#23966 - 03/01/2001 04:54
Re: AR coated screens
[Re: tfabris]
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carpal tunnel
Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
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Jaguar have been experimenting with this one for about the last three years, combining it with an IR night vision system and HUP display.
Don't count on it being in the shops any time soon - you know what Jaguar's record for getting product to market before the Ford takeover was like.... One of the few remaining Mk1 owners... #00015
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#23967 - 03/01/2001 05:29
Re: AR coated screens
[Re: schofiel]
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addict
Registered: 19/08/2000
Posts: 588
Loc: England
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I dunno. I never thought a simple question like mine about AR screens would have transmogrified into it's current discussionary state. Anyway while we're on the subject of Norton rotaries didn't the race bikes prove to be quite successful? They also used the engine in some police bikes (called the "Interpol II" I seem to recollect) and in a very expensive road bike called the F1. They should have marketed the bike at a lower price so that they were competitive with the Japs, like Triumph have done so successfully. They might have survived. This might be oversimplifying their problems but it's a nice thought.
beaker
12 gig blue
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32 gig MKII (various colours) & 30gig MKIIa
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#23968 - 03/01/2001 09:59
Re: AR coated screens
[Re: tanstaafl.]
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old hand
Registered: 12/08/2000
Posts: 702
Loc: Netherlands
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In reply to:
4) A general rule of thumb for fuel consumption in an internal combustion engine lightweight enough to be used in an aircraft is one-half pound of fuel per horsepower hour. Figure 75% of max power at the claimed cruise speed of 350 MPH, that would
be 720 HP, which would require 360 lbs of fuel per hour or 54 gallons of fuel per hour, which works out to something less than 6.5 miles per gallon, about 40% of the mileage they are claiming. Their FAQ page strongly implies that the engines are
Wankel-type rotary engines. These engines have never been known for fuel economy.
look here for a reply by Dr Moller himself
for more stuff look hereFrank van Gestel
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#23969 - 03/01/2001 13:24
Re: AR coated screens
[Re: beaker]
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carpal tunnel
Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
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didn't the race bikes prove to be quite successful?
Yes, they raced a number of seasons with relatively little improvement between seasons; they were basically road bike engines with special carburation and race pipes. They stood up to the competition extremely well and lasted a long time under hard race conditions. I managed to sit on one at Donington years ago and was astonished at the size of the bikes; they were little miniature gems.
some police bikes (called the "Interpol II" I seem to recollect) and in a very expensive road bike called the F1
There were a number of road bikes, both air and liquid cooled. The aircooled ones were first trialled by Durham police, and I got to wheelie one (yup, a full-faired Jam sandwich). I managed this 'cos my rugby club team coach was a RT Sergeant and he "loaned" me it for 10 minutes. When I got out of sight I whacked open the throttle and the front wheel just shot into the air. Marvelous - but not if you're a traffic cop. They didn't buy any; one of the delights of these early bikes was that when you went onto full left lock, the tension in the harness that ran under the tank caused the connector to pull off the ignition switch, which cut out the engine....
Virtually the same bike was produced in a small batch for public sale before they began production of the liquid cooled ones. There were again fully faired police versions and road versions; the Army, RAC and AA bought quite a few. Then there were the race reps - the second one was announced as the F1, which was basically their last gasp; the company tried to get the manufacturer of the race framed version to produce them in bulk, but the company collapsed.
To be honest, it wasn't the kit that was the problem - it was the same old warhorse, bad management. They didn't re-invest in the right machine tools and skimped on production, so the bikes just gradually got worse and worse. Finally, the management team were caught in some dodgy share dealing and the whole thing fell apart. Although there were rumours that the (then still in development) new Triumph company would buy them out, it never happened.
I'd love to know who owns the manufacturing rights to the engine, as it was the real heart of the bike; I have never forgotton just how tiny the bikes were (about the size of a 400cc), the massive torque of the engine, and the almost vibrationless operation; there was no red line on the tacho, and if you opened the throttle it was like there was an electric motor there instead of an IC engine. What a wonderful, wonderful machine. One of the few remaining Mk1 owners... #00015
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#23970 - 03/01/2001 21:14
Re: AR coated screens
[Re: tanstaafl.]
