Topic: Oil cooler?

[FuZZie]

I was out in low 50(f) weather on Sunday and ran in the 145-165f range.

If you can always measure cylinders 2+3

 if you stand in front of your bike and look at the engine 2+3 are flanked giving maybe 1/3 less cooling area due to being in line.  Also notice the front wheel and fender,  they would be causing some weird air flow that may well be directing air away from 2+3 or at least foiling the flow.

I have no backup, no proof... I can only look at the front of the bike and try to guess, still I'd bet more motors fail with cylinder 2+3 that 1+4.....

[FuZZie]

You can find the temp info @ http://www.thelubepage.com/learn/lube-notes/lube-notes-synthetic-versus-petroleum-oil?showall=1 the chart shows the oil failing before the boiling point of water.

Water does not have to boil to evaporate, only be exposed to air at less than 100% humidity/saturation.  The emulsion does have to reach a temperature that allows water separation from it's trapped position in the viscous emulsion.

Temperature - An elevated temperature accelerate the water separation by increasing the probability of the water droplets to collide and decreasing the viscosity of the continuous phase.

Oil viscosity does thin with raised temps and this helps allow the tiny water bubbles to collect into bigger ones that can rise to the surface for evaporation, rather than be completely surrounded by the oil.  Higher temps, thinner oil, more water droplet movement to where it can evaporate.

An emulsion is water frothed into a viscous oil, where it becomes trapped and unable to move.  In the SOHC4 this looks like brown, tan or white mayo, (which is also an emulsion).

You are correct sir, but inside crank is a bit of a closed loop wouldn't  that leave a large percentage of said evap back in the oil?

[TwoTired]

You are correct sir, but inside crank is a bit of a closed loop wouldn't  that leave a large percentage of said evap back in the oil?

As I understand it, water gets inside the crankcase via piston ring blow-by (ingested via the air filter inlet and the outside humidity level), and any vent to the outside atmosphere.

Once inside, condensation can form on the engine walls during the engine cool down period.  It's the same thing that happens to the outside of a cold beer glass, only the temperatures are reversed.  The condensation trickles down the crankcase sides into the oil supply, where thrashing it around on the next start up creates an emulsion.  If the oil doesn't get to a sufficient temperature and stay there for a long enough time for the water droplets to evaporate, then the water content increases upon each cool down cycle, and you see the mayo collect on the coolest parts of the engine unit internals.

The hated-by-some engine breather system also applies a lower pressure inside the crankcase.  If you lower the pressure enough, water will boil at room temperature.  At any rate, lowering the pressure increases the evaporation rate of water when and if the water droplets stop being surrounded by a viscous oil.

As applied to oil cooler systems the oil emulsion gets distributed throughout the entire oil system.  If there is no by-pass valve, the oil keeps being cooled, and may in certain circumstances, not allow the complete release of water in the oil.  If the oil cooler thermostat is closed, water can be trapped in the cooler itself, and can't circulate unless the oil temp is allowed to rise above the thermostat trip point.

Water does react with the organics contained in the oil, to form amino acids.  As you may expect, acids dissolve metals at a rate determined by their pH level, quantity, and exposure duration.  This erosion would be over and above any friction induced metal losses wherever the oil is allowed to circulate or stagnate.

I hope I explained this adequately.

Cheers,

[dave500]

I hope I explained this adequately

off course,,its all on page three million of your book.

[FuZZie]

Your explanations are good, I understand them. 

If the oil doesn't get to a sufficient temperature and stay there for a long enough time for the water droplets to evaporate, then the water content increases upon each cool down cycle, and you see the mayo collect on the coolest parts of the engine unit internals.

The hated-by-some engine breather system also applies a lower pressure inside the crankcase.

Think I'd like to check into that breather system.
thanks

[Madman9050]

thanks for the info i had noticed that the engine seemed to get a little too hot in town from light to light based on the small amount of detonation i hear when i take off from long red lights this could be something else based on the fact that I'm new to these engines but temperature seems to be a factor

[TwoTired]

I hope I explained this adequately

off course,,its all on page three million of your book.

Must have been quite an ordeal to have been forced to read it.  Hope you heal soon.

[Terry in Australia]

Thanks Lloyd, keep this thread going mate, every time you contribute to an oil cooler thread I end up with several orders, so apart from recommendations from members here who have fitted and used my adapters, you're my best salesman!

Sadly the "profits" that I make from my adapters barely cover the cost of materials and postage, not to mention the $10K (+) that I invested in my lathe and mill, so I can't financially contribute to your public solicitations for money for your home spun oil cooler testing device, but as a sign of my appreciation for the continuous flow of customers you send my way, I'll be more than happy to test your device under more extreme "real world" conditions this summer, than you're capable of producing in your garage "laboratory", free of charge, of course.

I'm also glad to see that you now recognise that Honda offered an optional oil cooler kit for the CB750, along with a dual front disc brake conversion, steering damper, etc, all good performance mods that many SOHCer's here have fitted to their bikes, and of course, there are many SOHCer's here who have modified their bikes to produce performance well in excess of the old CR's moderate HP figures, so it's good that the above mentioned items are still available, albeit, after-market.

Like many members here, I'm an avid Post Classic Motorcycle racing fan, and I regularly attend race meets where I'm happy to see that Honda SOHC4's are very well represented, and of course, all of these bikes are fitted with oil coolers, which you'd expect on high performance bikes being ridden fast and hard. 

I'm no engineer of course, (and neither are you I'm guessing, or you wouldn't be soliciting donations from fellow forum members) so I'm not sure what you're attempting to achieve with your makeshift test rig, can you give us all a brief on it's purpose, and how it'll differ from commercially available equipment used by real engineers? Anyway, keep up the good work mate, and thanks again for the continued business! Cheers, Terry.    

[dave500]

can you give us all a brief on it's purpose

thats on page two million one hundred and fifty terry.

[Deltarider]

You can find the temp info @ http://www.thelubepage.com/learn/lube-notes/lube-notes-synthetic-versus-petroleum-oil?showall=1 the chart shows the oil failing before the boiling point of water.

Has any of you guys seen Dr. Watson's certificates?
I doubt the value of that scheme that limits extended use of petroleum oils (hard to find nowadays btw) even under 100⁰C. Never heard of that before and I wonder where it comes from. Maybe certified Dr Watson refers to petroleum oils 70 years ago

[Terry in Australia]

can you give us all a brief on it's purpose

thats on page two million one hundred and fifty terry.

Ha ha, I love a good book Dave, especially when I'm trying to fall asleep!

[MCRider]

"C. I don't feel that most of the forum actually wants an answer that doesn't fall in line with their preconceived opinion."
Lot of truth in that. Mirrors, anyone? 

Considering the tone and volume of your replies, you'd have to consider recusing yourself.

"something to point at"

Nothing wrong with that I maintian. These are just our toys, with rare exceptions.

[scottly]

The hated-by-some engine breather system also applies a lower pressure inside the crankcase.  If you lower the pressure enough, water will boil at room temperature.  At any rate, lowering the pressure increases the evaporation rate of water when and if the water droplets stop being surrounded by a viscous oil.

Once again, please provide empirical evidence of the pressure reduction produced by the breather system.

[mick7504]

Let me know if you need a copy of the other 9 volumes Dave. 

[dave500]

she will be right mick7504,,ive already worn out a pair of spectacles reading the foreword in volume one!