From: hotrod@dixie.com (The Hotrod List)
Subject: Re: Engines of Yore
Date: Mon, 11 Jan 93 21:03:07 GMT
Organization: Dixie Communications Public Access.  The Mouth of the South.
To: hotrod@dixie.com
Reply-To: hotrod@dixie.com
Posted-Date: Monday, Jan 11 16:03:04
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X-Gifs-To: met@sunset.cse.nau.edu
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-> in Bad Oeyenhausen, Germany.  The Megola had a five cylinder
-> 600cc radial engine in the centre of the front wheel.
-> A single carburettor was fitted on one hub. No clutch,
-> no gears, and to drop the final drive ratio, you put
-> on a bigger front wheel !

 Yeah, I saw a brief article on it once, though I'd forgotten the name.
"Look, ma!  No clutch!  And no braaaaaaaaakesssssss......"

 The most amazing thing was how late it was developed - 20 years after
motorcycles had reached the basic configuration we use today.


-> There are three examples left.  Two of them are in museums in
-> Germany.  The one I saw had some fresh-looking grime on it so
-> it's probably still a runner.

 That's good.  All antiques should be functional.  <grin>

 I've been reading a pre-WWII book on auto mechanics, and it has a
thorough discussion of how to pour and fit Babbitt bearings.  I'd always
thought that, y'know, you just flipped the engine over, took off the
pan, and poured it in somehow.  Nope.  First you get to chisel the old
Babbitt out, then you clean endlessly because any water or oil will make
the new metal bubble, then you clamp this wierd fixture across the main
web and put in a plug approximating the crank journal diameter (and
they're all different, do the thing is a "universal" fixture which
probably worked about as well as you'd imagine).  Then you heated the
Babbitt in your furnace and poured at red heat.  After it cooled, you
cracked the pouring fixture pieces loose and had this big wad of metal
(hopefully) stuck to the block, with fins, flashing, and drools of
escaped metal run down into the rest of the motor.  You got to spend a
while trimming off the excess, and then you got to repeat the entire
process for the rest of the bearings AND their main caps.

 Assuming you got through all that without Babbitting your foot or
setting anything afire, you got to fit the bearings.  In a large shop
you'd have a line boring machine available, much like large shops do
today.  A smaller shop might use a reaming stand and fixture.  If you
were in a small town, ye olde mechanic probably had to scrape the
bearings to fit.  This meant using metal scrapers, which were shaped
more or less like scalpels or midget fancy butter knifes, and carving
the soft Babbitt metal to a reasonable fit to the crank.  Once the crank
would actually go in, he'd use Prussian blue to find the high spots,
scrape, blue, scrape, etc.  Of course, scraping too much would require
starting over again, so he'd be very careful.  Oh, yeah, he also got to
cut the oil grooves by hand, too, to the pattern required by the auto
manufacturer.  Not cutting the grooves would be a bad idea, since most
Babbitt bearing engines used dippers and splash lubrication rather than
pressure oiling.

 Once he had about a 75% fit between the crank and bearings, he'd clean
everything off, bolt the crank in, and (if he was a perfectionist) would
lap the crank in by running it with an electric motor.  Then it all came
apart again so the rest of the engine could be assembled.  All in all,
it sounds like a full day's work, and one requiring a fair amount of
specialized machinery (and that's even assuming the crank didn't need to
be turned due to flat spots or taper wear, which the book assures us
happened often).

 Nowadays we simply wipe everything out with a paper towel, pop in new
bearing shells, mike the crank to make sure it's round, and use a piece
of Plastigage to make sure the bearing manufacturer didn't have a QC
problem.  Voila!

 Ah, the good old days...
                                                                                

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Posted by: emory!chaos.lrk.ar.us!dave.williams (Dave Williams)
Newsgroups: alt.hotrod,wiz.hotrod