Honda Power Unit Hardware & Software

[63l8qrrfy6]

Viscosity is measured at -40c I think the viscosity of water is a little higher than the Evan's coolant at -40c.

Waterless coolants are generally ethylene glycol based and as such have a higher viscosity compared to water.
Sure, at -40 c the water is solid but luckily race engines do no sit outside in the winter.

[Marti_EF3]

So, you mean that a water based coolant is better than a waterless on hot conditions??

[godlameroso]

So, you mean that a water based coolant is better than a waterless on hot conditions??

Water has higher specific heat and probably works better for cooling, the waterless coolant is probably good enough.

[63l8qrrfy6]

So, you mean that a water based coolant is better than a waterless on hot conditions??

A very high water content (>90%) coolant, yes.
If you compare waterless coolants to a standard 50% water coolant then yes, the waterless coolant is probably better.

However in high performance engines there is no need for anti freeze additives and only a very little amount of corrosion inhibitors are required - as such it is not uncommon to have 95% water which is most definitely better than any waterless coolant I know of.

[Marti_EF3]

So, you mean that a water based coolant is better than a waterless on hot conditions??

A very high water content (>90%) coolant, yes.
If you compare waterless coolants to a standard 50% water coolant then yes, the waterless coolant is probably better.

However in high performance engines there is no need for anti freeze additives and only a very little amount of corrosion inhibitors are required - as such it is not uncommon to have 95% water which is most definitely better than any waterless coolant I know of.

So, you mean that a water based coolant is better than a waterless on hot conditions??

Water has higher specific heat and probably works better for cooling, the waterless coolant is probably good enough.

Thanks! I thought waterless coolants were better

[63l8qrrfy6]

If you want to use them in your road car they probably are!

[PlatinumZealot]

Water is the best coolant because of its heat capacity and boundary layer properties.

We already have a whole topic on this years ago.

f1 coolant is pretty close to pure water. They simply run at higher pressures to keep boiling from happening.

[LMVG_2]

I remember this comment by Wazari in 2017 regarding Illien's involvement with the Honda PU. Spec 4 was supposed to be deployed in the McLaren in Japan (?) but kept being pushed back. As a residual of McLaren deciding to divorce Honda, Spec 4 never made it into a McLaren, and (if logic follows) instead became the foundation of their 2018 PU. Before Spec 4 there was Spec 3.6, 3.5, 3.4. Spec 4 was labelled Spec 4 around here because it was the first iteration to be designed solely by Honda. If this iteration of the PU enjoyed small success, and was not in any way Illien designed, I find it hard to believe that Illien is having a direct influence on the PU now.

The new "Spec 4" in the pipeline is NOT an Illien designed PU. He had nothing to do with the upcoming PU. This is a "team wazari" designed ICE, PU. Rumor has it that Illien has seen and blessed this configuration PU but I would be quite surprised if this is true. Sometimes I just want to wrangle these journalist's necks.

[...] Illien/Ilmor have been working with Honda since early 2017 and still are working together.

[Snorked]

Japanese publisher made a special edition magazine celebrating Honda's win in Austria - looks to feature an interview with Asaki and Honda Jet about the PU.





http://www.as-books.jp/books/preview.php?no=7128

Hope somebody can translate.

[roon]

f1 coolant is pretty close to pure water. They simply run at higher pressures to keep boiling from happening.

Sorry to post this grim image, but notice the color of the fluids. Oil or coolant? Seems to be two colors in the photo, one transparent, one ochre. I dont know how big the oil coolers were in 2016.

[PhillipM]

Doesn't tell you much, all the teams run dye packs and UV tracers in various oils and coolant system so they can tell immediately what a leak is from.

[Wazari]

Sorry to post this grim image, but notice the color of the fluids. Oil or coolant? Seems to be two colors in the photo, one transparent, one ochre. I dont know how big the oil coolers were in 2016.

https://cdn-1.motorsport.com/images/amp ... -crash.jpg

The gold colored liquid was coolant. There are several reasons why the specific coolant is used in the current PU, but the three major factors are vapor pressure, cylinder head/combustion chamber temps with regards to vibration and fuel consumption.

[Wouter]

[...] Illien/Ilmor have been working with Honda since early 2017 and still are working together.

Could you tell me your sources @LMVG? Do you have a link where I can read that :
Illien/Ilmor have been working with Honda since early 2017 and still are working together?
Thanks in advance.

[amho]

Sorry to post this grim image, but notice the color of the fluids. Oil or coolant? Seems to be two colors in the photo, one transparent, one ochre. I dont know how big the oil coolers were in 2016.

https://cdn-1.motorsport.com/images/amp ... -crash.jpg

The gold colored liquid was coolant. There are several reasons why the specific coolant is used in the current PU, but the three major factors are vapor pressure, cylinder head/combustion chamber temps with regards to vibration and fuel consumption.

Does engine designer try to run coolant fluid as hot as possible (up to cylinder head material resistance) to minimize thermal losses?

[stevesingo]

I suspect it will be a balance of high coolant temperature for in cylinder thermal efficiency and better heat rejection from the radiators against the fatigue strength of the materials at elevated temperatures and knock resistance.