Heat riser on L8

[Ornberg]

I guess the heat riser is stuck on my 1940 L8 engine. Can anyone tell me which direction should it rotate to open?  Clockwise or counterclockwise if looking from the front of engine?

Thanks

[GARY F]

I can't look at mine right now, but is the spring still hooked up. If it is it should be closed.. As it heats up the spring weakens and will open and go the other way.  If this helps.

[Ornberg]

Gary, unfortunately the spring is not there but thanks for your reply.

[Bloo]

If you post a picture of it I will make a guess. More or less, with the heavy part of the weight UP, the riser is in the cold-engine (closed) position. The weight will fall when warm, usually toward the block.

 

If you can't get an original spring, try some repro spring for a Buick or a Chevrolet or something. Usually they wind up a turn and a half or so (look at the manual for clues). If you can make it closed cold, and all the way open with the engine warmed up, it is probably close enough.

 

To free up a heat riser, get some of this, Mopar #4318039AC. It is oldschool heat riser solvent with a new name. Put it on every day for 3 or 4 days, and drive the car in-between to heat-cycle it. Then, tap lightly on the end of the shaft. Not in the direction of rotation, but side to side, both ways. If you don't see movement, keep soaking it and driving it a few more days and then try again. When you see it move, it is almost free.

 

Edited August 8, 2019 by Bloo (see edit history)