identify this strange porting layout

[masterblaster]

This is a strange layout for a yami motor its a 5 mill stroker cylin,the boost port is extended all the way down,like maybe a piston was used with a hole in the side to cool the crown at one time?its got a reg round top yami piston now.

The transfers are really long and pointed on the exh side,the matching porting on the case is laid back all the way into the epoxy,it looks to create a pocket? what does this achieve? I have ridden this motor,it has low duration #s and rips pretty hard.going to run it with a new crank and thought I might ask some others in the know around here before I put it back together.

 

[chriselmore_1]

wow thats some serious porting! hiw does it run?

 

[SUPERTUNE]

What are you doing with P.C.'s engine?
Back in the day when Don Able came out with this design it was way ahead of it's time!
We used these in the pro and expert 785 mod sport class boats (WaveBlasters).
The slotted boost port was to make the boost port bigger by removing the cylinder wall and let the piston be the wall.
We also cut windows (holes) in the pistons to burp out the heat underside of the piston crown.
As you all know we didn't have very good ignition systems back then and burned up a lot of pistons!
Seadoo 800 engine has some of this boost port technology.
Not really needed for where we are now for Freestyle/Freeride powerbands.

 

[masterblaster]

he rides in our group,we traded some stuff out. It might be old school cool but its better than my ported 62t cylin I have on my other 5mm stroker crank now.He said you told him the cases were bad or worn out or something so I was going to port my own.whats wrong with them?other than the crap intake ramps,lol I could smooth those out.
What are the long transfer shapes for,Ive seen epoxy ramps put in the bottom of cylin and ive seen cases ported laid back like this,whats best? why where they made like to start with ,seems strange.