RZ/RD 350 & Misc. 2-Stroke Tech BBS

Did some basic porting on my 1UA cylinder and thought I'd share the before and after photos.
It supprised me to see how the flow of the upper half off of the reeds seem to collide into a wall of metal for in the stock setup.

I don't know what effect it will have as pretty much all else except the exhaust are still stock.
Plan to use carbon reeds from Boyesen or similar though.
Next I will bore the cylinders to 64,25 with fresh pistons and set the squish.
Cheers

It is one thing to “clean up” ports and another to change the height or width of the port where it meets the cylinder. That would cause a change in port timing and vaccum for either better and sometime worse.

Matching the cylinders to the crank case is a easy blue print job that should improve transfer, because from the factory they are crude!

Yes I agree.
No messing about with port heights or widths in this case. That I would leave to professionals.
The cylinder base-to-crank port match wasn't to bad from stock from what I could see by comparing to a gasket. But I am doing top end only for now.

Anyway, are there such things as tuning port maps available anywhere??

I mean if I had the "recipe" for stage 1 or 2 port job I would consider it for a off season project.
-I have searched the net for maps, but could only find stock port maps.

Kjell

There is a port map on here from Slinger. Apparently it's good for 75whp.

I have ported my cylinders to match what he said, still awaiting firing the motor up to confirm. However, no one has said anything otherwise.

It is some aggressive porting though. Took me quite a while to get the job done, and I have the right tools!

If you're interested in tuning, I could offer my tuning manual.
Infos and samples can be found @ rd350.gmxhome.de