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pooh-bah
Registered: 25/08/2000
Posts: 2413
Loc: NH USA
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Yes, but does it have a DIN slot?
-Z
just say you weren't paying much attention...
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#23971 - 04/01/2001 10:30
Re: AR coated screens
[Re: tanstaafl.]
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addict
Registered: 24/08/2000
Posts: 658
Loc: India
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Thing is they have built the subs already, not a conception so I guess they work.
#695 Mk2 BLUE 12Gig
Ask and I may tell you
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#23972 - 04/01/2001 10:58
Re: AR coated screens
[Re: jwickis]
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carpal tunnel
Registered: 20/12/1999
Posts: 31590
Loc: Seattle, WA
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Thing is they have built the subs already, not a conception so I guess they work.
I dunno about that. The site advertising those particular subs (the giant luxury-yacht size personal subs we discussed earlier in another thread) had only paintings, not photographs.
Yeah, they've made little tiny personal submarines, but Doug wasn't talking about those when he made his statement. ___________ Tony Fabris
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#23973 - 04/01/2001 14:12
Re: AR coated screens
[Re: schofiel]
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addict
Registered: 19/08/2000
Posts: 588
Loc: England
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In reply to:
I'd love to know who owns the manufacturing rights to the engine...
I believe there were two separate parties involved in buying Norton's copyrights. One bought the Norton name and another bought up the rights to manufacture the engines (I presume this would include the rotary unit). I think one of them was Canadian but I'm not sure which one it was. I know there have been some arguments between the two of them as to who has the right to do what.
I could of course be talking complete rubbish, but that's what I seem to remember happened.
Wheelieing a police bike eh!! you naughty boy ![](/images/icons/smile.gif) . Good fun though I must say. I'm not a wheelie merchant myself but it sure does feel good when that front tyre (inadvertantly)leaves the Tarmac ![](/images/icons/smile.gif) . I've got a Yamaha FZR1000 Genesis which is quite well behaved unless the tank is nearly empty or you've got a pillion on board (hehe). beaker
12 gig blue
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32 gig MKII (various colours) & 30gig MKIIa
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#23974 - 04/01/2001 19:57
Re: AR coated screens
[Re: tfabris]
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carpal tunnel
Registered: 08/07/1999
Posts: 5546
Loc: Ajijic, Mexico
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I was under the impression that it would be a sort of a lifting-body design.
Looking at the admittedly beautiful and curvaceous shape of that aircar, I see very little in it that would generate any lift. To get lift, you need some sort of airfoil shape. This is always more efficient (in terms of drag) than powering a flat surface at an angle of attack sufficient to provide enough lift to remain airborne. The term lift/drag ratio refers to how much drag you incur for x amount of lift. Generating lift causes induced drag that, while not really the same as pure aerodynamic drag, still requires energy to overcome. The more efficient a shape that a wing (or lifting body or, for that matter, a brick) has, the less power it takes to generate the lift required to remain airborne. I see lots of drag compared to the amount of lift in the Aircar's design.
tanstaafl.
"There Ain't No Such Thing As A Free Lunch"
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#23975 - 04/01/2001 20:11
Re: AR coated screens
[Re: fvgestel]
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carpal tunnel
Registered: 08/07/1999
Posts: 5546
Loc: Ajijic, Mexico
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look here for a reply by Dr Moller himself
Well, somebody else asked pretty much the same questions I asked, with pretty much the same logic. I did not find Dr. Moller's responses to be all that informative.
Unless that Aircar shape is somehow generating enormously more aerodynamic lift than it would appear in the picture, I remain skeptical. His claim that "...At 25,000 ft. the thrust required for optimum cruise speed is only 66 lbs. from each nacelle..." would imply that he is generating more than 2100 lbs of aerodynamic lift in some very thin air.
