VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 35 heat riser

I have a 35 Standard Coupe with a stuck heat riser, although I don't know for sure which position it is stuck in, heating the intake or straight out. The end of the shaft that is visible to the outside, with the bimetallic coil, has a slot that is vertical. I have noticed that my engine runs fairly warm, especially when there is not a lot of airflow through the radiator. If the riser is stuck in the heating position, am I looking at an impossible job to get the intake and exhaust manifolds separated from each other ?

Mike, I have a 33 master w/ the 206. I actually have the manifold off the truck now and my heat riser is also stuck in the straight out position, which is fine cause I don't drive it in the winter. At least that is what I was told. I dont know if you can see in the back of the intake, but mine has a spring which appears to hold the damper in the open position. That spring should be horizontal and would be about 45 degrees if it were closed. the shaft sticking out on the coil side on mine is a round shaft, hollow, and has a slot in it which is facing almost straight down. the numbers on the manifold are 836919. Hope it helps. I can send you a picture if you want.
David

Mike,
I also have a '35 Standard coupe. My current project, however, is a 1936 truck. I had no trouble separating the manifolds for the truck. My head gasket set included a new gasket. It might be a little difficult to find by itself but you could make it if you had some suitable material.
I would like to make new stainless parts for the heat riser but I am sorta wishing I had not taken it apart.

Mike

I just looked at the riser now, and on the side facing out, the slot on the end of the shaft is vertical. On the side toward the engine, there is a small spring, but it is only hooked to the manifold at one end, the other end hangs free. The counter weight on the shaft appears to be mounted to a short arm at the end of the shaft, and this armm seems to be horizontal, with the weight at the front end. Does this match up with what you have? And if so, does that mean it is stuck in the cold weather or warm weather position. If it is stuck in the warm weather position, I think I'll just leave it for now, don't drive it much in the cold.
Thanks for the quick response. Mike

Mike,

Assuming that your's is similar to my 1933, I checked my photos from when I fixed my frozen riser, and when the slot in the shaft is vertical, the riser is in the bypass position (i.e. not sending hot gases toward the intake/carburetor.

Mark

thanks for the info. From what you guys have told me and looking at the workshop manual, I think my heat riser is stuck in the warm running position, so if there are no other problems, I am going to leave it alone for now.

My riser is missing, were do I find parts, or, could anyone you give me dim. and a picture?

Look under your "My Stuff" at the top of the page. I sent you a PM.

Guys,
In most instances it doesn't matter what position the shaft is in. The butterfly (flap) and the shaft are made of carbon steel and both corroded quickly in the exhaust stream. Replacement with stainless materials is the best way. Since I'm not a machinist, and I only drive the car in warmer weather, I put a solid piece of steel reinforced gasket material to blank off the heat from the carb. Yes, the engine stumbles a bit until warmed up but I can live with that.

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