Foaminess in residual oil in rocker assy

[brider]

When I pulled the valve covers off my Cal 2 last week to pull the heads and send them out, I noticed the residual oil floating around on the rocker assemblies was not clean, dark oil, but it had a milkiness to it that I wouldn't call normal. Would this be a valve cover or engine breathing issue, or is a bit of foaminess/milkiness normal due to the maelstrom of oil flying around?

[oldbike54]

 Not normal , sign of moisture in the oil , jokingly known as "mayonnaise" . Could be a breather problem , or the result of not getting the engine fully hot when started . Do you live in a wet climate?

 Dusty

[brider]

You might have nailed it on the "wet climate".

I'm in CT, and our winters DO have brief bitter-cold spells, but lately there's a lot of warmish, slushy raininess with mild temps.
 AND, the garage the bike is in does not have a sealed slab floor, so when it's foggy/rainy/warm and in the 40's, there is significant condensation inside the garage, coming I believe thru the floor. Only under those certain conditions, and I'd say that's happened 2 times so far this winter.

[oldbike54]

 Likely an oil change and a bit more care getting the engine fully warmed up every time it gets ridden will solve the issue . It just happens occasionally , wouldn't be too concerned .

 Dusty

[Wayne Orwig]

The engine blowby is where the moisture comes from, not from outside. Then the cool weather keeps the valve covers cold enough that you get condensation.

[Kev m]

In my experience that won't form with JUST the bike sitting. Little or no condensation occurs inside the motor when sitting even in that environment. Think about say your car being parked in the same environment with the windows closed. You don't get condensation in it even though there are vents.

That sort of condensation occurs during cool-down after engine operation, usually after it hasn't reached operating temperature. And it doesn't happen all at once, but a little bit time after time.

Unfortunately just reaching operating temperature later is not usually enough to get rid of it either, you often have to remove the covers and clean it out yourself.

[guzzisteve]

I used to tell customers that if you're not going 10mi don't turn the key, that's how long it takes to be fully warmed. UNLESS it's hot outside.

[oldbike54]

 True , the internal moisture is a byproduct of combustion , but since wet air takes longer to heat up and cool down it can and does effect how long the heating and cooling process takes .

 Dusty

[Kev m]

I used to tell customers that if you're not going 10mi don't turn the key, that's how long it takes to be fully warmed. UNLESS it's hot outside.

In PA winters on my Jackal I found that stuff even after all trips were 20-30 minutes.

I actually think what stopped it more than run time (for me) was using a Guzzi barn door windshield in the winters.

Once I installed that I never saw mayo again come spring.

[Dharma Bum]

Kev - Could you elaborate on that?  Did putting the barn door screen on enable you to ride it farther in the cold?

[brider]

In PA winters on my Jackal I found that stuff even after all trips were 20-30 minutes.

I was GOING to say all  my trips are over 10 mi, but they're no more than 20 min, that's about how far I work from home; maybe 12 mi one-way.

So if that's the case, should I do ANYTHING to alter my routine? I don't think warming up in the driveway for an extra 5 min is a good idea, or driving an intentional 10 mi to/from work.

[Kev m]

Brider, yeah, I'd take the long way to and from work if it were you.

Dharm, no my commute was the same, but I think the huge barn door shield blocked some air to the motor, maybe just enough.

[lucian]

Get yourself an oil dipstick thermometer and monitor the operating oil temps. If it isn't showing 100 degrees c or higher your oil is not getting hot enough to  cook off the moisture so it will accumulate over time.  I  find that  in cool damp weather it sometimes requires cutting down the airflow through the oil cooler with a shroud to get the oil temp up unless your really working the motor hard. Your motor should have an oil thermostat built in that my griso doesn't ,but it's still nice to have a way to actually see what the oil temp is and adjust procedures accordingly.

[SmithSwede]

Most people don't think about this, but our gasoline powered internal combustion engines are water makers.

They create about a gallon of water for each gallon of gasoline they burn.  So if the conditions are right, you are going to get water in places you don't want. 

Next time you fill up your tank with gasoline, visualize filling it with water from a garden hose.   Because that's about how much water you are fixing to create.   

[Sasquatch Jim]

 You are probably making short trips using synthetic oil.
 If you must make a lot of short trips, use dinosaur oil.

[Mean Mr. Mustard]

You are probably making short trips using synthetic oil.
 If you must make a lot of short trips, use dinosaur oil.
[/quote

Just curious. Why would a different type of oil make a difference?
Mario

[Chuck in Indiana]

You are probably making short trips using synthetic oil.
 If you must make a lot of short trips, use dinosaur oil.
[/quote

Just curious. Why would a different type of oil make a difference?
Mario

I think what Jim's talking about is changing it much more often.

[Kev m]

I think what Jim's talking about is changing it much more often.

It has nothing to do with that, unless one is planning on changing it every month or two in winter.

It's not like moisture builds up in the oil all summer, spring, or fall, assuming one does generally get the motor to operating temperature.

[Sasquatch Jim]

  Let me clarify.  Synthetic oil is more likely to create cottage cheese under your rocker covers due to condensation.
 If you short trip, you engine does not get hot enough for long enough to boil out the condensation so you get cottage cheese.  I know this from my own experience with 2 Guzzi.
 When I changed to Dino oil the cottage cheese stopped.  Either the Dino oil doesn't make the cheese or it boils out the water more easily.  When I rode the Guzzi on longer trips I didn't' have the problem.  Good Dino oil in those days was about a dollar a quart.  That is much cheaper than parts.
 That cheese will slow down the return of oil to the bottom of the engine and enough could plug the passages up.
 I have not used synthetic oil in the last 13 years because of this.
 Now that I am disabled, all my riding is short trips.

