The Stovebolt Site Forums The Shop Area Engine Shop heat riser

I have a stuck heat riser on a 216. It is rusted in pretty good. I've soaked the shaft to manifold interface both inside and out with all sorts of stuff for almost a month now and no luck in getting it to move. I would like to remove the unit entirely and replace the shaft with a stainless steel piece and re-attach the weight and "butterfly" as well as machine the slot for the spring. I was wondering if any of you out there have done this "operation" before.

Try tapping firmly fore and aft on the shaft and weight. Keep the shaft wet with penetrating oil while you tap on it. You can hit pretty hard, but not like you are trying to drive the weight through the manifold. When the shaft moves a little, squirt more oil and tap in the other direction. Twisting the weight usually doesn't work until the whole thing begins moving. I haven't done the replacements you are thinking about, so no comment there.

Harvester

I've fabricated replacement parts on a few heat risers. The big problem is replacing the bi-metal spring, if it's weak or broken. Sometimes an automatic choke spring can be substituted. Don't make the shaft clearance too close, as it's an open invitation to rusting solid again if there's not at least a little slop in there.
Jerry

Most of the vendors have the spring.