Riding engine temperature

BigJimmyW13

BigJimmyW13

XS650 Guru
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I'm wondering what is thus safe temperature spectrum of the engine on these things. If anyone can tell me that'd be awesome!

I'm wondering what the top end of the safe surface temp is?

Posted via Mobile
 
Safe? Who knows.

I take readings after every ride with a infrared thermometer, usually on the cylinder head right behind(to the rear of) the spark plugs. I also take readings at the top fin of the jugs, and those readings are usually a few degrees cooler than the plug area. It depends a lot on ambient air temperature. My highest readings on a 100F summer day were 330F, 335F. Carbs setup right, plugs a nice tan color in all throttle ranges.

At 75F air temperature I get more around the 250F range. I like this much better.

Any speed less than 40mph doesn't seem to really cool it much. Not always possible in the city. XSJohn was reporting temps in the 220F range with an oil cooler and wind deflectors and lower compression.

My air-cooled aviation friends assure me that anything less than 375 is fine. The rear cylinder on Harleys run in the 340 range, I'm told. But I've also read that cycling aluminum in the 300s shortens the metal's life, so I try to avoid it.

Would like to hear others opinions on this. I'll definitely be making some changes before next summer.
 
With my oil cooler, the cylinder temps on a 95 day are about 255. Stock engine, good tune on carbs, K&N pods, punched out stock exhaust. 17/30 sprockets. 75 day-230 cylinders.
 
Just move up here to Canada..................you won't have to worry about high engine temps:)

September again................anybody seen my long underwear, gloves and heavy duty riding coat??
 
84F air temp

Measured 259 left and 265 right, just behind the spark plugs, after interstate ride.
 
This is interesting... stumbled on this thread again this evening. Has anyone ever experimented with a cylinder head temperature gauge - perhaps a dual gauge - that uses a thermocouple ring mounted under the spark plugs? I can see some merit in knowing your head temps at any given time.

TC
 
A friend of mine upgraded to a digital on his power paraglider flying machine he gave me his old set up,
Came with small chrome LED volt gauge
2 sensors and a gauge with 2 needles one for each sensor (exhaust Temp Sensors and Gauge)
1 Head temp sensor and gauge it is set up for a spark plug
I plan on putting it on my bike this winter
Should be interesting to see whats going on And may help me get it tuned for good mileage and performance.
 
Hey, blue... I was reading an article on an ultralite installation, similar to what you reference. The pilot described the installation, but it was one gauge that measured the temp on a 2-stroke head. It used a ring-type thermocouple.

Westach has several dual ones, in Celsius and Fahrenheit, that use J-type ring leads. None of this is inexpensive, but I can see the merit in knowing your head temps on an August afternoon in a backup on Rt. 29.

One thing, though, is that our plug ports are pretty deep, so I'm not sure how difficult it would be to accommodate a (14mm? for our plugs, maybe?) ring.

Also, I was researching the differences between CHT and exhaust gas temperature (EGT) gauges. Evidently, the latter are much more sensitive to lead placement, more difficult to install, and really only useful in the tuning phase.

Interesting stuff!

TC
 
Yup, he's on here and makes a nice piece! It's crankcase oil temp, though. I had bought an RR brand one before I knew about his, and I find it really useful. Having head temps at a glance would be useful too, though, I think, on an air cooled motor.

TC
 
I've just been shooting my infrared thermometer down the oil filler hole. Oil temps were around 160F on a 70F day with an oil cooler.
 
pyrocentric said:
I've just been shooting my infrared thermometer down the oil filler hole. Oil temps were around 160F on a 70F day with an oil cooler.
Click to expand...

Now, that actually seems low to me. I think Tony C told me once that the oil has to be about 160F minimum in order to burn off condensate in the crankcase. In this cooler Maryland weather, mine has been running about 212F at op temp. This past summer, I have seen 240-ish, but it will rise and fall with movement, of course. But maybe your cooler makes that much difference, which would be what you set out to do. :)

I'm sorely tempted to experiment with a Westach dual head temp gauge, but those and the feeds (the thermocouples replace the compression washers under the spark plugs) would run around $150.00. I'm wanting a baritone acoustic guitar, though, so the gauge may have to wait.

