Poulan 3700 rebuild

[walcen]

Hi folks, hope you're all well.
Just a little update regarding the piston rings, I've managed to chase down an alternative that can be easily made to fit. For anyone who is interested.The Poulan uses 47.6mm x .7 rings. The HUSQVARNA 61 262 365 CHAINSAWS 48MM X 1.5 are a good match, they just require lapping down to the required thickness. I'll post some pics and explain how I do this and reset the rings to the correct 47.6mm.

 

[walcen]

Hi folks, hope you're all well.
Apologies for my slow progress but after three years dodging covid it finally caught up to me.
Any how I managed to resize a couple of piston ring for the poulan.
I used an old metal ring that I had laying around, I drilled and tapped a bunch of holes in it and fitted machine screws all around it for ring support.

I sat the ring in and adjusted the screws to match the cylinder bore and then heated the ring with a blow torch.
I then adjusted the ring gap as required using a file. I calculated the ring spring gap to be around 7mm, roughly 15% of the bore size. Using a 7mm drill bit I clipped the ring on it and heated it until it dropped off. finally I made a ring holder to sit the ring into so that I could surface it down to the required thickness. The rings fit very well and I'm pleased with the result.

Now I now some of you may be thinking, what a lot of mucking around for a couple of rings, well yeah but this being a hobby project and me being retired I can afford to take some small extended side tracks. Its all part of the journey.