exhaust temperature readings

[LarryA_Texas]

This may sound over the top but I'm curious if anyone here has measured the temperature of the exhaust pipes at the head? And have you used those readings to tune the carbs?

A little background before you all think I'm nuts: most, if not all, piston airplanes have a mixture control and an exhaust gas temperature gage (EGT) in the cockpit. With that gage you lean it out until the temp peaks (without the gage you just lean it 'till it runs rough) then rich it slightly to bring the engine back to smooth or bring the temp down a little. It's necessary because airplanes operate at different altitudes.

So, why couldn't you do this while tuning your motorcycle? Are there EGT probes for motorcycles? I've never seen one. I have heard of infrared sensors you can buy to check for heat, which would be a reasonable measure of heat inside the pipe.

It just seems like if you knew what the target EGT was you could set your carbs and sync them pretty quickly and accurately. It would take some of the mystery out of what it's doing without reading the plugs.

Just curious if anyone has heard of this, or if it seems possible, practical, or useful.

 

[Guest]

I'm about to do exactly what you're talking about. I've wanted to use an infrared temp gauge in conjunction with a Colortune. I think that one could really dial their carbs in that way. The Colortune would get you close, then fine tune them with the temp gauge, and set all your carbs the same.

With stock pipes being double-walled, it would probably work better with a header.

Here's the gauge I'm going to try:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96451

I'll post back my results.

 

[bonanzadave]

Just curious if anyone has heard of this, or if it seems possible, practical, or useful.

Ive installed dozens of those gauges in Continental 6 cyl engines and I think it would be a great idea on a bike.

The draw back to adapting the aircraft gauge to a bike is the almighty $$$. A digital bar graph gauge is over a grand and each probe is over $100.00. Plus who wants to drill four holes for four EGT probes hoseclamped to their head pipe with wires running up to a gauge.

Funny thing is airplane engine technology is stuck in the 1950s and the engines ran fine back then without a $2000 gauge to tell you the temp of each exhaust flame.

 

[Steve]

I have not measured temps on a bike, but I used to drive a truck that had a pyrometer. Different trucks that I had the chance to drive had the pyros either before or after the turbo, and we were instructed to keep the temps below a certain number while driving.

Later, I installed a turbo on my Toyota Corolla :shock: \\/ and also installed a dash full of gauges, including exhaust temp. I was really surprised to see how much higher the gas exhaust was compared to diesel exhaust. I only had one probe, and it as after the turbo, but I only had one carb, so tuning might have been easy, if I only knew what a good target would have been.

By the way, after years of operating trucks and keeping the temp below 1300 if the probe was ahead of the turbo or 1050 if the probe was after the turbo, it was rather eye-opening to see temps int the car hit 1750 on an extended high-speed run. :shock: (That dang Corvette kept wanting to pass. 8-[ )

Do you have any idea what your target temperature would be?

.

 

[dardoonk]

....I installed a turbo on my Toyota Corolla.. That dang Corvette kept wanting to pass.

LMFAO - would have loved to see it!

 

[bonanzadave]

Here ya go ! Drill 4 holes in your head pipes and then plug em with a ss screw when your done......

JPI SLIMLINE EGT
JPI SlimLine - Exhaust Gas Temperature (EGT) Indicator.



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Our Price $275.00 Quantity:

JP Instruments SL-EGT
Part Number EI0019 Product Details [FONT=Verdana, Arial, Helvetica, sans-serif]SlimLine - Exhaust Gas Temperature (EGT) Indicator - includes sensor[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]These gauges all have a bright red, and easy to read illuminated displays and can be purchased separately, or in clusters, depending on your specific needs. The SlimLine? gauges are really popular with the budget conscious kit-plane pilot who refuses to sacrifice reliability and accuracy, when it comes to engine and flight data.[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]These gauges are designed to save panel space and provide you with the accurate information you need to keep flying safely. [/FONT]

 

[Steve]

LMFAO - would have loved to see it!

That's when I found out that my '74 Corolla (1.6 engine) would do redline in 5th gear. :shock:
Showed about 125 on the speedo, which was remarkably accurate.

.

 

[Guest]

Here ya go ! Drill 4 holes in your head pipes and then plug em with a ss screw when your done......

