Anyone have any info on this radiator cap? At first I thought it whistled, but on the inside it has a spring with a cup with rubber on it, so as you tighten the top nut it puts more pressure on the hole on the bottom of the cap. Is this meant to steam as you go down the road? Any info would be great.
Here are some pictures of it polished up and on my 15 touring. When I drive it I guess I will find out exactly what it does.
I don't know it's function but, I wish it was mine.
Mike, haha it is a really neat cap, cant wait to find out what it does...and John, thanks very much! Not sure if I love the looks of this cap on my car over the original, but its certainly a conversation piece.
I hope it blows smoke-rings at idle, now that would be cool
I bet it whistles when she gets all steamed up! Wonder what is missing on top?
Mark, its not missing anything, the thread is actually a screw that screws down when you turn the nut at the top. When it screws down it puts pressure on a cup cup with a rubber pad on it that presses down over the hole at the bottom which must turn off whatever it does. I have it screwed up because I am assuming that is the "on" position. Ive never seen another cap like this.
Well, what are you waiting for, there are 24 hours in every day and you have headlights, let her rip. The anticipation is killing most of us, well maybe not.
Andy, I really want to, but its been raining very heavily for the past few days here in CT so I have to pait until the weather subsides . I could let her sit and idle, but what fun would that be?
Hey, I know! It's like one of those manifold cookers. It's a pressure cooker. Is there also a round little weight that bounces around and let's out steam while your cooking cabbage and ham?
Or a tea pot.
Sounds like it may be some sort of pressure cap with adjustable pressure, but you would have to plug the overflow for any pressure to build. I know Jay has a lot on his mind right now, but when he is up to it, I bet he knows what it is.
My guess is that it is like a pressure cooker, too much pressure and it blows off. If it made a tone or a whistle, it would be sweet thing to never hear
My first impression was that it looked like a pressure regulator. Similar things are used on water lines or even an acetylene torch.
Hal, thanks for the input. I will try and block off the overflow pipe when I test it out to see what happens. What would be the purpose of an adjustable pressure cap?
To keep your unnecessary water pump from cavitating.
Why don't you bench test it on an old black radiator or hook it up to an airline with a low pressure regulator? Pressure testing it with a nice $1200 brass radiator doesn't seem like a good idea to me.
I did put an air hose up to the bottom of it and all it did was blow the air out of the holes. I don't know how much damage this cap could really do. If I close it up, then there might be some sort of an issue. Im going to run the car without closing up the overflow pipe first to see if it does anything that way, because the radiator still builds up steam and pressure.
It needs to be closed tightly or you will have water droplets going all over your paint and brass.
I wouldn't plug the overflow until I knew for sure what the cap's purpose was. Modern radiators run at pressure to basically raise the boiling point of water so that boiling never takes place unless something is really wrong. I'm not sure why a T would need this. I was only speculating, as that is what it looks like it was intended to do. Why? I don't know that I can answer that one.
Modern radiators don't have as many large flat surfaces as a T radiator does. While I don't believe pressure would hurt the core, it could certainly deform any flat surfaces in the tank area. I wouldn't pressurize a T system.
Is the cap heavy?
In use on a bumpy road it might crack the radiator neck or disconnect it from the upper tank if it has enough weight.
Blow in it! I'm with the folks thinking it's a really cool whistle.
Super nice car.
I think it's a whistle, but I don't know a thing about T's, just like to look at them.
Very nice radiator cap. Does it whistle as the water is near to cooking??
Living not far from Brussels I have special one to.
Mine need to go to the loo sometimes.... .
an other photo
I was looking at it and I am going to guess that as the T gets warmed up it produces steam, so I am going to guess that this thing works kind of like a tea kettle, when it gets to a certain point, it blows enough steam to make this thing whistle. I think this cap transforms you car into a Model Tea Pot. The steam builds in a large surface only to have a small hole to go out of. Here is a description of how a tea pot works:
Their results showed that, above a particular flow speed, the sound itself is produced by small vortices – regions of swirling flow – which at certain frequencies can produce noise.
