Dan Best wrote:

snip

Is it possible to temporarily increase the power
outpuit of a small engine by some means, perhaps a blower, a turbo or
even using NOS?

Some of the newer diesels have a turbo charger, but my personal
philosophy is to avoid them. This is based upon the notion that added
complexity will, on average, lead to more things to go wrong. Note that
others will disagree and advocate the use of smaller, turbo equipped
engines.

It should also be noted that turbo charging an engine does not produce
more energy (fuel mileage) from a gallon of fuel, it merely allows a
smaller displacement engine to behave as though it were a larger one and
consume more of the air/fuel mixture per gulp.

I've never heard of a NOx equipped cruising sailboat. While this could
increase the power of an engine, I see two problems with it. The first
is that I've never seen a fuel dock that could resupply you with NOx.
The 2nd is dealt with below in the discussion dealing with exceeding
hull speed.

I am primarily interested in times when it is a safety
issue, not for convenience so potential engine damage might be
acceptable.
Any ideas?

Dan Best Is correct about a lot, including the bow wave (but I am a
naval architect as well as a marine engineer and thirty years an engine
professional) but I would (as he did allow) disagree about turbocharging
a diesel.

I have had owned several turbocharged diesels, and these engines had no
operating life disadvantage over the naturally aspirated version - as
the result of a casualty, I replaced an NA engine with the same family
but turbocharged - Same - Same except the lack of smoke, lag in the ramp
and it would not bog when the NA did.

NOx is simply impractical, the WOT/NOx (wide open throttle w/ Nitrous)
is very limited with any reasonable bottle size. It has been used
extensively for drag racing and open class recip (piston engine)
hydroplanes. Neither example is known for duration.

Diesels actually like turbochargers in spite of many other issues.
Diesels are all smoke limited and more air helps this and so does the
heat recovery that can be achieved. Charge air coolers used in over the
road vehicles lose some of the heat advantage in favor of peak
horsepower.

The other issue I have seen often is simple, engines are purchased on
cost as a first consideration and weight as a second. Dollars per
horsepower, a turbo engine will usually win and pounds per horsepower -
no contest.

Adding a turbocharger to an existing engine, without a manufacturer
supplied kit is not a small task - I have done this, I know. There is
not anything that can be done to increase the power output of an engine
that will succeed all around.

Matt Colie