But, who am I to argue? Dr. Moller is an aeronautical engineer. I'm a guy with a (non-current) pilots license looking at a picture of an airplane. I have to think that, unless this is a total fake designed only to defraud investors (and please note I am not saying that is the case), he certainly knows more about aircraft design than I ever will.
tanstaafl.
"There Ain't No Such Thing As A Free Lunch"
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#23976 - 04/01/2001 20:41
Re: AR coated screens
[Re: schofiel]
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carpal tunnel
Registered: 08/07/1999
Posts: 5546
Loc: Ajijic, Mexico
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with an overall weight of 35 lbs for the race engines. I can't remember the specific BHP figures, but they were generating the same shaft outputs (and higher) than 1,000 cc bikes
OK, that would work out to be about 2.5 HP per pound, about what is being claimed for the Aircar engines. But that is maximum, peak power, and even at a 70--75% cruise setting, would not be sustainable for uninterrupted hours at a time. It's been a while since I was really up on rotary (Wankel-type) engines... but I seem to recall problems with apex seal failures under heavy sustained loads as are typically encountered in an aircraft environment.
Norton specifically marketed the engine for lightweight, airborne applications, including drone engines and unmanned surveilance aircraft.
Yes, but not at anything approaching 120 HP rating, I suspect. A typical aircraft engine (Lycoming, Continental, etc.) puts out power in the neighborhood of about 1/2 horsepower per cubic inch displacement. Compare that to something like a Honda S2000 engine which puts out something in the neighborhood of two horsepower per cubic inch -- four times the specific power output. So why are regular aircraft engines so "inefficient"? Because they have to operate at 75-80% of their maximum output for hours on end, and 100% of maximum during takeoff. They have to keep the stresses down to keep the longevity up (and even so, they must be overhauled after each 1000 hours of use) which means big cubic inches, little horsepower. Small, highly efficient engines are not normally suitable for light aircraft use.
They have excellent fuel economy and low weight - the road bikes they powered regularly returned around 34-40 mpg
[Sarcasm]Whoopee! A 350 pound motorcycle, operating at (on average, probably) 1/3 to 1/2 maximum power output, on the ground (no need to waste power generating lift) at speeds averaging less than 1/4 the speed claimed by the Aircar and with about 1/5 the gross weight and maybe 1/10 the frontal area can get more than twice the claimed mileage of the aircar. I'm not impressed.[/Sarcasm] ![](/images/icons/smile.gif) I'll bet that on a measured economy run averaging, say, 80 miles per hour, that a Honda Insight with two passengers and luggage, would do better than that motorcycle. (The Honda would pull down 45-50 MPG at that speed, I belive...)
I think they are referring to the dBA (perceived loudness) levels on the ground.
Absolutely -- from a distance of 500 feet. That's not very far away, and those fans are going to make a good bit of noise, ducted or not, as the blade tips are approaching supersonic (they are small diameter, they have to turn them fast Let's see, they look to be a bit under three feet in diameter, call them 2.9 feet across. That's 9.1 feet around, they're turning them at 7200 RPM at takeoff, that's 65,520 feet per minute. Speed of sound is, what, 1100 feet per second, 66,000 feet per minute, that means those blade tips are turning at mach .993. Yep, that's pretty close to supersonic) and pretty damn noisy. Then, you have eight unmuffled (I assume unmuffled, otherwise you give up power) rotary engines running at maximum output. I'm sure you've heard an unmuffled rotary under those conditions -- hell, if they fired it up in Dover you'd hear it clear across the Channel in France. Now imagine eight of them at once... 65 decibels at 500 feet? No way. A typical office environment (with people conversing, air handlers blowing air around, etc.) is louder than 65 decibels.
PPS How did we get to be talking about rotary engines when we started out about AR screens?
Y'know, that's what I love about this bbs. It sometimes goes off on the most fascinating tangents!
tanstaafl.
