Part #1 Stihl 038 Super to ported 038 Mag build -Part #1 (pic heavy) I tried to think out of the box since I do not have the equipment for tig and brazing. Antique window latches - one brass one cast iron - both cleaned up and shaped with a file. Gutted the muffler and dual ported. For some reason this 038S only has a single port muffler. Before: After gut and cutting openings: I did go about 1/3 larger on the recoil side. Ready for install after I match the port. (got excited and had to paint) Deflectors held in place with brass screws and nuts then peened in place from the inside.
I think this is a neat build that you are doen. Stihl 038 is a workhorse saw and one of my favorites that stihl ever made.
That should make it breathe a little better. A good muffler mod can be a really good improvement. Glad to hear you matched the port also. Not every one does that.
OK -I finally made some time to stat playing with the build again. Not doing any grinding in the squish. The piston just hits the the cylinder with no gasket so will have to use a gasket. I'll find something right at 20 thou. Here are my timing numbers E 105 T 124 I 72 I would like to go in a safe direction with the numbers and but not over kill. A well known builder did one quit a while ago and came up with these numbers 101 122 75 Should I shoot for those? Input would be greatly appreciated! Once I get some ideas from you guys and get it finished I'll do part 3 with pics.
I say go for it. You will loose a little bit of compression but with a squish of around .020" that should make up for it. You will gain some blow down and point the top of those transfers toward the intake side. You should also gain some RPM's. I take it you are raising those ports.
Had to sleep on it.... My post above - Sorry I was thinking 2 things at the same time. The numbers are with gasket cranked down and squish at 20. I may tighten up the squish band old school with some sand paper and a wooden dowel and rotating the cylinder not the dowel. There is a raised squish band in the cylinder about 15- 20 thou so can stay away from the wall. If I smooth out that part of the casting and thin the gasket might be able to capture more compression as long as the firing stays on that area and don't go too deep. There room ro work with knowing the piston hit with no gasket. Will recheck all numbers after. The brandy new tungsten carbide burrs are hungry for some aluminum!
