Heat Riser Valvle

[Brizio]

In which position it is closed?

[Sian09]

Should be closed with the rig off! The counter weight should be horizontal. It will move down, vertical, when the engine is warmed up, unless, the spring is warped, broken, or not functioning.

[Brizio]

Ok, I saw that also it move slowly. Which lubrificant I can use onit?

[Chevelleguy]

It is supposed to move slow, it opens as it heats up. I don't know of any lubricant that will withstand the exhaust temps.

[GWChris]

I have a tube of ultra high temp grease I got through the McMaster-Carr catalog years ago, and it works well on the heat riser. I just looked at their catalog on line and I cannot identify it, so I'll try to remember to look at it when I get home.

Lacking that, anti-seize works OK.

Getting it in there is another story. I have tried various methods, including glomming it all around the shaft and then blasting it in with compressed air and/or brake-clean.

[Menace]

The best thing to use on a heat riser valve (by far) is "GM Heat Valve Lubricant" spray part number #88862627. Most GM dealers stock it. This stuff works really good on rusted bolts too!

PS
If any one needs a new heat riser valve damper I have some brand new V8 Jeep units for $50.00 shipped, within the lower 48. Part #J3238998.

[djongeward]

Originally Posted by Sian09

Should be closed with the rig off! The counter weight should be horizontal. It will move down, vertical, when the engine is warmed up, unless, the spring is warped, broken, or not functioning.

Doesn't it stay open if the manifold is hot, regardless of whether or not the engine is on, or does it need the exhaust flow to keep it open?

During the latest rebuild, tear out, and clean up I removed mine and plugged the holes. I don't feel I need it down here in hot country, heck even my air cleaner cool air gate is open most of the time and my heat gate is closed.

[Menace]

If it's working properly it should stay open while hot, running or not.