I was getting my 1961 exhaust manifolds ready for paint and the heat control valve on the left side manifold is shot. I cam probably get it to move again but the corrosion from rust is so bad I'm sure it won't seal. So now the big question. Is it worth finding a replacement, or just put a spacer in and be done with it? I'm in CA so not exactly a cold weather car, but I'd like it to run properly wherever I drive it so how critical is it? Anybody have experience running without one they can share?
I live in England and replaced it with a spacer on my 54 CDV many years ago with no detrimental affects.
Phil
One has to remember that when these cars were built, they had to be built to cover all and everything that the purchaser might be tempted to put the vehicle through.
The Heat Riser Valve (Butterfly) was put there to enable the vehicle to be started in any weather, from the Desert heat to the frozen North, and all the Butterfly did was to enhance engine warming up, and once the engine was at operating temperature, the valve was open.
Move forward to now, when these cars are being mollycoddled, there is no real reason for that Valve to be operating in the same way.
I remove them from my Exhaust Systems, as every car I have ever owned that had one, it was either frozen open, or had been gutted, or rusted away internally.
Bruce. >:D
I replaced the heat riser on my '49 with a spacer and have had no problems. I live in a southern state where winters are short.
Spacer or wire it in the open position.
Heat riser is not needed unless driving in Alaska in January.
Any suggested sources for a spacer?
I feel like $109 is a bit high for a 3/4" hunk of metal
https://www.caddydaddy.com/1955-1956-1957-1957-1958-1959-1960-1961-1962-1963-1964-cadillac-heat-riser-blank-spacer-reproduction-free-shipping-in-the-usa.html
When you get it you will be upset on the price. It is just a piece of laser cut plate steel. But around $100 is normal.
Quote from: Clewisiii on March 10, 2025, 05:57:51 PMWhen you get it you will be upset on the price. It is just a piece of laser cut plate steel. But around $100 is normal.
That's exactly what I'm expecting, both the product and the feeling
There is a laser cutter around the corner from me. I thought about trying to get him to cut a couple of dozen, and try to sell them for $50. But once I installed mine I didnt care anymore.
On my 54 there was enough play in the exhaust system to bolt it up without the spacer. Worth trying before spending $106!
Quote from: PHIL WHYTE CLC 14192 on March 11, 2025, 03:32:45 AMOn my 54 there was enough play in the exhaust system to bolt it up without the spacer. Worth trying before spending $106!
If you are fitting a factory-made exhaust, if you don't add the dummy piece, the whole system will be out of true. Or, actually being stressed when trying to tighten everything up.
Whenever I do any exhaust, I custom make them, so there is no need for the piece.
Bruce. >:D
I think I'm going to take my old valve to a machine shop and see what they can fabricate for less than $100. The studs on that side are longer and the threads under the spacer are rusted away so bolting up without a spacer isn't an option.
Have them hog out the butterfly and put a drop of weld where the flap pivot shaft goes. Now there will be no leaks. Install a factory sized piece and hook up your down pipe. You can do that yourself if you have a small welder. Your labor is as cheap as it gets.
I did what Big Fins did without the weld on my 55. I left the spring intact so I wouldn't lose points being judged. I live in southern Wisconsin and haven't noticed any problems even at temperatures in the low twenties.
Keep Cruzin,
Bob
Its been several years but I think when I ordered an exhaust from Waldron's for my 60 convertible we discussed not having a heat riser and they accommodated in the design and overall length.
I bought my spacer from a Studebaker site years ago. Same spacer and a lot cheaper
Mine has been stuck (open) fortunately since we got it.
Every once in a while I check yo be sure I have exhaust out of both sides to be sure it still is.
When the day comes that I drop the exhaust, my plan is to just remove the butterfly.
I was going to cut out the flap and seal the hole, but the body of the valve is so badly eroded by rust I'm sure it won't seal well. Maybe I can get a machine shop to take a little off the top and bottom, but for the same cost I can probably just get them to cut me a spacer. Not worried about points or judging I'm building this to drive.
I don't recall exactly how I did it, but I was able to remove the "blades" of the valve on my '60. The body and spring are still there, so it looks correct. I live in a pretty mild climate, but even on cooler days, I don't have any issues with warming up. I think the only real drawback would be if you are driving in conditions where you need full heat ASAP, like when these cars were daily drivers on cold winter mornings in the Midwest or New England etc.
The heat riser on my 69' was in really bad shape when I rebuilt the engine - seized, leaking. I told myself I never wanted to work on the exhaust again and spent the money on a new reproduction (I looked and don't remember being able to find a spacer for it as mine is beveled on one end). Anyways it works fine, but for what it's worth I don't notice any difference whatsoever and the new one actually seems to tick a tiny bit as well until it heats up. I also got some "Genuine GM Fluid 88862628 Rust Penetrant and Inhibitor" as recommended by site members as it's specifically made for the application.
The "tick" may well be an exhaust leak (gasket?), if so, it will get worse over time. Very typical for an exhaust leak to make a ticking noise and then go away as the metal expands as it heats up and closes off the leak.
I purchased a blank from Russ Austin for my 1964 Fleetwood to replace the valve, I also purchased blocked off intake gaskets from Olson gaskets for the exhaust cross over on the intake because my intake had a small crack in that area. Then i install an electric chock stat on the 4GC Rochester. When the engine goes back in after the dyno time I'm eager to see how well the chock performs with out intake heat @ warm up.