Honda Power Unit Hardware & Software

[etusch]

I would think about this like that they are cooling cylinder block and engine head independently. I think lubrication is also in the same way so more reliable connection point for those block and head.

[johnny comelately]

I would think about this like that they are cooling cylinder block and engine head independently. I think lubrication is also in the same way so more reliable connection point for those block and head.

Yes I agree that "They" would have to have different temperatures for the heads and block. One to enable combustion strategy and the other to maintain piston to bore clearance because the head temperature would give far too much piston clearance. Maybe this has been proven elsewhere??

I've moved on from talking about humidity, far too risky

[hardingfv32]

Actually you are concerned about oil viscosity on the cylinder walls, reducing drag. Clearances can be set for what ever temperature you are running at.

Brian

[johnny comelately]

Actually you are concerned about oil viscosity on the cylinder walls, reducing drag. Clearances can be set for what ever temperature you are running at.

Brian

Yes Brian, very much so. It is just easier to manage differing expansion rates at lower temperatures particularly for combustion management and I am guessing for tribological optimising as well. IMO

[BassVirolla]

Yes I agree that "They" would have to have different temperatures for the heads and block. One to enable combustion strategy and the other to maintain piston to bore clearance because the head temperature would give far too much piston clearance. Maybe this has been proven elsewhere??

I've moved on from talking about humidity, far too risky

It's quite old tech, even in mass production engines, but the standard solution is to run one cooling circuit with two separated coolant outlets (one from block; another from head) to the radiator, having a different thermostat each outlet to open and close the coolant passage at different temperatures

[PlatinumZealot]

100% RH is the upper limit for AH (AH = SH = Specific Humidity, usually expressed in (g of water)/(kg of dry air)) If the air contains more water than this, the extra is no longer water vapor but liquid - perhaps in microscopic droplets - a mist.

This liquid water (mist) has very different properties to water vapor. Engines love it because when heated it will absorb a massive amount of energy during vaporisation - reducing the temperature of the working fluid (the charge air or combustion gases).

As I said above, 25g/cu m is not super saturated at 40*C - only about 60% or so RH.

AH can go well above the Rh of 100% = supersaturated.
As I said the 25 grams was arbitrary, if the discussion was centred around superaturated you would lose the hill
The energy involved to break that quantity of H2O molecules would cause inconsistent propagation at those lambdas.
That is why it stopped detonation in the aircraft scenario.
Not getting on the merry go round GG

No. Relative humidity cannot go above 100%.

This is not a liquid solution. At 100% water simply starts precipitating from the air. Which is already happening in the clouds with the rain falling down to the track.

[Watto]

100% RH is the upper limit for AH (AH = SH = Specific Humidity, usually expressed in (g of water)/(kg of dry air)) If the air contains more water than this, the extra is no longer water vapor but liquid - perhaps in microscopic droplets - a mist.

This liquid water (mist) has very different properties to water vapor. Engines love it because when heated it will absorb a massive amount of energy during vaporisation - reducing the temperature of the working fluid (the charge air or combustion gases).

As I said above, 25g/cu m is not super saturated at 40*C - only about 60% or so RH.

AH can go well above the Rh of 100% = supersaturated.
As I said the 25 grams was arbitrary, if the discussion was centred around superaturated you would lose the hill
The energy involved to break that quantity of H2O molecules would cause inconsistent propagation at those lambdas.
That is why it stopped detonation in the aircraft scenario.
Not getting on the merry go round GG

No. Relative humidity cannot go above 100%.

This is not a liquid solution. At 100% water simply starts precipitating from the air. Which is already happening in the clouds with the rain falling down to the track.

the relative humidity can exceed 100%, in which case the air is said to be supersaturated. Introduction of some particles or a surface to a body of air above 100% relative humidity will allow condensation or ice to form on those nuclei, thereby removing some of the vapour and lowering the humidity.

https://en.wikipedia.org/wiki/Humidity

Sees it can in certain conditions and its considered supersaturated

[PlatinumZealot]

the relative humidity can exceed 100%, in which case the air is said to be supersaturated. Introduction of some particles or a surface to a body of air above 100% relative humidity will allow condensation or ice to form on those nuclei, thereby removing some of the vapour and lowering the humidity.

https://en.wikipedia.org/wiki/Humidity

Sees it can in certain conditions and its considered supersaturated

Oh come on. That's a bit artificial isn't it? Floating other particles in the air to hold the water droplets. And it doesn't apply to typical conditions anyway. Special case..

[gruntguru]

Actually supersaturation can only occur in ultra clean air. Any particles in the air act as nucleation sites and water vapor in excess of 100% RH will immediately condense on those particles and reduce the RH back to 100%.

A racetrack is NOT a location where you would ever find ultra clean air. You will never find RH greater than 100% at a racetrack.

