Fantastic. I bought a stock 49cc engine today im going to strip this one and blueprint , port it. My cylinder has a 1 boost port but no window on that side of the piston.
So for my application a few more ports would be better?
What cutter do you use to cut these boost ports in the cylinder?
I will be using my Bridgeport. Also what is the best cutter to cut the window in the piston I was just going to use my Endmills for Aluminum?
How High in the piston do I cut the window?
And if I add 2 more boost ports in the cylinder do I cut 2 more ports in the piston or just cut a long horizontal window in the piston to match it ?
Do you use better crank bearings and crank seals?
Thanks again Mike
I use a carbide barrelcutter on a Dremel and drill my holes in the piston by hand in my hand with a glove literally holding it..……….I chamfer and debur with a deburring tool aswell as 2000/4000 grit sandpaper and jewelers files.
I do all my work with a hacksaw,dremel,handfiles and sandpaper also 18v cordless impact gun and drill in my hobbyroom on the benchtop as it helps keep down costs over time as cylinders and pistons are very expendable and the more theyre modified the lesser they last...
The amount and type of 2 stroke oil used dictates that too..
A bone stock engine has a service life of 120hours when used as a tool based engine.......When used on rideables and modified I cut that in half off the bat and its usually pretty accurate..
So depending on how you modify the cylinder each and every subsequent cylinder after that will also need to be equally modified aswell...…
For my pocketbikes I had a whole slew of extra engines already built sitting on the shelf all built ready to rock n roll as anything can happen and ruin these small engines fast..
When you start getting over 200psi the heat generated from using gas no matter even if its VP the engine will run hot unless tuned fat and tuning 2 strokers fat doesn't make power and screaming revs....
Tuning a 2 stroke on the edge of being too lean does and that generates a lot of heat like I said and when that happens those open transferport cylinders expand hugely and compression starts to drop off staving off power...
When that happens its time to tune the engine to run on alky/methanol mix or stick a basegasket under it to get it in the .038"-.040" range so youre able to run the VP and tune to temps....
A stock engine is built with .062-.065" of squish stock with a compression ratio of roughly 8:1...…...Anything under .050" is gravy...…..