"There Ain't No Such Thing As A Free Lunch"
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#23977 - 05/01/2001 02:01
Re: AR coated screens
[Re: beaker]
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carpal tunnel
Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
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Hmmmm..... That's interesting, because it means there is still a chance that someone's making spare parts, or that the engine could still be manufactured. I am not too upset about the Norton name (I should be). Still, now I can go out and research it a bit. Incidentally, I picked up a recent book covering the entire history of the Norton rotaries, so if anyone's interested, post here and I shall post the title and publisher details. It's an excellent little book, and very interesting.
As regards the wheelie... Well, it's a fair cop, guv. I confess it was accidental - I was just not expecting it. At the time I was riding a Guzzi Le Mans which had all it's weight forward - absolutely no way could you get the front end off the ground (well, not strictly true - I did see someone stand on the seat of a T3 with cow-horn bars yank the bike off the ground, but he was really trying ![](/images/icons/smile.gif) ) - I opened the throttle on the rotary expecting both the same weight bias, and the same throttle spring resistance (MISTAKE!!) and found both to be rather lighter than expected. Ooops....
One of the few remaining Mk1 owners... #00015
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#23978 - 05/01/2001 02:48
Re: AR coated screens
[Re: tanstaafl.]
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carpal tunnel
Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
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I seem to recall problems with apex seal failures under heavy sustained loads as are typically encountered in an aircraft environment
Loaded seal failures were very much a common problem with all early rotaries; Norton worked long and hard on sorting this out. They were absolutely focussed on this as their major selling point was to be engine longevity and reliability. One of the early air cooled prototypes ran continuously for 24/7 for over four years without stopping. During this run, the engineers didn't bother opening it, but stopped it occasionally and stuck in an opthalmoscope to have a look at the crank and seals. No wear was observed - when the company stopped the trial and pulled it down, they were pretty surprised to find that they had no need to replace anything and it went back together after the crank was crack tested. For a while the engine was in the company museum, with just the measured number of crank rotations on display in front of it.
Also, don't forget we're not talking about the rotaries of the late 60's/early 70's (DKW, NSU, Mazda) - this engine design began life around 1965 in a seperate research group that survived the NVT collapse in '72. They were developing various forms of the engine for almost 20 years. They hold(held?) many patents on the engine, and a significant amount of their work was cross licensed by Nissan in the 80's to improve their own car engines (Norton and Nissan were pretty much alone in persisting with the design, with good results).
Small, highly efficient engines are not normally suitable for light aircraft use
...Except when the plane is going to get a SAM 7 up the pipe, in which case so long as it reached the target, it wouldn't matter so much
No, I know what you mean about loading and stress levels; but don't forget, the engine is radically different from reciprocating piston engines - the big cubes, low power argument is not directly applicable here. The crank was a short, single cast piece, and the rotors span epicyclically around it to reduce crank flex. The engine was a narrow sandwich of a pair of combustion chamber cavities, and so the crank was absolutely rigid. The crank bearings were just great big plain bearings, even on the race bikes! In fact, the rigidity of the engine on the race bikes turned out to be a problem - they used it as a stressed member in the frame and the resulting frame design was remarkably minimal. When they took it out on the track, the frame had such little flex, that the tyres could not cope with the cornering stress the bike could deliver. The most frequent observation of the race press at the time was "yet another tank slapper" as the tyres rapidly gave up the ghost half way through the race. One of the riders was rather a big bloke (Trevor Nation) and observed that the subframe they bolted onto the back of the frame to carry the seat used to bend about an inch or so when cornering, which moved the centre of gravity and destabilised the bike as the rider moved out due to centripetal force....
