stu Fox

[Timothy B.]

Re: No heat at the automatic choke

Hi Cal,

Thanks for the pictures of the tube showing the restriction to air flow. My memory tells me the tube I removed from the 902 manifold on my 63 had no such restriction. The new tube that's installed looks exactly like your replacement part.

This is interesting to me because if I block the air flow in this hot air circuit my engine rpm slows approx 100 +-. I described my problem above in a post and that's got me stumped, this condition could contribute to the issue I am working on.