IN AN EARLIER POST I WAS TOLD MY EGT SENSOR IS TO CLOSE TO MY CYLINDER. HOW FAR AWAY IS IT SUPPOSED TO BE. I AM PULLING THE EXHAUST OFF THIS WEEKEND AND RELOCATING THE EGT. JUST NEED TO KNOW WHERE IT SHOULD GO

 

I believe they are supposed to be 6-8" from the piston.

 

4 to 6 inches is where most need to be. It needs to be as close to the tip of the exhaust flame as possible, the closer the more accurate.

 

Here's a pretty good article. Probe placement

 

I'd go with what the manufacturer of the probe recommends.

If you were wanting to compare your readings with other DS readings, you'd want to use the same probe location as theirs.

If you're not comparing readings from others, the location isn't that important. The reading is more of a reference point.

Readings are going to be different from one probe/gauge to another and based on location. I've seen 4 stroke readings posted on the web that varied from 1050 to 1650. What you'd want to do is pick a probe location, then on a dyno see what temp makes max power. After that, always make sure the reading is what you got at max power on the dyno.

My probe is way back in the collector. What I've done is use an air/fuel meter and set the jetting where max power occurs, then see what the EGT reads. I keep an eye on the EGT to see if it ever creeps up beyond this. FYI, mine reads 1200 at WOT, but I don't believe it's 100% accurate.

 

Scooby I agree with you for the most part. The only problem is that by the time the heat gets back to the collector the temps can go down sometimes 300 to 400 degrees. The same theory for your quad applies to diesel engines. People that are lazy put their temp probe behind there Turbo at the exhaust inlet, which is not the correct place to put it. By the time the heat gets thru the Turbo and reaches probe it is 300 degrees cooler than the exahust coming out of the collector of the exhaust manifold. Hence the reason to put the probe as close as possible without destroying it. I would say about a good 4 inches from the head would be sufficient on the DS. Just remember your Piston starts to break down at 1300 degrees, it can stand this temperature for about a minute maybe 2, but then say BYE-BYE piston!

 

I agree with Scooby and The punisher.

Just remember that aluminum melts at 1300 degrees. It will take a little wile to get that piston that hot, but, it can get there.

Also, remember that those HOT flames are passing accross the valve guides. If they heat up to much, they will swell and slow down the valve. I and Mr. Horsepower thought about this AFTER I had my exhaust valve touch my piston. I was running the big springs and Ti. retainers, so did not think to much about it until I was brainstorming with him. I had my bike running the best it had (lean) and on the third consecitive trip down the track, they met and had a relation.......Not a good one.

Just some thought on how hot and how hard you want to run your bikes.

I run my trail bike around 1200 deg. with the probe about 4 to 6 inches from the piston

DuneDevil