TC
 
From some of the testing i have done, an oil cooler set up with a cooler the size of the one Mike's sells will drop oil temps from the 200-210 range to the 150-160 range.
It also brings the head and cylinder temps down about the same amout, 50 degrees.
On our bikes during most of the riding season, and the 1000-1500 oil change intervals, condensation won't be much of a problem.
Those who tend to do short rides in cooler weather, then condensation might be a problem.
I think the benefits of the cooler out weigh any condensation problems.
Several companies make inline temp controled valves that work like the thermostat in a car engine. Keep the oil bypssing the cooler until the oil temp reaches 180, then open up and oil circulates through the cooler to keep the temp about 180 to 200.
Jegs sells one for about $50.
The head temp sensors under the plugs would be a nice add on if the prices were better. A $40 infered laser thermometer is cheaper and can be used for many things. I have the item # 93984 from Harbor Frieght that works very well, about the size of a cigarette pack. They sell a smaller one but the max temp is to low on that one.
Easy to use, when stopped in the hi-way traffic jam just pull it out and shoot your engine. It has a neck cord with a quick disconnect.
Leo
 
XSLeo said:
The head temp sensors under the plugs would be a nice add on if the prices were better. A $40 infered laser thermometer is cheaper and can be used for many things. I have the item # 93984 from Harbor Frieght that works very well, about the size of a cigarette pack. They sell a smaller one but the max temp is to low on that one.
Easy to use, when stopped in the hi-way traffic jam just pull it out and shoot your engine. It has a neck cord with a quick disconnect.
Leo
Click to expand...

I think it would be really hard to argue against the merit of an oil cooler of some sort. I have the Heiden one, mainly because I'm just not presently up to doing the sort of plumbing that an in-line cooler would require.

On the matter of head temp gauges, there is definite merit, but I agree that it seems a bit costly initially; I could do a bullet case-mounted setup with a new Westach dual (left and right cylinder in one gauge) instrument and steel braided feeds for a little over &150.00. Thinking about it. I have at least as much in this bike again as I paid for it anyway...

TC
 
I'm with XSLeo on this. Buy the $40 HF sensor, and use it for a couple of months while comparing it to your dipstick-thermometer temperatures. After a while, you should develop a good sense of what is happening in the heads by simply observing the dipstick-thermometer, and it won't require any wiring or plumbing, keeping the bike looking clean, and is an inexpensive solution.
http://www.handspiral.com/ThermoDipStick.htm
 
DogBunny said:
I'm with XSLeo on this. Buy the $40 HF sensor, and use it for a couple of months while comparing it to your dipstick-thermometer temperatures. After a while, you should develop a good sense of what is happening in the heads by simply observing the dipstick-thermometer, and it won't require any wiring or plumbing, keeping the bike looking clean, and is an inexpensive solution.
http://www.handspiral.com/ThermoDipStick.htm
Click to expand...

That's a good idea... I had not thought of doing that, specifically. It makes sense though; I'd imagine there's a direct, predictable, consistent correlation between the crankcase oil temp and the head temps.

TC
 
Perhaps while all is good the oil temp will roughly corollate with cyl temps. but it's when things are turning to shit at a very rapid pace that it will let u down. plug temp gauges sound like the go. awesome for tuning and hard reving! :thumbsup:

Posted via Mobile
 
That's about what I paid for it on sale. I think regular price was $39. The one in the upper right corner is the one that won't read high enough, I got that on first. I think I got it for $9.
When I was doing the oil temp testing a few years back, the headcylinder temps ran about 50 degrees cooler with a good cooler installed. Oil was around 200, dropped to 150 with the cooler. Head temps shot at spark plug was 290, with cooler, 240. I'll try to do better testing next year. Need to build headers that have clearance for modded cover and elbows to hook the cooler in.
Leo
 

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