As I described, the long term engine ran for four years without a service. I have no idea what engine speed it ran at, or what percentage of output power, but it was definitely reliable.
those fans are going to make a good bit of noise, ducted or not, as the blade tips are approaching supersonic
Although I agree with this argument, you are assuming the use of conventional propellers inside the ducts. NASA researched a new form of multi-blade prop which was designed to prevent a leading edge causing the shock wave associated with close-to-mach speeds. They are effectively conical spirals with odd numbers of blades, designed to operate in ducts - so before you ask "why wasn't this built into fighter jet airfoils?" it has to be ducted to work successfully; or "why not in the guts of jet engine compressor structures?" it is not suited to multi-blade compressor application (for various reasons). When they got it working (I think it was the JPL did the work), they were proposing turbo-prop engined (eh? Lo-tech!) delta wing aircraft with ducted fan engines that could hit mach 1. Quite an interesting development; haven't seen a damn thing about it since I read the article - but the fan designs (if that is indeed what the Moller is using) were incredibly quiet and fuel efficient. I'll see if I can turn up the article (it was in OMNI years ago, and I might have kept it), but don't hold your breath!
One of the few remaining Mk1 owners... #00015
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#23979 - 07/01/2001 14:43
Re: AR coated screens
[Re: schofiel]
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carpal tunnel
Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
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Eerrr.... As the observant of you may have noted, I must have been drinking stronger red than I thought; when I said Nissan Motors, I did of course really mean Mazda, who produced the rather excellent RX-7 Sports. Sorry about that...
For those of you really interested in one of the very last ones, there's a pre-registered one that I know of with only delivery mileage at a nice price. Drop me a line and I'll pass on the details. They also have a lot of used, low-mileage Miatas... One of the few remaining Mk1 owners... #00015
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#23980 - 07/01/2001 15:56
Re: AR coated screens
[Re: schofiel]
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pooh-bah
Registered: 25/08/2000
Posts: 2413
Loc: NH USA
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For those interested in the rotary engine, I believe Mazda is going to be coming back out with a rotary based vehicle within 1-2 years. I heard this at a meeting I was at with Mazda, but don't remember any more details.
-Zeke
just say you weren't paying much attention...
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#23981 - 08/01/2001 16:49
Re: AR coated screens
[Re: Ezekiel]
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addict
Registered: 09/06/1999
Posts: 483
Loc: Guernsey
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I seem to remember that they had a Rotory engine running on Hydrogen in some MX-5 demonstrator.
Apparently a Rotory engine is good with hydrogen, due to the intake and combustion taking place in different areas it has less problems with heat.
I might have imagined it though... =)
Jazz (List 112, Mk2 12 gig #40. Mk1 4 gig #30. Mk3 1.6 16v)
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(List 112, Mk2 42 gig #40. Mk1 4 gig #30. Mk3 1.6 16v)
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#23982 - 27/03/2001 08:03
Re: AR coated screens
[Re: tanstaafl.]
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carpal tunnel
Registered: 18/01/2000
Posts: 5683
Loc: London, UK
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Unless that Aircar shape is somehow generating enormously more aerodynamic lift than it would appear in the picture, I remain skeptical.
See here or here (which the previous links to).
Roger - not necessarily speaking for empeg
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#23983 - 27/03/2001 10:15
Re: AR coated screens
[Re: schofiel]
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old hand
Registered: 20/07/1999
Posts: 1102
Loc: UK
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I missed this thread earlier. (Hey, I'm not just slow on the uptake)
I can't remember the specific BHP figures, but they were generating the same shaft outputs (and higher) than 1,000 cc bikes, whilst being officially rated as 600cc capacity. A damn good engine design.
The engine was, from memory, 588cc in swept volume and produced approximately 115BHP as standard. It was possible to tweak them pretty severely, to well over 150+BHP. I lusted after one of these things for years during my light hovercraft days, but never managed to get one.
The motorcycle racing industry was somewhat divided on their liking for the things, and at one point an attempt was made to classify them as a 1176cc engine, since wankel designs have the rotor turn twice during a complete power cycle, because some people wanted to get them out of the sub 1-litre category due to the competition.
An interesting fact: in the early 90s sometime, when they were actually making the things, they had sold something like 8 time as many engines as bikes with engines, mostly to people with microlights, etc. There are even some light aircraft still flying with the things in. The cost of the engine was around £3000 a unit, too high for me.
Patrick.
Opinions expressed in this email may contain up to 42% water by weight, and are mine. All mine.
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