Thermocouple on tree monkey 661 hp2 & motul 800

[Redbull661]

tinkering with this thermocouple...

 

[Duane(Pa)]

Pretty cool! Where, exactly, is the sensor on the engine?

 

[Glock37]

Wow 1860 exhaust temp we powder muffs and its good too 800 and its not burning off Interesting. No we didnt powder anything on this saw but on mine and others we did i expect similar temps with those saws and mix cant get enough info !


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[Deets066]

Pretty amazing that an aluminum piston holds up to those temps.

Last I knew aluminum melts around 1250 to 1300

 

[bwalker]

Are we assuming the faster a combo comes up to temp the better?

 

[Hinerman]

Pretty amazing that an aluminum piston holds up to those temps.

Last I knew aluminum melts around 1250 to 1300

1220.58° F to be exact. Doesn't make sense. The only thing I can think of is the piston and cylinder are some sort of aluminum alloy with a higher melting point,,,,or not.

 

[Stump Shot]

Tachometer reading at same time would be interesting.

 

[bwalker]

1220.58° F to be exact. Doesn't make sense. The only thing I can think of is the piston and cylinder are some sort of aluminum alloy with a higher melting point,,,,or not.

There is a boundary layer of gas that insulates the pistons crown from the combustion chamber. When detonation occurs this boundary layer is blown off, which is why the piston begins to melt.

 

[Stump Shot]

Pistons transfer heat to cylinder walls, as well as they are cooled by the incoming charge of fuel.

 

[smokey7]

Very interested in this. I always tuned 2strokes when a egt gauge was present around 1300. That's egt but combustion temp that's different than egt is it not. If becurious to see a probe in the flange muffler entrance. Its funny how hp2 took longer to hit peak temp wonder why?

 

[Red97]

Pretty amazing that an aluminum piston holds up to those temps.

Last I knew aluminum melts around 1250 to 1300

1220.58° F to be exact. Doesn't make sense. The only thing I can think of is the piston and cylinder are some sort of aluminum alloy with a higher melting point,,,,or not.

That is the actual gas temps.

The fuel/oil mix creates a "layer" over the piston crown to help prevent that heat soaking.

Along with the squish band effect, majority of the high heat is contained to the chamber.

 

[Keith Gandy]

Im as lost as a goose! What does this mean when 1 oil heats quicker than another? What are we looking for here?

 

[Keith Gandy]

That is the actual gas temps.

The fuel/oil mix creates a "layer" over the piston crown to help prevent that heat soaking.

Along with the squish band effect, majority of the high heat is contained to the chamber.

So the higher temp of the 800t means the mix is containing the heat to the combustion chamber and not heat soaking the piston and cylinder? Is this a plus or a minus? Does the heat need to soak to the piston and cylinder fins to cool or would it be better for it to stay in combustion chamber and pass on out exhaust?

 

[bwalker]

So the higher temp of the 800t means the mix is containing the heat to the combustion chamber and not heat soaking the piston and cylinder? Is this a plus or a minus? Does the heat need to soak to the piston and cylinder fins to cool or would it be better for it to stay in combustion chamber and pass on out exhaust?

To me it means that 800T has a higher BTU content that HP2.

 

[5000+]

Is the saw still mtronic? Changing oils may need a certain amount of run time to relearn. Some contribute to combustion others not so much.

 

[Stump Shot]

Is the saw still mtronic? Changing oils may need a certain amount of run time to relearn. Some contribute to combustion others not so much.

Run time will help with friction differences as well, as it takes a bit for one oil to replace the film the one prior left behind.

 

[Keith Gandy]

To me it means that 800T has a higher BTU content that HP2.

Which means what Ben? More energy in the combustion process?

 

[Redbull661]

Is the saw still mtronic? Changing oils may need a certain amount of run time to relearn. Some contribute to combustion others not so much.

I did 5 cuts in another log after changing.

Im as lost as a goose! What does this mean when 1 oil heats quicker than another? What are we looking for here?

means we need more data! lol more tinkering with different ratios and different oils to figure out what is going on exactly and if this setup is what we want to use in the BIG test.

 

[Red97]

I did 5 cuts in another log after changing.



means we need more data! lol more tinkering with different ratios and different oils to figure out what is going on exactly and if this setup is what we want to use in the BIG test.

Did you get times on those 2 runs?

seems the hotter the temp, the more "energy" is released, now if that translates into more pushing the piston down i don't know.

 

[Stump Shot]

I can see where there could be a lot to this, I do wish you well with your testing. Have one more thought, maybe when you're all done, save the oil samples you have and do a pour test this winter. To me that would be extremely interesting. A lot to this oil business...