John Lupien writes >
> > The Hirth roller bearing crank is another way to achieve high BMEP
> > and RPM levels, but at a very high cost.
>
> Yet another method, used for very high RPM and specific output, is
> the crank-pumped, premix or oil-injected two-stroke mechanism, which
> it might be argued is also a low-pressure or no-pressure oiling system.
> The highly mobile gasoline serves to wash the oil into the crevices and
> journals quite effectively, with the disadvantage of having to deal with
> oil smoke emissions somehow (like, uh, venting it to the atmosphere...).
I used to ice race a SAAB 96 with a two-stroke. Two of them, actually. I
got a 1963 850GT after pounding the 1961 850 into a large lump of wrinkled
steel. (LBC content: It was getting hit by a Mini that started the chain
of events leading to multiple flips.)
Anyway, the crank ran on double ball bearings. Do all two-strokes have
ball/roller bearing cranks?
The 4-stroke Honda 600 roadster had roller bearings on crank and cams.
Had a factory redline of 10,000 RPM. BMC was afraid of it until they
found out that it did not handle as well as a Spridget. Anyway, I asked
a seller why it had no oil-pressure gauge. He said, "What does it need an
oil-pressure gauge for? It has no oil pressure."
Phil Ethier, THE RIGHT LINE, 672 Orleans St, Saint Paul, MN 55107-2676
h (612) 224-3105 w (612) 266-6244 phile@stpaul.gov
"Some of them own little sports cars" -Jethro Tull
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