oh BOY do I feel like an idiot today

[J.Jensen]

Ever messed up between metric and imperial units?

After a great day on the mountain, which almost had me CARRYING my sled home, I've realized that my EGT gauges probably show FAHRENHEIT not CELSIUS.

1300 degrees might not be a nuclear meltdown below the head afterall...

The Digatron manual at least says nothing about swithcing between metric/imperial, so I'm guessing it CAN'T.

Besides, 1300 *C probably would have sent my pistons out the can in liquid form...

OH BOY do I feel like an idiot today...

 

[guidoxpress]

lol...

no worries man...your on the path to learning is all

 

[94fordguy]

haha, 1300*C would be 2372*F... at that point, you would not only have melted your pistons, but the whole motor would be a glowing puddle of aluminum at that temp, lol...

no worries

 

[94fordguy]

Actually, come to think of it... 1300*F still sounds pretty dang hot... doesn't Aluminum melt at 1220?

 

[go high fast]

no worries........i misread the torque specs once in the service manual and, as a result, dialed in some major torque to the torque wrench and snapped the bolt off for the primary clutch cover.

I wish I could have seen the expression on my face when the bolt broke and again when I re-read the torque specs.

You should have seen the expression on the guys face at the Polaris Service Dept. when I asked him if he could fix it.

 

[Idcatman3]

Actually, come to think of it... 1300*F still sounds pretty dang hot... doesn't Aluminum melt at 1220?

Yes, aluminum does melt at 1220°F. However, the pistons/motor aren't at 1300° when the EGT is. That has to do with the heat transfer from the gas to the metal. As long as your cooling system is adequate, it sheds the heat fast enough that the gas is at 1300°, but the pistons/cylinders are much cooler. That's why your water temp gauge would only read 120-180°F.

Although 1300° is still pretty warm for an EGT.

 

[J.Jensen]

Actually, come to think of it... 1300*F still sounds pretty dang hot... doesn't Aluminum melt at 1220?

1300F = 700C

I remember from tuning cars we had 850 C as max.

Yes, raw aluminium melts at 1220.6.
Its only a reference as alloys have higher and lower depending on the blend.. Is pure aluminium used for anything except electrical wiring?

The tech guy at Digatron I spoke with today said 1300 is safe, 1400 is trouble. I'll still try adding a click or two with fuel at that spot to get it down a tad...

BUT THE SLED ROCKS

 

[94fordguy]

Yes, aluminum does melt at 1220°F. However, the pistons/motor aren't at 1300° when the EGT is. That has to do with the heat transfer from the gas to the metal. As long as your cooling system is adequate, it sheds the heat fast enough that the gas is at 1300°, but the pistons/cylinders are much cooler. That's why your water temp gauge would only read 120-180°F.

Although 1300° is still pretty warm for an EGT.

True... I was just thinking that even thought the water is cooler, the surface of the piston is going to be substantially hotter. But you are correct, the gas will always be hotter than the combustion chamber materials themselves....

I was always under the impression that the EGTs should be more in the neighborhood of 950* at max?

I don't have EGTs and don't know much about them, so I find this very interesting all around

 

[94fordguy]

1300F = 700C

I remember from tuning cars we had 850 C as max.

Yes, raw aluminium melts at 1220.6.
Its only a reference as alloys have higher and lower depending on the blend.. Is pure aluminium used for anything except electrical wiring?

The tech guy at Digatron I spoke with today said 1300 is safe, 1400 is trouble. I'll still try adding a click or two with fuel at that spot to get it down a tad...

BUT THE SLED ROCKS

Also true... for some reason I remember hearing that most pistons will melt at 1425*F... I was just noting pure aluminum as a reference... either way, 1300 sounds HOT

 

[J.Jensen]

True... I was just thinking that even thought the water is cooler, the surface of the piston is going to be substantially hotter. But you are correct, the gas will always be hotter than the combustion chamber materials themselves....

I was always under the impression that the EGTs should be more in the neighborhood of 950* at max?

I don't have EGTs and don't know much about them, so I find this very interesting all around

I'd really like to know more too! Any learning is good learning. It would be great if some of the guys that build engines and make maps from scratch etc had some knowledge to hand out

I think the digatron manual stated operating range could be as much as 1100-1300F.
Thats the part that got me thinking about Norway = Metric versus the digatron being Made in USA = Imperial...

 

[speedemon]

Josh(jskattum606) has his turbo 900, and when your on it, it runs around 1250-1300 last time i checked... I think these 2 strokes are designed to run that hot!

 

[jskattum606]

Ive never seen 1300 on mine. At WOT im at 1150 and crusing the trail im at 1000 about. I have seen 1200 fairly often while tunning but i add a little fuel then.
This is just with my set up. I had an A/F guage and it would run at about 12.6 at these temps. 1200 WOT was at 13 A/F ratio

 

[diamonddave]

LOL...you guys should be trying to find 1,150 degress Fahrenheit with maybe an occasional 1,175-1,200 F. Yes, 1,300 Fahrenheit is too hot.

 

[speedemon]

My bad, I stand corrected lol I swear it being hotter but guess not!

 

[J.Jensen]

Ive never seen 1300 on mine. At WOT im at 1150 and crusing the trail im at 1000 about. I have seen 1200 fairly often while tunning but i add a little fuel then.
This is just with my set up. I had an A/F guage and it would run at about 12.6 at these temps. 1200 WOT was at 13 A/F ratio

I'll double check my WOT temp and add a click on cruise rpm.

Will any wideband lambda sensor up the can outled be good for tuning or should it be drilled into the pipe or Y pipe for most accurate reading?

 

[jskattum606]

I'll double check my WOT temp and add a click on cruise rpm.

Will any wideband lambda sensor up the can outled be good for tuning or should it be drilled into the pipe or Y pipe for most accurate reading?

You will want the EGT probe in the Y pipe. I think its like 4.5 inches from the piston skirt. Check with whoever you bought the prbe from as it can vary. The wide band O2 sensor i have seen different ways. I have it after the turbo which would be comparable to the can. Ive seen them in the middle of the pipe also.