See the heat


2 replies to this topic
  • Frostbite

Posted February 05, 2005 - 05:32 PM

#1

NCMountainman had a few heat related questions about wrapping the header pipe and possible side effects on the engine. I did a bit of infrared scanning of my bike last year and found the cause of a very fast boil over problem at idle (they all boil over after a few minutes sitting still. My cause was the right side rad bent a bit closer to the header pipe from a crash. There's only about 1/2 inch clearance on a good day and mine was down to 1/4 which I didn't think much of, but it made a huge difference.
I set the bike on a stand and let it idle and started scanning figuring I'd find a blocked rad or no flow through a hose, something drastic like that since it would boil over at -30 sitting still for less than a minute, which it didn't do before. What I saw was the bottom corner of the rad smokin' hot, heated by the pipe and boiling the coolant. I rebent the rad and cured the problem.
I told NCM that I'd d do abit more scanning this weekend to see what gets hot and where the heat goes.
My camera is calibrated for building inspections and the max temp is 660F and min is 32F. The headpipe of the WR is so thin that it went over that in the 1st 10 seconds.
Here are a few pics from last night and a little Infrared 101 to help you understand what you see.
The camera has different color palattes that it displays images in. I'll leave these pics in the red/blue to make things a bit simpler. In the red/blue palatte, the hottest part of the picture in the range of the camera is dark red, the coldest is dark blue. Everything hotter than the range is white and everything colder than the range is black. OK, here's the important part to remember - the camera automatically sets the ends of the scale for the image(as long as it's within the 32-660) to the hottest and coldest point of the image, so blue is the coldest part of the image and red is the hottest part of the image. That means that red is not always going to be the same temperature, just the hottest part of the picture. If there's an ice cube sitting beside a hotcup of coffee, the ice would be blue, and the coffee would be red. If I turned on a stove burner beside the coffee cup, now the ice would be blue, the burner would be red and the coffee would be somewhere in the middle, yellowish. It's still the same temp but the scale has changed. The scale of each pic is on the side so you know what range you're dealing with.
Also I can adjust the temperature range of the image I'm looking at for higher detail at a certain temperature. I can manually dial my camera in so that the difference between red and blue is only 10 degrees, and I can decide if that 10 degrees is 32 - 42 or 600 - 610. That lets me find what I'm looking for.
Let's say I was looking for a slightly overheating wire in a wall that was only a few degrees hotter than the wall, but there were steam lines near that were in the picture. The hot steam lines would max out my range so I'd never pick up a few degree temp difference. What I do is set my scale to the average temp of the wall, so everything hotter and colder is blacked or whited out and now the wall would be "cool" blue, even though it's room tempand the wire would be "red hot" even though it's only a few degrees above room temp. In these pics I zoned in on certain things for better definition, (like looking for gas in my 4 gallon tank heating up) so in one pic a rad looks smokin hot red and in another pic it may look cool. The rad is the same temp, just the scale has changed. Clear as mud, good!
The camera has it's own image software and it's tricky to keep good quality when transferring images,and I'm on my way out to a party, so I just took pictures of the IR camera LCD screen with my dig cam to speed things up and they turned out pretty well.


Here's the camera.

Here's the screen I took pics of.

This shows how sensitive the IR camera is with the range dialed in. I put my hand on the tire for 2 seconds and then walked back to the cam and took this pic.

Right hand rad, slightly heated by the head pipe but nothing like before when it was bent.

Both rads (with forks and frame blocking some). The left rad looks hotter than the right because the right is a new used aluminum and the left is the original black. They are actually the same temp but the black one gives off heat better than the aluminum one. I can adjust the camera to read the actual temps of various materials due to their "emissivity" but can only set it for the entire image. I can set it for accurate temp of the left or right rad, but not both at the same time. It's set here to read the black rad.

Another example is the aluminum E2 can. It looks fairly cool while the satkable plates, rivets and emblem look hot. Everything is the same temperature but different materials. the aluminum can is thermally reflective and tends to reflect the room temperature back at the camera. A simple way to find the actual temperature of several different materials in one pic is to stick black electrical tape to them. The tape shows the true temp.

Left rad doing it's job keeping the head cool.

In this shot the cold bike is blacked out, the hot engine and pipe is whited out, and I focused on the rad.

The head pipe heats up and cools down very fast. Here is just after shutdown, the pipe cools in seconds, the rad stays hot.

Does the pipe heat the shock reservoir, not much.

I've heard TT'ers asking about problems of fuel heating up in large capacity tanks with the big saddlebags hanging down beside the engine. In this pic you can clearly see the fuel level (orange), about 3/4 tank and is a fairly uniform temperature.

This pic is not what I thought I'd see. The lower part of the tank hanging down beside the engine is cool and the upper part near the seat is hotter. I guess the saddlebag traps the heat and funnels it to the upper part of the tank. So yes, the fuel does get heated, but it's not actually the fuel in the saddlebag that gets hot, but the saddle bag is what causes the fuel to geat hot.

The exhaust stays fairly consistant except for the header curve which is smokin. This picture was taken a few seconds after shutdown. running, the head pipe is out of my 660 range.

And finally my custom heat shield, and it works. It was 350 degrees cooler than the pipe below. (The first pic was taken after shut down simply because I wanted the pipe to be in range for a better shot of the shield.

I hope this wasn't too boring, I normally do walls and ceilings so I find the bike very interesting. If anybody wants to know something specific (within reason) I'd be happy to set up another IR bike session.

After all this, I still don't know if NCM should wrap his pipe or not, maybe at the shock reservoir to keep it cool. If you have a black rad it helps to put a bit of shiny muffler tape on the lower tank above the head pipe to reflect some heat away.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • ncmountainman

Posted February 05, 2005 - 05:52 PM

#2

great job there frostbite, i 've given up on the idea of wrapping the header pipe, too many horror stories came up when i did some research(basically premature pipe failure) i did wrap the bottom radiator core with glass cloth and tin tape so that should help a little. i was also considering taping the underside of the gas tank, now that i see it does heat the gas, it couldn't hurt anything to tape it anyhow. what of painting the rads black? better heat dispersion? special paint or just flat black high temp? about the shock res, i've seen a protective shield made from carbon fibre. it doesn't seem to be affected much though. i think mine just gets hot from the hammerin' my 280 lb a$$ puts on it :cry:

  • Frostbite

Posted February 06, 2005 - 08:42 PM

#3

i think mine just gets hot from the hammerin' my 280 lb a$$ puts on it :cry:


Haha, you may not be far off there. My reservoir barely warmed up sitting still for 4 minutes so I don't think it would get much hotter than that with the air cooling things as you ride. It probably heats up more fromthe shock itself.

Good idea taping the bottom of the gas tank. One thing to remember, as the tape gets dull and dirty it loses it's ability to reflect heat so you may have to change it once in a while, the shinier the better. I think I was putting a new piece on my rad every month or so. I bought a roll of shiny aluminum duct tape and still have most of it left.

If your rads are aluminum then painting them will help, high temp so it'll stay put, any color will do but flat black would give you an extra enth of a degree of cooling. Just a light coat and make sure to get inside the cooling fins since that's where the heat transfer takes place.

Did you try the frying pan trick yet? When you feel how much heat radiates from a colored surface compared to a shiny surface you'll realize that a painted rad will get rid of it's heat faster.




 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.