[Kev m]

In fairness I use nothing but synthetics, so I can't confirm or deny. Though I can say the Jackal is the only one that ever showed any mayo and I managed to get it to stop doing that even with synthetics.

[pyoungbl]

Air cooled engines will, by design, shed heat really well in order to cope with hot weather.  Unless you have an oil cooler with a thermostat that same cooling will mean that the engine struggles to get up to a good operating temperature when it's cold and damp.  Even on a 70F day my Ducati would show LO temp if I was riding in the rain because that rain was also evaporating so much engine heat.  OP mentions being in a cold and damp location.  I suspect he is not getting the oil up to the required 212F or 100C needed to boil off the excess moisture.  An oil temp dip stick will tell the story but even an IR thermometer would do.  Take a temp reading from the valve cover.  I bet it won't show much over 160-180F after a 20 minute commute.  That was also my experience with my Stelvio.  I'd recommend a longer ride at least once a week.  By longer I'm thinking at least an hour, two would be even better.  A little mayo in the valve cover is not a big deal (IMHO) because that's likely to be the coldest spot in the entire lubrication circuit and the valve covers are getting a shower of oil rather than the high pressure seen at the crankshaft.  The situation starts to get critical when that mayo is in the crankcase where the oil pump is sending high pressure oil to the rod bearings.

*Note, I am not an engineer. 

[brider]

Very interesting discussion.

I use dino oil.

I am convinced now that my lifestyle that limits how far and when I can ride is the culprit; The minimal-effort idea of adding an hr+ ride-a-week to my routine is the most appealing to me.

Thanks, guys!

[SmithSwede]

Yep, that's one of the downsides of an air-cooled engine.   Its surface area for cooling (fins) needs to be large enough to shed sufficient heat when running 85 mph all day in 125 degree ambient temperatures around in Death Valley.   But that same area is too large when it is cold, and certainly when it is cold and exposed to rain.   

I've always wondered if there isn't some way to work around this problem.   For example, why not fit a relatively coarse burlap cover to the cylinders, so they get some air flow, but not nearly as much as the unobstructed cylinders would get?

Or maybe wrap a suitably sized thickness of rope around the cylinder in the valley between the fins, so that the effective depth of the fins is less?  Or wrap some rope around the valley of some of the fins, but not all of them?

To my knowledge, this stuff is never done, even back when air cooled engines were used in military applications in very cold conditions.   I'd love to know if I'm wrong about that, and there were some arguably practical "warmer" type devices.

I have heard that it wasn't unusual to drain the oil from air-cooled radial aircraft engines so that the oil could be heated up in the hangar and then poured back into the engine prior to starting.  But I think that was more to be able to start the engine with a non-multi grade oil.

My hunch is that as a practical matter, this theoretical disadvantage is not that big a deal, and not worth tying to fix it.   Yeah, the air-cooled engine will run too cool at times.   No big deal.  Get it hotter occasionally.  Or change the oil a bit more often.   

[Kev m]

OP mentions being in a cold and damp location.  I suspect he is not getting the oil up to the required 212F or 100C needed to boil off the excess moisture.  An oil temp dip stick will tell the story but even an IR thermometer would do.  Take a temp reading from the valve cover.  I bet it won't show much over 160-180F after a 20 minute commute.

<snip>

A little mayo in the valve cover is not a big deal (IMHO) because that's likely to be the coldest spot in the entire lubrication circuit and the valve covers are getting a shower of oil rather than the high pressure seen at the crankshaft.  The situation starts to get critical when that mayo is in the crankcase where the oil pump is sending high pressure oil to the rod bearings.

Just to be a tad pedantic about it, water evaporates all around us, all the time, at temperatures much lower than boiling point. I don't believe the oil NEEDS to reach the boiling point of water for it to shed moisture, though it does happen faster as you approach it.

The ONLY bike I've ever had mayo on was the Jackal which was particularly well cooled and is more similar than not to the OPs bike.

I would still worry about mayo in the valve covers of a big-block 1100 Cali (can't say for sure about a Stelvio) simply because:

1. Once emulsified it may not separate and boil off again on its own. I found mine months after winter (when doing a routine valve adjustment).
2. The crankcase breathers are real close to that point and if the mayo plugs that you might have worse problems. Though I'm not sure it would be strong enough to cause worse problems you never know, it might just cut down on the breathing enough though to do so.

[Mean Mr. Mustard]

  Let me clarify.  Synthetic oil is more likely to create cottage cheese under your rocker covers due to condensation.
 If you short trip, you engine does not get hot enough for long enough to boil out the condensation so you get cottage cheese.  I know this from my own experience with 2 Guzzi.
 When I changed to Dino oil the cottage cheese stopped.  Either the Dino oil doesn't make the cheese or it boils out the water more easily.  When I rode the Guzzi on longer trips I didn't' have the problem.  Good Dino oil in those days was about a dollar a quart.  That is much cheaper than parts.
 That cheese will slow down the return of oil to the bottom of the engine and enough could plug the passages up.
 I have not used synthetic oil in the last 13 years because of this.
 Now that I am disabled, all my riding is short trips.

Interesting.  One small correction if I may. 
Wouldn't that be Ricotta cheese?