A cheap way to measure your jugs' temperatures?

I figure with this title, I will catch Mr Riepe's attention. : )

But seriously, I was cruising the online forums today seeing how folks measure the heat put out by their boxer engine cylinder heads while the engine is running.

The usual solutions were trotted out:

• Thermocouple attachments under the spark plugs with wires leading to a meter.
• Touchless Infrared Thermometers one points at each jug for a realtime measurement.
• A dipstick with a thermometer at the top.

Prices ranged from not too bad ($40-100) to high (>$200). Those who read this blog, know my tendency to go cheap (usually to my regret later). So of course, I kept looking.

Then, on the sovietsteeds.com site, this guy posted a picture of how he'd just used a plain old meat thermometer and rigged it onto his engine's jug. Simplicity itself!

I rode to the local grocery store, picked up two for $5.00 each. (If I'd paid attention, I could have bought three for the price of two). They come apart easily enough, I discard the aluminum/tin frame that came with them and carefully pried the cover off:

A couple of small holes to match the holes in the metal strap and the leftover screw size

I used lock washers to hopefully keep the screws in place in spite of engine vibration

In case you've ever wondered what causes the needle to move with temperature changes

Mounted, looks good there to me, the metal strap I just bent and curved around the tappet cylinders

So there you have it, a bit of metal strapping, some leftover screws/nuts and it even looks like it belongs there on the jugs! We'll see how long they last with the engine vibrations and such but for now.....

If they work out, I might do the same for my R80 Beemer's jugs.

Update: 26OCT09: The thermometers were apparently poorly placed to register heat from the jugs, their needles did not move the entire commute home tonight. Back to the drawing board.

Update: 16NOV09: This concept is still a bust.