RE BS ENGINES

[ducharme at eiss1.psf.ge.com]

Ed Lansinger wrote:

> I have heard of people having lots of success with aluminum pistons and heads > that use a 
> (ceramic) thermal barrier coating.  Maybe this would be a good solution to the>  original 
> question (which I missed).

I like it - ceramic pistons/cylinders for B&S engines...

>From what I have seen, the limiting factor on the B&S as far as HP production
is concerned is the basic design (L-head, small valves, limited heat rejection
capacity from the fin area, no pressure lubrication to cool the piston crown).

You can put bigger valves in, enlarge the ports, regrind the cam lobes, and
add a larger carburetor(throttle body) but the head design impedes bumping up 
the compression ratio from its lowly value, and without improved cooling, the 
engine will self-destruct from seizing if the crank or connecting rod doesn't 
break first.  But I still think the're a great engine.  

My project engine was purchased in 1970 when I graduated from high school, cut 
acres of grass for many years until the mower deck rusted away, was lucky if it
saw an annual oil change, and when I dissassembled it last fall before starting
my senior project, I couldn't find a ridge at the top of the cylinder!  The 
aluminum bore still had crosshatch marks in places and, other than exterior 
rust, corrosion and flaked paint, showed little signs of such abuse.  For its
intended purpose, that's hard to argue with.

What was the original question?

P.S. Ed - Great article in Circuit Cellar Ink.  It helped me greatly.

Cliff Ducharme