Re: Carburetor Heat Shield

Posted by Fish'n Jim On 2020/9/4 19:48:02

I don't think it uncommon with today's ethanol gas that people have been observing bubbling in the fuel bowls. Gasoline composition changed quite a bit since '49. I've compared specifications in the past, maybe on here(?). Plenty of info on effects of ethanol on boiling curve. But has to be fairly hot to do that.
First I'd check/tighten the fittings to make sure no air bleed, and try non-ethanol gas, if available in your area.
Never hurts to isolate carb(s) from a manifold such as this which has both intake/exhaust temperatures. I just went through this precautionary exercise on my modified Cad which has a central runner for exhaust based on erroneous understanding of the day.
My '49 the fuel bowl is immediately forward of the carb. And there's wide open spaces, so I didn't observe any issue with it idling for long periods, but others complain. It idles at ~400 rpm.
It's imperative to make sure all the inner panels are installed to direct the air flow through the radiator so the fan does it's job. Autos are air side controlling.
You don't mention if you did anything to the radiator, perhaps it's in need of attention. A infrared camera scan will tell.
Ernie is correct, no need for high test in a low compression motor. I'd argue the mystery oil add but I like to argue. Why would anyone use anything that's a "mystery" ie, not knowing what it is, is a mystery to me... I'm not as trusting.