Pioneer adventures
First, thanks to Pioneerguy and P62 for advice and encouragement back in July. As I was whining back then, I wanted to make a P-52 because the ignition had died in my old P-51. If that hadn't happened, I wouldn't have found AS (and wouldn't have heard of such a thing as a 655BP for that matter). One thing led to another, and I got pretty geeked up. After finishing some other projects, incl. having the engine out of and back into a car, I got started on the saw.
Where the P-52 is at now:
- I made a pop-up piston in order run w/o a jug gasket and gain a little compression. It turned out pretty enough, and it's squishing at about .020".
- Port matching and some case matching
- Cleaned up lower transfers and sharpened dividers
- Whittled off the little shoulders in the old-type upper transfers (Isn't that what they're for - to grind off?)
- Eliminated exhaust port bridge and raised the port a bit. May go another mm or so to where I had the old P-51, but I wanted to try it this way first since I can't put the metal back into the port.
- Doctored the carb - did this years ago, actually
I've run it a little, and it seems to be building compression and is beginning to run like the old P-51.
Part Two
I was initially ashamed of myself for coming down with the affliction that I believe is CAD, but now I'm really embarrassed. I saw a 655BP on flea-bay and figured I needed it. It was advertised as a strong-running saw, but it showed up very weirdly maintained. More funky little things than on any saw I've worked on, though they wouldn't cost anything to fix.
But here's the bad part: The cylinder and piston were scored beyond my ability to clean them up, and I didn't dare to just put new rings in it. I know, I should have sent the saw back.
Anyway, here is what I have planned to transform the 655 from a great lumbering beast into a real runner:
- Port matching/ case matching (very little needed)
- Modify muffler (done)
- Add a velocity stack from my good ol' days
- Other geeky little mods, including changing the carb into a toilet
- Clean up lower transfers and sharpen dividers - I don't want to do much there, because I think it has the effect of increasing crank case volume. On the other hand, it seemed to help my P-42 and the P-52.
- The upper transfers and boost port are just so dang purty that I'm reluctant to monkey with them. And it's still an unfamiliar saw to me. I haven't done much porting anyway, and what I did before now was almost thirty years ago.
- Had been thinking to run it w/o jug gasket. The original jug squishes at .024 without gasket. I'd raise the exhaust port correspondingly.
The shiny new jug and piston arrived today from Rottman's. The cylinder is slightly different in that there is no skirt. It matches the case very nicely, and the included gasket is about .011" - likely less once it's squoze down. Maybe I should just shine up the exhaust port and put it together with the gasket. Longevity is going to be a priority, since I have so much money tied up in it and parts being scarce.
I do have dimensions and port timing numbers, if it matters. Any thoughts on what I'm doing, could do, or should do on either of these old work saws would be much appreciated.
Thanks,
Hillwilliam
