Chuck,
If you liked the old Detroit Diesels I will try to find you references or
links to a few of the military 2-stroke diesels that are even cooler. One
of the Junkers bombers of the last world war was powered by an opposed
piston 2-stroke diesel. It was an in-line engine with two pistons per
cylinder and a pair of crankshafts, one in the normal location and one on
top with a train of spur gears connecting them. Unlike the DD product it
had no cams or poppet valves, but intake ports uncovered by the pistons at
the bottom of the sleeve and exhaust ports at the top of the sleeve. That
engine held the record for specific power from a diesel for decades and is
the only diesel to power an aircraft to my knowledge.
The last of our pre-nuke subs used 2-stroke diesels that also had two
pistons per cylinder but only a single crank. The cylinders were horizontal
with the crank below them. Each piston had a con rod to a huge rocker arm,
and another con rod from the opposite side of the rocker to the crank.
There were eccentrics in the pivots of the rocker arms that could be
adjusted to shift the stroke of each piston in the cylinder to allow for
dynamic tuning of the timing and compression ratio. For example when
operating at part throttle the pistons would be shifted towards each other
to increase the compression, holding the absolute compression constant
rather than the ratio.
Greg
----- Original Message -----
From: "Chuck Rothfuss" <crothfuss@coastalnet.com>
To: <land-speed@autox.team.net>
Sent: Thursday, February 24, 2000 7:37 PM
Subject: Re: Flathead V1 (2 cycle?)
> Rich, List,
>
> I've just been doing some catching up on my mail reading and had a
chance
> to read all the V1 stuff from start to finish in one sitting. Early on in
> the discussion of 2 cycle engines I started thinking of my favorite 2
stroke
> engines and wondered when they would be brought up. Well, they haven't
been
> so I'll do it myself. My personal opinion, as a guy who has smelled of
> diesel fuel for the majority of his adult life, is that the Detroit Diesel
> is the KING of 2 stroke engines!
>
> The design of the engine will not allow it to operate without a blower,
> so that may keep it out of some LSR classes, but it's a screamin' monster
of
> an engine for a diesel tuner. With a long enough stroke (to allow
> sufficient burn time to produce power) the design may be adaptable to
other
> fuels... but why mess with perfection.
>
> Hey, there's an interesting question for the list. Are there any
Diesel
> truck folks on the list yet?
>
> Chuck "It's all in the helix" Rothfuss
> ECTA #9, "USS Wankel"
> Pole Cat Hollow, NC
>
|