Terry Syd
Addicted to ArboristSite
Squish
The squish on my saw is 41 thousands at the edge of the piston.
If I was setting up a racer I would plasma coat the top of the piston to bring the squish down to 20 thousands. This would also reduce both the exhaust and transfer timing a few degrees. Since the transfer timing is already a bit long, this would help the blowdown problem. I could raise the exhaust port back up to stock timing and have the blowdown I want.
I could also have more material sprayed in center of the piston to create a dome and bump the compression ratio.
The transfer ports are very easy to make larger. If you take a look at the picture of the transfer tunnel cover, you will see that the insert into the transfer port can be trimmed back another 1.5mm. In other words, you can widen the transfer port another 1.5mm to get back the flow you lost when you dropped the transfer timing.
The Time/Area of the existing transfer port is enough and perhaps just a tad too large for the RPM that the saw is presently cutting. So, it may not be necessary to widen the transfer port, however, a racer may wish to raise the exhaust port some more and the extra transfer area may be necessary. In fact, a second set of transfer ports can be cut into the jug wall from the existing tunnel. All it would take would be a drill and some needle files to do the work. The potential transfer area is there, it just needs the tunnels enlarged to feed them.
All in all, I am very happy with the way the saw performs. It took a bit of work to figure out how to mod the new Husky strato, but anybody who says these stratos can't be modded to perform as well as the conventional two-stroke just hasn't played around with them yet.
If I was racing a Husky strato, that strato port would get a second carburetor. Perhaps in the future we will see someone step up to the log with a tricked out Husky strato so we can see what some serious mods would do.
The squish on my saw is 41 thousands at the edge of the piston.
If I was setting up a racer I would plasma coat the top of the piston to bring the squish down to 20 thousands. This would also reduce both the exhaust and transfer timing a few degrees. Since the transfer timing is already a bit long, this would help the blowdown problem. I could raise the exhaust port back up to stock timing and have the blowdown I want.
I could also have more material sprayed in center of the piston to create a dome and bump the compression ratio.
The transfer ports are very easy to make larger. If you take a look at the picture of the transfer tunnel cover, you will see that the insert into the transfer port can be trimmed back another 1.5mm. In other words, you can widen the transfer port another 1.5mm to get back the flow you lost when you dropped the transfer timing.
The Time/Area of the existing transfer port is enough and perhaps just a tad too large for the RPM that the saw is presently cutting. So, it may not be necessary to widen the transfer port, however, a racer may wish to raise the exhaust port some more and the extra transfer area may be necessary. In fact, a second set of transfer ports can be cut into the jug wall from the existing tunnel. All it would take would be a drill and some needle files to do the work. The potential transfer area is there, it just needs the tunnels enlarged to feed them.
All in all, I am very happy with the way the saw performs. It took a bit of work to figure out how to mod the new Husky strato, but anybody who says these stratos can't be modded to perform as well as the conventional two-stroke just hasn't played around with them yet.
If I was racing a Husky strato, that strato port would get a second carburetor. Perhaps in the future we will see someone step up to the log with a tricked out Husky strato so we can see what some serious mods would do.