Encoder

[Mike Rigby-Jones]

On Wed, 13 Mar 1996 23:52:04 GMT, you wrote:


>
>    1:) Turbocharger : I have already designed most the system, but for my 
>application efficiency not power is important.
>    2:) Replace the crackshaft with a high efficiency crack. (I have one changed
>the horse power from 3.5 to 3.9!!!) These are cool things smaller with larger 
>counterwieghts. They provide a smother ride too!
>    3:) Fuel injection. Especially with a turbocharger could get a briggs in the
>stratosphere as far as RPM goes.
>    4:) A new piston : You'd melt a standard piston real quick, they're a low 
>grade aluminum, cheap as hell. Replacing it with a Stainless steel piston would 
>make it nearly flame proof.
>    5:) A new connecting rod. Most are made of aluminum to, and would shear with
>no problem at that speed and Horse power.
>    6:) Increased compression ratio. A briggs and startton has a compression 
>ratio of 4.7:1 max at the factory. I like 10:1 or 11:1 much better.
>    7:) Change Cam profile to a design more conducive to fuel injection.
>(A lot of these changes I've considered to do with my Super Mileage Vehicle)
>        Walla: A Briggs that runs at Å10HP, and 7-8000 RPM. All from a 3.5HP I'm
>deranged, it's sick that I know so much about such a shitty old engine!
>
>                                   Jim Staff
>
Hey its good to know that some sad people still play with these
things.  I had several of these engines to play with some years back.
I ported one and put larger valves in and raised the compression as
much as possible, also got rid of the so called 'carb' and put on one
from a Honda 125 OHC.  Don't know what sort of power it got but the
kart it was in went pretty well!!!

I think you would have a major problem getting 10:1 compression from
the beast.  The area needed for the valves o move up and down pretty
much limits the max compression especially if you put big valves in.

Stainless steel piston????  Bit heavy I would have thought?  Why not
graft in a crank and piston from said Honda?? ( BTW most pistons tend
to be flame proof!!!!)  This would solve the con rod problem as well
(I have seen several of these snap even when the engine was powering a
mower)

The flywheel is also a little suspect for high rpms.  In fact its
lethal so get rid of it or at least strengthen it in some way.

As for a turbo, well it'd have to be VERY small just to be turned over
by a B&S let alone produce boost.  I managed to get some kind of
vacuum pump from a old milking machine which could be used in reverse
as a pressure pump.  It was a vane device and had a fair displacement
so I was toying with the idea of supercharging but never really got it
finished.  I think that would be the way to go instead of turbos.

cheers

Mike RJ