Lean is less dangerous than rich?

[raz]

For what it's worth, the 1/8 NPT tapered thread is 27 to the inch, not too far from 1 mm pitch, and it's maximum diameter is about 0.400", so its tapered leading end might fit into the 10 mm bung. A brass compression fitting would probably make a tight enough seal for temporary use. Just don't get carried away and jam it in too far.

That makes sense... it should be 10.287 mm with a 1.06 mm pitch. Interesting!

 

Adapters for M10x1 to 1/8" NPT seem pretty common. Like here. Not that I understand how they would look considering the above!?

 

If you go to the Nanmac website, they offer a thermocouple designed for gas temperature measurement with microsecond response time including 1/8 NPT fitting and electrical connector. Look up:

 

PENCIL PROBE "ERODING" THERMOCOUPLE - E12 Series

They seem really good but a little pricey... $245 or even $285 for having it thermally ungrounded I guess?

 

Maybe I could use something like this for $58. Specs 2200°F (1200°C), 500ms response time. This variant of it could be installed near the exhaust without a bung (you just drill a 3/16" hole).

[luhbo]

In order to give you a shift from the now must be tired right hand to the still fresh left one - have you ever thought of using and monitoring a pressure sensor in your engines? I think they exist in spark plug form, just don't know how to get one of them.

 

They could be all what we need. Of course all pondering about thread widths, thread directions, best locations and so on would become useless, alas, but as the days already start to become noticeable longer, that would not necessarily mean a disadvantage, would it?

 

Hubert

[raz]

In order to give you a shift from the now must be tired right hand to the still fresh left one - have you ever thought of using and monitoring a pressure sensor in your engines? I think they exist in spark plug form, just don't know how to get one of them.

 

They could be all what we need. Of course all pondering about thread widths, thread directions, best locations and so on would become useless, alas, but as the days already start to become noticeable longer, that would not necessarily mean a disadvantage, would it?

 

Hubert

Or even better, infer pressure from ionization current. If we can talk Cliff into stuffing that in MyECU, he'd kill all competition

 

This is really interesting reading: http://www.vehicular.isy.liu.se/Publicatio..._PhD_580_LE.pdf Maybe I got it from this forum and we're looping now. Anyway he used such pressure sensor to verify his work. Cool stuff.

[luhbo]

....Cool stuff.

 

Indeed. Thank you. Quite interesting in my eyes is this graph:

 

 

showing that there is quite a broad window for the optimal spark advance value - thus puting into question the advantage of an ion sensing system, compared to the work an implementation would mean.

 

Hubert

[Ryland3210]

That makes sense... it should be 10.287 mm with a 1.06 mm pitch. Interesting!

 

Adapters for M10x1 to 1/8" NPT seem pretty common. Like here. Not that I understand how they would look considering the above!?

 

 

They seem really good but a little pricey... $245 or even $285 for having it thermally ungrounded I guess?

 

Maybe I could use something like this for $58. Specs 2200°F (1200°C), 500ms response time. This variant of it could be installed near the exhaust without a bung (you just drill a 3/16" hole).

 

The $58 probe looks like a bargain, and ought to bolt on. The compression fittings normally are supplied loose, so they can be tightened at the desired penetration.

 

Although the "fast response" is not spec'd, since it uses an open junction thermocouple, it should be suitable.

 

The pitch of 27 tpi works out to a pitch of 0.94mm, close enough for this purpose. A dab of never sieze would be a good idea to get it back out. I hope you do it!

[Cliff]

Ok you have a probe to measure the temperature but how are you going to use this probe in practise ? On the road the power output is always changing and hence the temperature. On the dyno you may as well just use torque/power measurement from the dyno.

You couldn't use it as an ECU feedback.

 

That graph for spark advance is interesting and explains why I was unable to detect much change with spark advance when I last tried to optimise it. Perhaps the main thing is just to avoid detonation.

[raz]

Ok you have a probe to measure the temperature but how are you going to use this probe in practise ? On the road the power output is always changing and hence the temperature. On the dyno you may as well just use torque/power measurement from the dyno.

