Mike said
"Modern engines for cars are built way better than that. There's a
story about the early days of WW2 when Ford at Dagenham were asked if
they could build Roll-Royce Merlin's. They agreed to look at the
drawings and after 3 weeks rang Rolls and said we can't do it. The
Rolls guys said "tolerances too fine for you, eh?" The answer " no we
can't build crap that badly. ALL our pistons have to fit ALL our
cylinder bores - we can't hand select."
That story is as documented in "Not much of an Engineer" a RR story. RR
spend many weeks tightening all the Merlin tolerances so Ford could mass
produce the engine. Ford? I thought it was Packard or Griffin.
Also in the book was the calculation that a 1200 hp RR produced possibly 800
lb of thrust for the Spitfire, as did the first jet engines.....
Alan Wilson
Canberra
--------------------------------------------------
From: "Mike Borgelt" <[email protected]>
Sent: Friday, June 12, 2009 9:32 AM
To: "Discussion of issues relating to Soaring in Australia."
<[email protected]>
Subject: Re: [Aus-soaring] eh? Certified?
At 10:59 PM 11/06/2009, you wrote:
Mike,( I always like your posts, don't take offence out of hand!)
Firstly,
I don't understand your point, but I would like to thank you for the time
you spent putting it forward.
Typing is such a dreary, half baked way of communication.
Wayne,
The point was that a satisfactory engineering device whose characteristics
were known was unable to continue to be used because of an arbitrary
bureaucratic rule that the manufacturer had to "certify" it. The
bureaucrats could have simply decided that for motorgliders "uncertified"
engines could be used as they continue to be in ultralights. The result
was that a whole new set of problems on devices of unknown service history
was created resulting in unnecessary expense and hazard to owners.(better
the devil you know etc). These devices weren't even going to be better
technology - just the same old 2 stroke boat anchors with horrible
reduction drives and retraction mechanisms.
Secong,
What, ultimately is the answer, or an answer, or could be improved?
I have a deal of experience in manufacturing machinery and I could not fit
a
batch of doors to a helo that would all be the same, I don't know of
anyone
who could. The parameters are too flexible.
I guarantee the door made for the frame would not fit in Alaska, and if it
did, it would not fit in 3 months of helo use in Hawaii, simple
engineering
problem, currently no satisfactory all purpose fix.
The current answer is, unfortunately, build it substandard.
For a door that would mean the thing is overweight and loose fitting.
For an engine?
The problem with the helo doors wasn't that they didn't fit the hole in
the side of the aircraft, it was that when they locate the hinges and
latches they don't seem to use jigs.
Modern engines for cars are built way better than that. There's a story
about the early days of WW2 when Ford at Dagenham were asked if they could
build Roll-Royce Merlins. They agreed to look at the drawings and after 3
weeks rang Rolls and said we can't do it. The Rolls guys said "tolerances
too fine for you, eh?" The answer " no we can't build crap that badly. ALL
our pistons have to fit ALL our cylinder bores - we can't hand select."
This is all a factor of production numbers. Sports aircraft including
gliders are made in such small numbers and have little potential to kill
more than one or two people at a time, overwhelmingly the occupant(s).
What is the point of certification particularly when you "certify" a
prototype. This prevents timely introduction of bettter parts, design and
technology.
If I were to build an engine to power an aircraft (my dream aircraft
perhaps) it would be about 2/3 the size of today's current crop and have
about twice the output. Perfectly possible with todays standards.
No problem at all, really.
:-)
Ask the guys trying to use car engines in homebuilts. Possible, but a
minefield. See May 2009 Kitplanes for details.
Lycoming and Continental are doing fine thank you. Add modern fuel
injection and ignition systems and you won't do much better - for long
anyway.
Mike
Borgelt Instruments - manufacturers of quality soaring instruments since
1978
phone Int'l + 61 746 355784
fax Int'l + 61 746 358796
cellphone Int'l + 61 428 355784
email: [email protected]
website: www.borgeltinstruments.com
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