Thursday, October 15, 2015

Measuring the temperature on Scarlett's heads.

Scarlett, my 2014 URAL Patrol Sidecar, has what is commonly referred to as a Boxer engine.  The formal description is "Horizontally Opposed Pistons Engine" I believe.

These pistons, function inside what is known as the cylinder heads, or "heads" for short.

During the last long set of riding days down in southwest Colorado for the Fall Colors, there had been a time or two where I'd smelled the distinctive smell of burnt engine oil.  Usually that's either a sign of leaking oil falling on some hot surface or an engine that's running hot.

I recalled seeing a set of engine heat sensor gauges on a fellow Uralista's rig during the last group ride.  Tim L. had installed digital sensors from TTO which used as a sensing device a brass ring which is mounted under the spark plug used in each engine cylinder head.

The price was right, less than $40 each and I got two of them yesterday from Amazon.  Installation was easy and the only real complaint so far is the length of the wiring is a bit short, forcing one to use the leg shields as a mounting point, and not the handlebar.

 Left cylinder's sensor, mounted near top edge of leg guard
LINK to product on Amazon

 My view of the sensors while riding.

 views of the sensor cable at each spark plug

As I had already suspected from comparison to other thermometer readings I'd seen while riding, the aquarium thermometer I use to measure ambient temperature on my handlebar reads two degrees warmer than actual air temperature:

Tim L. reports his cylinder heads run in the 300s Farenheit when riding, I'll be tracking my own to see how hot the heads on an EFI rig run.

Once I have a baseline, I'll be in a better position to judge whether the engine might be overheating on the hotter days of riding.

First ride with sensors: Ambient temp 54F, heads ran in the 330s Farenheit.  High was 369F on left head and 368F on right head.


BMW HACKER said...

Pretty cool gadgets. I wouldn't mind having a pair on my rig....but it would probably scare

RichardM said...

Nice, clean install. Do these use standard thermocouples or a solid state sensor?

redlegsrides said...

Richard, here's the link to the info page.


RichardM said...

Their description doesn't say anything. The reason I mention it is that if it is a thermocouple, the voltage being measured is in the millivolts and may be affected by the high voltage in the spark plug wire. It may shorten the life of the gauge. This is only an issue if they are run in parallel not simply crossing.

redlegsrides said...

Thanks RichardM, sent them an email asking....will let you know as well once I find out.

Coop a.k.a. Coopdway said...

Richard's question was definitely more technical (and more on the mark) but I was curious as well about "shared" readings from the plug leads.

redlegsrides said...

Coop and RichardM:

Heard back from friend who's had the same gauges on his rig last couple of years, he ran his wires parallel to the spark plug wires, no issues. Awaiting word from manufacturer.

redlegsrides said...

BMWHacker...not sure overheating is as much a possibility on Airheads as they are on URALs. :)