You couldn't use it as an ECU feedback.

 

That graph for spark advance is interesting and explains why I was unable to detect much change with spark advance when I last tried to optimise it. Perhaps the main thing is just to avoid detonation.

The initial thought was to make a CHT/EGT vs power and mixture graph specifically for Guzzi V11. Not a permanent mount. I'm not sure it will be usable at all and if it wasn't for the snow outside I'd be riding instead of having this discussion

 

Like with CHT/EGT it would be nice to see that spark advance graph specifically from a Guzzi V11. If it's that flat, our current map should really be good enough. Some of you may now say "I told you so"

 

Maybe all this will eventually boil down to me just targetting lambda 0.95 and forget about further tweaking.

[luhbo]

....

Like with CHT/EGT it would be nice to see that spark advance graph specifically from a Guzzi V11. If it's that flat, our current map should really be good enough. Some of you may now say "I told you so"

....

 

Although this curve is quite flat in the interesting area and although this guy seems to say that such a curve would be typical for all engines, well, nevertheless I've seen a lot of very sophisticated looking 3D spark maps with a lot of peaks and a lot of strange looking ditches.

 

The main thing in this document is that the spark advance should be choosen to achieve the max. pressure at around 15° after TDC and that such a ion sensing device is capable to make sure this is the case, regardless whether the engine runs lean or rich or even gets fed with water.

 

The benefits of such a system should be beyond any discussion, I think.

 

Hubert

[dlaing]

Ok you have a probe to measure the temperature but how are you going to use this probe in practise ? On the road the power output is always changing and hence the temperature. On the dyno you may as well just use torque/power measurement from the dyno.

You couldn't use it as an ECU feedback.

 

That graph for spark advance is interesting and explains why I was unable to detect much change with spark advance when I last tried to optimise it. Perhaps the main thing is just to avoid detonation.

Excellent question!

For closeloop an EGT sensor would probably be useless.

Even for the more obvious solution of limiting temperature, it could do the opposite of what you intend.

For example you could set it to back off timing or enrichen to keep it cool, but the reason it is hot may not be too hot of combustion, but rather fuel getting burnt in the exhaust pipe raising the exhaust temperature.

A much better purpose would be to use it for data logging on the road. It should be combined with data from WBO2 and CHT sensors.

With a combination of AFR and the two temperature datas one can have a better idea where to go with fueling and timing. More so than AFR it is heat that makes power, and heat that burns valves.

You can control the heat with timing and fuel. Maintaining consistent heat at the Cylinder head and at the exhaust combined with good AFR numbers will result in an engine that makes good power.

Sure you would be better off if you have a multi-gas analyzer and hours of dyno time to maximize power at every spot on the map, but logging heat and AFR can get you headed in the right direction.

Logging up hill runs is especially useful as map positions can be maintained long enough to get a better idea of what is happening with temperature. On the road it may be impossible to replicate what you can do on a dyno, but it is also impossible to replicate on the dyno, all that you can do on the road.

Using the seat of your pants to measure power, your hands to measure vibration, and your ears to measure knock can also be helpful, but only in a very limited way.

[motoguzznix]

Measuring EGT may be interesting, but one have to be careful with the data:

Coolant or cylinder head temp p.ex. are easy to measure as they do not change in a fast rate. If You take a measurement every 10 s you are exact enough.

 

EGT is a different thing: this temperature can change within a fraction of a second. 10 Hz may be not enough to make the changes visible. So you should measure with 100 Hz at least to get things into perspective. To take into account is also the delay of the EGT measurement compared to the engines actual rpm. This must be measured at the same time. Lambda too to get a useful correlation between these figures. Lambda may have an other delay than EGT, so this must be taken into account too. And without comparing all this data with the relevant power graphs the effort is only worth 50 %.

 

Measuring all of this data needs a professional measurement equipment to handle the data in a correct way. I'm not sure if that makes sense without getting things in the right perspective.