Valve cover schmutz

Stromgriso,
It will be very interesting to compare symptoms over time with our bikes fairly close together.
I think you give more beans than I do though.

Pete Roper wrote:

It is very likely that in cold weather you'll always get mayonnaise in the rocker covers. They are right out in the airstream and well insulated from the heads themselves, even if you can get the oil temperature up the rocker covers will probably condense water out of the internal gasses in the crankcase.

Pete

Pete, with regard to your point, are we effectively chasing our tails here trying to fix this issue, that it’s simply a case of engineering design meaning condensation will always be present in the “cooler” parts such as the rocker covers etc? You’ve pulled apart a heap of Guzzi engines, and it would be interesting to know if you see the mayo effect in most (or all), or only in a limited few?

Most of them. All of them in the winter.

One of the major byproducts of combustion is water, there is always some blow-by past the rings so the glasses inside the crankcase will always be moist. Add in damp air drawn into the engine as it cools and it's always somewhat tropical in there!

The breather system can only purge the water if it is in its gaseous form and for that to be achieved the oil has to be above 85*C at the very least where it will begin to sublime off but ideally over 100*C with good through-flow in the breather system. Unfortunately Guzzi's breather systems have always been a bit of an Achilles heel and the fact that the 12 and 1400's run so cool due to the lack of a thermostat simply exacerbates the problem.

It doesn't seem to cause problems in the roller motors though somalthough it is less than ideal I don't tend to worry too much about it. It's easy to become too paranoid about things.

Pete

Thanks Pete. As it turns out, my thermometer oil dipstick supposedly arrives tomorrow, so I’m keen to log a bit of data (in a likely haphazard manner) just to see what sort of oil temps I’m running in what is mostly a reasonably temperate Melbourne climate. I’d be very surprised if the oil doesn’t get considerably hot when giving it the berries through the hills.......that bit isn’t really a concern. It’s more when it’s just plodding around the burbs on a lazy Sunday morning. That’s when I suspect she never really generates sufficient oil temps.

“And may the schmutz be with you...” Or with me anyway!

Received my black MG Cycle thermometer today. Looked a bit longer than the original dipstick when compared side by side, and at first I feared it was too long, as I could feel it bumping various bits as I was attempting to seat it, but it went in ok and screwed in fully without resistance (my GRiSO is a 2014 model with the deeper sump, hence I got the model that specified the pre 2015 GRiSO models). Likely head out for a ride this Saturday and get some preliminary temp data.

ecs wrote:

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Is this the right one?  Looks like 1 left.  Around USD$35

For what it is worth, this one works fine in a 2017 GRiSO.

This weekend I went to Indianapolis to visit Ratso & Chuck Stottlemyer. After the recent posts about oil temperature, what is ideal & what you need to be above to not get mayo created in the valve covers, I thought I’d instal the oil temperature dipstick back in the GRiSO for the weekend to see what my machine runs at.

On the 4 hour run there, air temp around 75 F, 24 C. Riding about 75 - 85 mph the dipstick stayed around the 120 C mark.

On the way back I got on the interstate to get out of sprawling Indianapolis quicker but got struck in almost stationary traffic before a construction area. After 10 minutes of this with the air temperature on the dash at 88 F, 31 C, I was dripping sweat in the full sun & riding gear. Looking down the dipstick was showing the needle had passed the 140 mark & was stuck as far as it could go. The bike was still idling in it’s usual lumpy way but I weaved my way off the interstate to the minor roads to get some air flowing over me & the engine.

That started me to thinking about what temperature would start to cause damage to the engine ? What would be indicating symptoms & what would have been the best course of action ?

Mind you Ratso, who is an aircraft engine mechanic had been filling my head with tales of oil starved jet engines coming apart. So I could just be dreaming up wild horror stories

As long as you're running full synthetic oil, you shouldn't have a problem with excessive temperatures causing the lubrication to fail.

Just my $0.02¢.

A few years ago I had a customer who left his GRiSO idling in the garage for a L-O-N-G time.

It got so hot that the tank couldn't vent fast enough and expanded to the point the fuel spigot melted against the head. It was within minutes, if not seconds, of failure which would of almost certainly resulted in a serious fire.

Luckily before that happened the phase sensor went tits-up killing the engine and I went and picked it up dragged it back to the workshop to investigate. The oil was so cooked it stank out the workshop for a week. I was certain that the motor would be mostly trash!

I stripped it to the crank and the amazing thing was that everything, I mean everything, was essentially within spec. Even the ring tension wasn't seriously compromised but I threw a new set in anyway. The amount of heat abuse the engine will take is astonishing!

That bike was eventually sold back to me and I sold it to my mate Dave who couldn't gel with GRiSO and then it was on sold to Greg in the Townsville push where it gets thrashed regularly in tropical heat with no ill effects.

Pete

Good to know. Thanks