JPI SLIMLINE EGT
JPI SlimLine - Exhaust Gas Temperature (EGT) Indicator.




(Larger View)

Email this to a friend ​

Our Price $275.00 Quantity:

JP Instruments SL-EGT
Part Number EI0019 Product Details [FONT=Verdana, Arial, Helvetica, sans-serif]SlimLine - Exhaust Gas Temperature (EGT) Indicator - includes sensor[/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]These gauges all have a bright red, and easy to read illuminated displays and can be purchased separately, or in clusters, depending on your specific needs. The SlimLine? gauges are really popular with the budget conscious kit-plane pilot who refuses to sacrifice reliability and accuracy, when it comes to engine and flight data.[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]These gauges are designed to save panel space and provide you with the accurate information you need to keep flying safely. [/FONT]

Do you think the infrared gizmo would work?

 

[dardoonk]

Do you think the infrared gizmo would work?

I am wondering the same thing. I'd think the IR gun would work at idle/ low rpm. Can you get an accurate plug read at 1/3 throttle if the bike is not under load? IE: sitting on the centerstand? If so, maybe it would work then too.

For under $40 bucks, it might be worth looking into.

 

[80GS750]

it only goes up to 968 farenheit.. is that high enough????

 

[flyingace]

I'm sorry - what am I missing? Drill holes in my exhaust pipes and pay thousands of $ to tune my $850 bike? Over the top doesn't begin to describe it...

 

[bonanzadave]

Over the top doesn't begin to describe it...

Exactly ! There are easier proven ways to dial in these old bikes.

The infra red gun wont tell you much and by the time you figure which cyl is running cooler the cyl next to it will be heat soaking it anyway. The only true way to do an EGT monitor is to have a probe IN the flame.

 

[earlfor]

To measure exhaust gas you will need a probe installed in the airstream. Aircraft supply companies sell EGT kits and gauges. They are not cheap.
Exhaust gas temperature is normally between 1200-1400F.

Earl

 

[SteveR]

EGT install

EGT install

Just a quick note... Remember that your exhaust pipe may be a double wall pipe. Keep that in mind when installing the probes.
Also, an aircraft engine with a constant speed prop is operated mostly at fixed power settings. EGT is important at full power settings and for fuel management at cruise power settings.
Our engines are all over the map... all the time.
So, in the end, I decided not to install EGT probes, thinking that I cannot adjust the mixture of each carb while riding. The compromise that a CV carb provides when it is tuned correctly, by "correctly", I mean for the mission intended and the patience required to setup low and high fuel flow and sync at a given altitude, is good enough for me.

 

[Guest]

I've wondered about this as well.We use hand held laser temp guns at work to check bearings etc,and thought about using this to look at exhaust temps.My 'S is running just fine so I wouldn't play with it anyway.I also wondered whether this would be all that accurate anyway because the 2 inside cylinders would probably run hotter than the outer.I wouldn't spend heaps of moola on an aircraft type set up just so I could wave my d#ck around and say " look what I've got ".Cheers,Simon.:?

 

[rusty boltz]

I use the IR thermometers at my shop to check for bad injectors on diesels they also work great for finding dragging brakes, plugged heat exchangers, bad catalytic converters and more. It was worth every penny I paid. However, I can see how tuning your bike with it my be futile for the many reasons in prior posts. At best you might be able to spot a misfiring cylinder. Besides, you'd look funny riding down the road trying to aim the red dot on the pipes. My opinion is they kick ass but I don't know if it would work for tuning accurately.

 

[LarryA_Texas]

conclusion

conclusion

In case anyone reads this far down, here's what I found. The IR heat gun works good for checking if one is not firing. It's worthless for tuning the carbs. The temp ranges from 250 to about 350 on the outside of the pipes...no clue to what the EGT would be inside.

When I first get one up and running it's nice to be able to see if all 4 are running close. It's worth if for that. Before I would just slap the pipe to see if they all burned my hand about the same amount. This is much more accurate and a bit less painful. But for carb adjustment the temps are too erratic. It bounces up or down 20 degrees and other tuning methods work better anyway. A high-dollar EGT gage might work, but it's not worth the money.

In my humble opinion.