Infra-what?

“Thermography is the use of an infrared imaging and measurement camera to “see” and “measure” thermal energy emitted from an object. Thermal, or infrared energy, is light that is not visible because its wavelength is too long to be detected by the human eye; it’s the part of the electromagnetic spectrum that we perceive as heat. Unlike visible light, in the infrared world, everything with a temperature above absolute zero emits heat. Even very cold objects, like ice cubes, emit infrared. The higher the object’s temperature, the greater the IR radiation emitted. Infrared allows us to see what our eyes cannot. Infrared thermography cameras produce images of invisible infrared or “heat” radiation and provide precise non-contact temperature measurement capabilities.” Source: Flir.

Surely you’ve seen Predator, right? Infrared thermography is what the Predator used sometimes to detect Schwarzenegger and his gang in the dense jungle.

Basically it’s temperature-vision, and avoidable or excessive heat robs power.

Great, but the cameras are extremely expensive!

Yes, we know. Cool technology is often completely out of reach to purchase unless you have a hefty budget. This is one of those times where rental is going to have to be good enough and luckily there are plenty of inspection companies (among others) with IR cameras. If you perform a search for “property inspection thermal” along with your city and state you’re likely to get many results.

We hired a local property inspector who agreed to take pictures for $100. Ouch. Do you people see what we go through to make these articles even when we’re far from making our first cent of profit yet? Fine, enough of the sob story. By the way, if you just want to rent a camera and figure out how to use it on your own, you can.

Also, a quick note about the cameras: They’re typically far lower resolution than even your typical consumer digital camera. I think the cameras have just started hitting the 2 megapixel range, which is equivalent to digital cameras from about 1997. The pictures taken by our hired help are only 240×240 in original format (and his camera cost $8000!). They have been resized to 480×480 below.

What’s to gain?

With careful examination of your images you should be able to determine problematic areas and develop a plan toward improving them. Perhaps you’ll find that your intake manifold is absorbing too much heat from your cylinder heads. Maybe you’ll find that something is generating far more heat than you imagined possible. Most batteries are known to work poorly in extreme heat. Is your battery absorbing excessive heat due to its position in the engine bay? Are your brake lines properly shielded from the extreme temperatures generated under hard braking? Is your turbocharger completely roasting things nearby? There are hundreds of reasons for this sort of heat analysis.

Images

First we have a head-on shot of the engine bay. The nasty hot spot in the upper left of the image (pinkish white) is a coolant reservoir. Just above and to the right of that you should be able to make out a fairly large pipe with a curve to it. The top of the pipe shows as light blue, the middle portion shows as dark blue, and the bottom appears to be much hotter. How is it possible that a pipe is only hot on the bottom when we all know heat propagates through materials? It turns out that reflective materials and IR thermography don’t play well together. The bogus hot spot you are seeing is actually the portion of the pipe that happens to be reflecting directly back into the camera. More proof and commenting on this with later images. For reference, the single dark blue dot in the middle bottom of the image is where a radiator hose connects to the aluminum radiator (you can see the roughly 170F orange-colored hose if you look closely). The radiator runs left to right and is green, yellow, and blue - colors which do not accurately represent the true temperature.

Below, another view similar to the one above. Take note that the color to temperature mapping legend at the bottom has changed. This is true for each individual image based on the range of temperatures in the entire image. The dark red area just to the left of the camera’s black targeting crosshair (in the center) is the alternator.

The following 302F hot spot is the SwainTech “White Lightning” coated up-pipe to the turbocharger’s exhaust housing. It is actually quite a bit deeper into the engine than the image represents.

Although the car had been sitting for 15 minutes when the following picture was taken, it’s a pretty neat shot showing the actual cooling process, right to left, of the front mount intercooler.

This shot of the front wheel is curious because it shows the disc of the 2-piece rotor itself quite cool (around 100F, blue), the “hat” of the 2-piece rotor at around 126F (almost white), and the spokes of the rim (red) have absorbed quite a bit of the heat that was transferred from the “hat”. The yellowish green slots in the rotor also indicate that they cool more slowly than the exterior surfaces of the rotor (blue).

Once again, proof that reflective surfaces are troublesome to image properly with IR. This side image shows the top of the aluminum radiator (dark blue and to the left of the crosshair) as a cozy 85F. I don’t recommend putting your hand on it to test the accuracy of the IR camera. It’s actually about 220F in this image.

While these specific images may not mean a lot without having the physical engine bay in front of you like we have, hopefully you can gather the importance of this sort of study. If you have any questions or comments, please feel free to speak your mind below. Happy heat hunting. ∞

For the newbie DIYer who needs a little confidence boost to crack open that cylinder head, we’ve made the following video showing a tear-down of a 2002 WRX cylinder head.

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