As steam comes up the kettle’s spout, it meets a hole at the start of the whistle, which is much narrower than the spout itself. This contracts the flow of steam as it enters the whistle and creates a jet of steam passing through it. The steam jet is naturally unstable, like the jet of water from a garden hose that starts to break into droplets after it has travelled a certain distance. As a result, by the time it reaches the end of the whistle, the jet of steam is no longer a pure column, but slightly disturbed.
These instabilities cannot escape perfectly from the whistle and as they hit the second whistle wall, they form a small pressure pulse. This pulse causes the steam to form vortices as it exits the whistle. These vortices produce sound waves, creating the comforting noise that heralds a forthcoming cup of tea.
how kettle whistles
This diagram shows the mechanism by which a teapot whistles. (Image source: Cambridge University)
So why a whistle compared to another noise? This is determined by the length of the spout and size and shape of the opening.
The other mechanism discovered is that sound is also produced differently when the kettle comes to a boil. The researchers describe this mechanism as similar to the sound made when blowing over a bottle.
“In a kettle, of course, the air is blown through, rather than over, the neck – the effect is similar to whistling by mouth,” Henrywood said. “In some kettles, both these mechanisms are happening. Because our study enables us to assess the mechanisms in action, we can potentially make modifications to stop the noise – if we want to.”
And there you have it. That’s how the teapot got its “shout.”
Forgot the diagram.
It is a probably a pressure release valve, Ive seen very similar including the holes on the side hooked inline to old free standing heating radiators. I would not use it unless I knew what it was. I would not run it until I knew exactly what it will do under pressure. It may be dangerous, and all you need is for it to go off while some kid is closely examining it while parked, especially when there is no telling which way the scalding water may spray.
I would think, based on the look of the rest of his car, that he will have to run with the spark retarded intentionally to get that T to overheat and do anything with the cap. Regular steam produced from normal operation isn't going to make any noise unless the spring is almost non-existant. You can drive with the cap off with no problem and the only thing you are losing is a tiny bit of steam (or maybe some will slosh out on a big bump).
Ed, you may be right. But what would be the purpose of such an odd bell shape with six holes in the style of a dog bone cap for a Model T if it is simply just a pressure release? Maybe this was a quick fix for cars that had overheating problems, so instead of throwing water everywhere it would release the pressure before that could happen? And Seth, I would rather put this thing on my shelf than run my car retarded to get it to overheat haha, but even then I don't think this car would get hot.
I researched radiator alarms and radiator whistles in Google books and found a few examples from the early 1920s - hopefully these links work:
http://books.google.com/books?id=gyoDAAAAMBAJ&pg=PA68&dq=radiator+alarm&hl=en&sa =X&ei=d5nGU5OTD4y1yASom4LAAQ&ved=0CDEQ6AEwATgK#v=onepage&q=radiator%20alarm&f=fa lse
http://books.google.com/books?id=StoDAAAAMBAJ&pg=PA673&dq=radiator+whistle&hl=en &sa=X&ei=_5nGU_-JK420yATrzICwDA&ved=0CE0Q6AEwBw#v=onepage&q=radiator%20whistle&f =false
http://books.google.com/books?id=oCoDAAAAMBAJ&pg=PA77&dq=radiator+whistle&hl=en& sa=X&ei=TZrGU9fmL4ObyATd2YKoAw&ved=0CCsQ6AEwADgK#v=onepage&q=radiator%20whistle& f=false
http://books.google.com/books?id=GOIDAAAAMBAJ&pg=PA795&dq=radiator+whistle&hl=en &sa=X&ei=TZrGU9fmL4ObyATd2YKoAw&ved=0CDcQ6AEwAjgK#v=onepage&q=radiator%20whistle &f=false
I shouldn't say "researched." Actually, I only searched.
I would not fear this curious thing... My Dad once described seeing and hearing whistling caps on old cars when he was a kid (he was born in 1908). I thought he was pulling my leg... but it appears you just might have one!
Maybe Art could find patent info for it?
Well, I drove the 15 to work today with the cap on it and the cap didn't really do anything , but again if anyone finds out exactly this caps purpose, I would love to know. Thanks!