The spring and weight on my exhaust maniford for the "heat riser" or control valve are missing. The engine heats up and after replacing the radiator, it still boils over in warm weather when going up inclines and after shutting the engine off. No, I don't overfill the radiator. The butterfly is movable. Do you have any suggestions other than , attach screw to butterfly and use a "choke cable" and do it manually.

Could that be a timing problem?

Are there any parts out there that you know of or ideas you might have?

Thanks, Jim Bob

 

I have a similar problem with my riser. I have yet attempted to get it free, but it is frozen 3/4 open and causes my truck to overheat after a two mile run. If I can get the manifolds separated I'm going to see about installing a plate between the two to block it off. It won't run well cold, but I expect it will be functional.

 

Why not get rid of it? The only reason I can see for keeping it, would be that your truck would warm up faster on a cold day. Were it working correctly, it would be full open once your truck was warmed up.

Michelle
Chelle's 56 Hauler

 

Remove the Butterfly or block it off, either way.....then, remove your thermostat. That way the engine will run cool.....jim

http://www.48f-1.com

1948 Restored Bonus Built Truck
1966 Ford Thunderbird

 

I need more to hear more before I remove the thermostat. Does your engine take a long time to heat up in Walla Walla if it ever does? jim bob

 

Jim,

I've always eliminated the heat riser in my cars as they are more trouble than they are worth. They always seem to freeze up at the wrong time. If you don't do a lot of cold weather driving, I'd eliminate it. So what if it take an extra couple of minutes to warm up to operating temperature?

As far as removal of the thermostat goes, it is usually a good idea to keep the thermostat. I've experimented and have had some vehicles that ran cooler without the thermostat, but I've had some that ran hotter so it's questionable as to whether it will help or not. If you remove it the coolant may not stay in the radiator long enough to cool down properly. The thermostat slows the circulation down to prevent that...

In addition, retarded or advanced timing can also cause an engine to run warmer than normal. I don't know if you have a shroud. Adding one may help, as well as using a fan with more blades or blades with more pitch...

Vern

 

I don't recommend removing the thermostat. My hot rod buddies swear by using one, or if removed, replacing it with a restrictor plate (same size as thermostat base with a 5/8" hole). This slows the flow like Vern said.

 

Vern, thanks for the great comments and what I call good "common sense" theory. see your note I made in BOLD. Since it is moveable I can put a weight on it or alternative to keep it "open" and see if it helps. Not sure how much force goes thru and why at higher speed it would want to divert hot air back to the carb unless it is off centered by weight or location (which it is in both situations, but not that much weight) and the flow from one side of the H226 manifold is greater than the other, etc. I just looked at the manual and the valve itself is weighted "down" to divert/block the rear two or three cyl exhaust but the counterweight (and spring which both are missing) is designed to open up the valve so by rotating the flap counter clockwise it should "open" the rear part of the manifold for unrestricted flow.

Anyway you have helped me greatly. back atya. Thanks, Jim Bob

 

Okay, at the moment I have the butterfly open since mine is broken. I have kept the thermostat in and with the combination of the two I have no problem the way I drive it.

Some old guy who used to work on these in a small town gas station told me about removing the thermostat. His theory was that the fluid would continually keep moving, thus cooling down the engine. He swore by it and I think I have even heard of that from other folks as well, possiblyon this board. The guy I bought my truck from was this same old guy and he had the truck when it was new!. When I bought it the thermostat was removed so it ran well for much of that time. As I was fixing some gaskets etc and had the radiator out, I noticed that there was no thermostat so placed one back in at that time. So it worked for him, might work for others although I haven't tried it much since having my truck (I've had it for 7 years).

I live in a fairly warm weather spot where it reaches 100 during the summer frequently and then gets way below freezing as well..... jim

http://www.48f-1.com
Restored 48 Bonus Built Truck
1966 Ford Thunderbird

 

I say replace your thermostat. They are cheap and easy to replace. A bad thermostat will cause your engine run ok during normal driving and overheat on hills if they are partially stuck open. Did you say that it only gets overheated when it is working hard going uphill? Also, you don't want to take the thermostat out all together, because your engine will take forever to warm up. And a cold engine does not operate efficiently so you mileage sucks (also your heater won't work). Even if the thermostat is new, it could be defective and causing the symptoms you describe. Let us know what the ultimate solution is. Good luck, John

 

Well, it has been a long time since we "talked". Left the St Louis area and moved to Williamsport, PA 4/'05 so it is colder. Replaced the thermostat last Nov but too cold to really check it out however hasn't overheated or boiled out after shutting it off but I haven't driven it 60 like before. Will let "youses" know when it gets warm here. That's Y'all to you Southern guys.

Jim Bob

 

My 51 226 has had a 160 degree thermostat in it and like you my exhaust heat valve weight and spring are missing. The only problem I have had with it overheating was when I replaced the thermostat there was some air trapped in the engine causing it to overheat. But other than that I have experienced no problem with it at all. The Flathead 6 cylinder engines have a inherent problem with head gasket sealing between the 3 and 4 cylinder due to head warping. If you are still having the heating problem after installing a new radiator I would look at another source. Maybe even take it to a radiator shop and have them do a test on the cooling system. I wouldn't remove the thermostat if I were you, the engine will probably overheat, or it could lead to the intake manifold freezing causing a dead spot off idle because the engine can't warm up the manifold properly if it's running too cold.
(I just saw that orginal post was from 2004 didn't see it before I replied)
Hope this helps
Rod 51F1

 

Rod 51F1, thanks, not gonna remove the thermostat. It had a new radiator in '98 so don't think that is part of the problem. Will wait until it get warm and see how it acts. Most info I have seen on posts help, especially guys like me that know a little but aren't "gifted" or full time mechanics. A good forum. Keep up the good work ! !
I joined as "Jim Bob" in '04 but when I moved to PA had missplaced name etc so rejoined rather than scrape thur boxes of stuff. Peace, Jim Bob