10/23 Raptor Video

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BoKu

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...Peter set prop to "flat pitch", oil level went up and light came off...
Interesting! Do I correctly understand that the change in oil level is because of the oil pumped into the pitch change cylinder in the prop hub? How much oil volume does it take to go from flat to coarse pitch? Based on the general aviation prop hubs I've seen, I would imagine that it's around half a quart.
 

Bill-Higdon

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I didn’t search for long, but at least from the factory it looks like the only sensor is low oil pressure and not low oil quantity. I’m not aware of any car that has a low oil quantity sensor, but I suppose PM could have installed one.
Toyota started back in the 80's putting oil level sensors on their vehicles, some of them like the one in my 87 Van are notorious for giving false low oil level indications. Also VW has what's called the Dynamic Oil Pressure Warning System which can be a pain in the rear.
 

Malish

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Right. But I don't think his oil sensor is a low level sensor. I thought it was a medium level sensor to indicate a leak.
He likely checked each preflight as always and silly to guess otherwise
Raptor Audi engine has standard "low oil level" censor and light (and that what Peter use). But Peter himself said that on that flight the oil level was BELOW "normal" level on preflight(engine has "deep stick"?), but he still decided to fly without adding some oil! In aviation no need for "low oil level" light - you can't add oil in engine in flight! Oil level NEED to be checked on every preflight with "deep stick"!
 

Malish

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Interesting! Do I correctly understand that the change in oil level is because of the oil pumped into the pitch change cylinder in the prop hub? How much oil volume does it take to go from flat to coarse pitch? Based on the general aviation prop hubs I've seen, I would imagine that it's around half a quart.
I did answered on this question above and remember aviation engines with constant speed props holding much more volume of oil then automotive engines.
 

flywheel1935

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Here's a thought. I admit I know bugger all about VP props, but I'm guessing that the oil that controls the prop (the dirty engine oil) is being pumped by the same oil pump that's feeding the engine?. Would it be possible that cycling the prop would then result in fluctuations within the oil feed to the rest of the engine??? Also PM has still not confirmed that the oil system was flushed out totally after his previous engine failure.
I posted this last Wednesday, going to get some lottery tickets next week !!!!!!!!!!:cool:
 

speedracer

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I didn’t search for long, but at least from the factory it looks like the only sensor is low oil pressure and not low oil quantity. I’m not aware of any car that has a low oil quantity sensor, but I suppose PM could have installed one.
If my Corvette is a quart low on oil I get a message "Add one quart of oil".
 

Bill-Higdon

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Slightly below "normal" can be ok if above " minimum" on a short flight.
On my airplane "full" will simply blow out the breather on to the belly.
Depends on engine some you can fill to the full mark on the dipstick no problem others anything above the add oil line gets "blown out of the engine. I had a 55 Chrysler Hemi that would do that
 

Mark Z

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I can’t remember the last time I looked at the car’s dipstick; when the id1OT light comes on it gets changed. Why isn’t there a light that gives you a countdown to the last start left in the battery?

I do remember PM installing a low level oil sensor.
 

gtae07

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GM has been installing low oil level sensors for many years now. My Yukon and my Corvette both have one. Frankly, as infrequently as people actually check a dipstick these days, I'd be surprised if ANY modern car does not have a low level warning feature.
The low oil light saved our Tucson one day. Idiot that changed the oil the last time didn't torque the drain plug properly; it came loose and dumped the oil after 500 miles.

Of course, wife then wrecked it a couple weeks later...
 

speedracer

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Those uppity cars like a Mercedes don't have a dipstick. They send you an email when they are low on oil.
Yes they do have a dipstick, at least mine does. It's about 4" long, just to fill the top of the tube up, I guess. To check the oil, you have to push buttons on the panel. My uncle has owned newer M/B's for 30 years or so. I told him about the mysterious dipstick. Five minutes later he had the hood of his car up to check. Bottom line.... he's NEVER checked his oil in 30 years.
 

Vigilant1

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New video just out from Ross:
EDIT: Have seen it now, a very clear summary of the project's aims and results to date.
IMO, to the extent the video covers the attributes of the plane and concept it is based on, it is a very useful and succinct analysis. I hope it attracts attention for the content in these areas, and that it serves to temper expectations and thereby reduce a lot of pain down the road.
 

BBerson

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He changed the "estimated" empty weight on the website from 1800 to 2300 lbs. (not 2000).
That still wasn't the more realistic goal of 2600 lbs that I had suggested at that time.
It's clear that every "estimate" on the website was irrationally optimistic. Whether his team was aware of the actual weights before the final weighing is not clear. I can't believe they assumed the scale weight of this research airplane was expected to weigh 1800 pounds.
I think first designers may sometimes be "irrational optimists".
 
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