Re: Heat Riser problem

Posted by BH On 2007/8/16 8:32:53

The latest issue of Hemmings Classic Car that arrived in my mailbox has a feature on the development of the Rochester mechanical fuel injection system (1957). One of many things they had to take in account was that at 60^F, there was only something like 50% vaporization of gas. This important because only vaporized gas burns - the rest gets wasted.

As such, in a carbureted car the manifold heat valve is very important to performance during warm-up.

My father worked as a mechanic in a Packard dealership, but when the dealer switched to Chrysler product (when the Studepackards came out), my dad moved on to a Chevy dealer, where he soon became Service Manager. He swore by a chemical supplied by GM as (IIRC) "Manifold Heat Valve Lubricant", which is still available through GM dealers under the same part number (#1052627), but now called "Rust Penetrant and Inhibitor", with "Heat Valve Lubricant" as subtitle on the can.

If that doesn't free the valve up, then it may be "hammer-time".