[AR3-GP]

Actually supersaturation can only occur in ultra clean air. Any particles in the air act as nucleation sites and water vapor in excess of 100% RH will immediately condense on those particles and reduce the RH back to 100%.

A racetrack is NOT a location where you would ever find ultra clean air. You will never find RH greater than 100% at a racetrack.

I've managed to superheat water in a brand-new stainless cooking pot with bang average tap water. Never discount the possibility.

[johnny comelately]

OK, enough of the humidity digression.
The original hypothesis was from the Honda engine problems:
1. Honda had a problem in Singapore
2. Horner talked about unusual circumstances and humidity
3. I put forward that maybe the mapping did not cater for the very high humidity
4. Gruntguru says that they would have covered that in their mapping.
5. Understand the difference between relative, absolute or specific humidity.

If you have spent time in those climes and coming from lower humidity places, you know it can be hard to breathe particularly if you are doing some work.

Normally in higher humidity you lean off and sometimes change the timing, but of course modern mapping takes care of that as some MAF sensors have humidity measurement.

Manufacturers that sell vehicles in those climes would make sure they function properly, I know thay spend a lot of time ensuring vehicles perform in all circumstances, so maybe just maybe Gruntguru is correct.

So all this talk about the upper end of humidity is almost a moot point. High is high.

Moving on, then what was the cause of Honda's problem?

As mentioned elsewhere Otmar spoke about Renault engine problems too where they sent the engine back to Very to analyse. He cited the circumstances included from 2nd gear starting ...

[AR3-GP]

OK, enough of the humidity digression.
The original hypothesis was from the Honda engine problems:
1. Honda had a problem in Singapore
2. Horner talked about unusual circumstances and humidity
3. I put forward that maybe the mapping did not cater for the very high humidity
4. Gruntguru says that they would have covered that in their mapping.
5. Understand the difference between relative, absolute or specific humidity.

If you have spent time in those climes and coming from lower humidity places, you know it can be hard to breathe particularly if you are doing some work.

Normally in higher humidity you lean off and sometimes change the timing, but of course modern mapping takes care of that as some MAF sensors have humidity measurement.

Manufacturers that sell vehicles in those climes would make sure they function properly, I know thay spend a lot of time ensuring vehicles perform in all circumstances, so maybe just maybe Gruntguru is correct.

So all this talk about the upper end of humidity is almost a moot point. High is high.

Moving on, then what was the cause of Honda's problem?

As mentioned elsewhere Otmar spoke about Renault engine problems too where they sent the engine back to Very to analyse. He cited the circumstances included from 2nd gear starting ...

Renault's issue was the power train exploding. It's likely related to "lugging" from the 2nd gear start. Too much pressure inside the combustion chamber and not enough relief (piston velocity) can damage the engine and lead to failure like we saw.

This has nothing to do with Honda's issue which was driveability. Why does an engine which in most conditions has no issues and for which it's entire operation sequence pre-programmed and repeatable, suddenly have drivability? This happened to both Max and Checo in the race.

It could be contamination in the fuel (doubtful). I like the humidity theory.

[PlatinumZealot]

Actually supersaturation can only occur in ultra clean air. Any particles in the air act as nucleation sites and water vapor in excess of 100% RH will immediately condense on those particles and reduce the RH back to 100%.

A racetrack is NOT a location where you would ever find ultra clean air. You will never find RH greater than 100% at a racetrack.

I've managed to superheat water in a brand-new stainless cooking pot with bang average tap water. Never discount the possibility.

Wait a second. You say you superheat water.... That is directly above and intermingling with another body of water below it...

Erm.. Not possible.

You can only superheat dry steam. You won't find dry steam directly above a body of water.

Let's say you use vacuum to lower the vapour pressure above the body of water, you still have to transport the steam to where it can get heated dry, before it is superheated.

[AR3-GP]

Actually supersaturation can only occur in ultra clean air. Any particles in the air act as nucleation sites and water vapor in excess of 100% RH will immediately condense on those particles and reduce the RH back to 100%.

A racetrack is NOT a location where you would ever find ultra clean air. You will never find RH greater than 100% at a racetrack.

I've managed to superheat water in a brand-new stainless cooking pot with bang average tap water. Never discount the possibility.

Wait a second. You say you superheat water.... That is directly above and intermingling with another body of water below it...

Erm.. Not possible.

You can only superheat dry steam. You won't find dry steam directly above a body of water.

Let's say you use vacuum to lower the vapour pressure above the body of water, you still have to transport the steam to where it can get heated dry, before it is superheated.

I have no idea what you are on about but what I've explained and personally attest to experiencing is demonstrated in this video:

[PlatinumZealot]

I have no idea what you are on about but what I've explained and personally attest to experiencing is demonstrated in this video:

Huh lol wut?