Primarily for general aviation discussion, but other aviation topics are also welcome.
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By Miscellaneous
#1787263
andytk58 wrote:The camshaft in a 912 sits in the bottom of the engine, so unlike an O-200 where its at the top.

ie, its unlikely the camshaft will be scraped dry by hand turning the engine as its drowned in oil, no?

I don't know the internals of the engine specifically, so don't have a definitive answer. However, I think the main concern is the oil naturally running off surfaces, such as the camshaft, where the engine has not been run for some time and then the engine being turned by hand.

I changed my oil just before lockdown and with the recycling centres being closed left the old oil in the hangar. I had drained it in to an old basin which I had left tilted and draining in to an oil bottle. I was surprised at how clean the basin was when I went to sort it out. IE how much oil had drained away.

Is it not also the case Lycoming and/or Continental recommend not turning the prop during periods the engine won't be run to minimise the likelihood of internal corrosion? Or is that just an old wife's tale? :D
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By TheFarmer
#1787265
I’ve held off until now, but there are a few things that have been said that are
complete nonsense on this thread.

Basically, Miscellaneous is correct.

What he’s saying is, if you need 89p for a loaf of bread and you pull out two 50p’s from your pocket amongst your loose change as you walk out the door and off to the shop, you really don’t need to know how many coppers are in there before you leave the house. I agree. He’s right.

However, if your oil tank is set up high (like on the firewall of a Kitfox), you DO need to gurgle, because all you can see is the coppers, and you need to see that the two 50p’s are there.

Misc, like me, has a lowish tank. When I check the oil and I see it’s on the dipstick, I know I’m safe to fly, and unless the oil angels have added an extra litre overnight, I know to 99% accuracy what I have. That’s good enough for me.

Blimey. Can’t you lot discuss something more interesting like ballistic parachutes.... :roll: :lol:
Miscellaneous, AlanC, Flyin'Dutch' and 3 others liked this
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By RichJordan
#1787448
bvq wrote:Here's another report of someone successfully hand swinging a Rotax but with unfortunate consequences:
https://assets.publishing.service.gov.uk/media/5422f971ed915d137400074d/Skyranger_912_2___G-CCXM_9-05.pdf


I owned that aircraft for a couple of years (after this incident).

Always imagined Bad To The Bone playing when I saw it in the hangar. Bit of a Christine vibe.
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By Miscellaneous
#1787451
Sounds a nasty one, at least he lived to tell the tale. :thumright:

Of course an accident whilst intentionally starting by swinging the prop is simply that, not Rotax specific and unrelated to gurgling. :D Even watching a n other hand swinging sends a shiver up my spine. :pale: Lack of experience, I guess, having only done it once. :D
By riverrock
#1787551
Miscellaneous wrote:Is it not also the case Lycoming and/or Continental recommend not turning the prop during periods the engine won't be run to minimise the likelihood of internal corrosion? Or is that just an old wife's tale? :D

Yes on Lycoming anyway - it uses splash lubrication (I believe) and hand turning doesn't provide the energy to let this happen, so you scrape away the oil if you hand turn the prop. This increases static corrosion if you don't start straight away and wear if you do start then. So don't hand turn out of habit.

I have never heard a comment about Rotax in this regards, but I've also never owned a Rotax. I suspect the different lubrication system, the dry sump and different materials would mean this isn't an issue on Rotax.
By Shoestring Flyer
#1787641
patowalker wrote:That is because ceramic coated aluminium cylinders do not corrode for lack of oil.


..and additionally with it being a sealed system there is also no air in there to cause corrosion anyway.
By oldbiggincfi
#1787642
Shoestring Flyer wrote:
patowalker wrote:That is because ceramic coated aluminium cylinders do not corrode for lack of oil.


..and additionally with it being a sealed system there is also no air in there to cause corrosion anyway.


Explain ! What fills the voids in an empty engine ?
Miscellaneous liked this
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By Miscellaneous
#1787646
patowalker wrote:That is because ceramic coated aluminium cylinders do not corrode for lack of oil.

The benefits of modern materials. :thumright: One of the advantages of the Rotax. :D

Shoestringlfyer wrote:..and additionally with it being a sealed system there is also no air in there to cause corrosion anyway.

Are you sure about that? :?
User avatar
By lobstaboy
#1787650
It's a four cylinder, four stroke engine. There will always be at least one valve open letting air into the combustion chambers. That's one of the reasons we were allowed "engine health" flights recently.
User avatar
By lobstaboy
#1787654
Miscellaneous wrote:@lobstaboy I think you may be misunderstanding the concept of a 'sealed' in this discussion. :wink:


What I'm saying is there are always going to be internal parts of the engine exposed to moist air. If they are steel they need oil on them to prevent corrosion.
Patowalker points out that a Rotax four stroke hasnt got steel cylinder liners, so not an issue.
The crankcase may be sealed, but that's all.
OK?
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