Best Porting Instructions?

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fields_mj

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I have a couple of older saws that I'd like to port. Figured I would pick up a new aftermarket jug and piston so I don't trash the OEM since the OEM currently works fine. I've been interested in doing this for several years now, but never had a saw that I could afford to have down for a while. I'm an engineer by trade, but spent several years working as a carpenter doing residential construction, and then spent a few more years working as a machinist. I enjoy working with my hands, and I think this is well within my skill level and would be a fun project. I've watched several videos on porting, and most seem to focus on figuring out and changing the timing. I'm not really interested in going that far. I'd just like to rework the ports so the saw breaths a little better. At one point, many many years ago, there was a good thread on here about doing exactly this kind of thing, complete with pictures. After searching for a few hours, I can't seem to find it. My main question is on laying everything out. How do I figure out where the edges of the ports should be? If anyone has a link to that old thread, or to a thread or video that deals with this, I'd really appreciate being directed towards it.

Thanks,
Mark
 
I bought one of these on Ali recently, unlimited rpm adjustment, some of the newer models have pedal throttle mine have pedal on/off.
I bought two elbow pieces because they are accurate but I suspect not super solid. Suitable for smaller grinding/milling and polishing work.
Example: https://www.aliexpress.com/item/1005001989168602.html?spm=a2g0o.productlist.0.0.30adc701Bsnmh1&algo_pvid=b32c8236-d59a-4673-92fa-5b5f3ba3803a&algo_exp_id=b32c8236-d59a-4673-92fa-5b5f3ba3803a-25&pdp_ext_f={"sku_id":"12000024685789147"}&pdp_pi=-1;896.89;-1;216.5@salePrice;NOK;search-mainSearch
marathon.png
 
I bought one of these on Ali recently, unlimited rpm adjustment, some of the newer models have pedal throttle mine have pedal on/off.
I bought two elbow pieces because they are accurate but I suspect not super solid. Suitable for smaller grinding/milling and polishing work.
Example: https://www.aliexpress.com/item/1005001989168602.html?spm=a2g0o.productlist.0.0.30adc701Bsnmh1&algo_pvid=b32c8236-d59a-4673-92fa-5b5f3ba3803a&algo_exp_id=b32c8236-d59a-4673-92fa-5b5f3ba3803a-25&pdp_ext_f={"sku_id":"12000024685789147"}&pdp_pi=-1;896.89;-1;216.5@salePrice;NOK;search-mainSearch
View attachment 973333
My dentist has the same rig
 
I bought one of these on Ali recently, unlimited rpm adjustment, some of the newer models have pedal throttle mine have pedal on/off.
I bought two elbow pieces because they are accurate but I suspect not super solid. Suitable for smaller grinding/milling and polishing work.
Example: https://www.aliexpress.com/item/1005001989168602.html?spm=a2g0o.productlist.0.0.30adc701Bsnmh1&algo_pvid=b32c8236-d59a-4673-92fa-5b5f3ba3803a&algo_exp_id=b32c8236-d59a-4673-92fa-5b5f3ba3803a-25&pdp_ext_f={"sku_id":"12000024685789147"}&pdp_pi=-1;896.89;-1;216.5@salePrice;NOK;search-mainSearch
View attachment 973333
If I were going to make a job if it, this would be a really nice setup to use. I have a couple of dremel tools. Since I'm at the Novice level, my plan is get the appropriate cutters and use the tools that I already have.
 
Finally found Brad Snelling's thread I was looking for. I wasn't going back far enough. It was from 2009. I didn't go back far enough in my searches.

The 361BB porting thread that I was looking for.
https://www.arboristsite.com/threads/porting-the-361-big-bore.85488/
Another thread with lots of pics from about the same time.
https://www.arboristsite.com/threads/porting-101.108900/#post-1715133
Another thread where some questions are asked and answered.
https://www.arboristsite.com/threads/cylinder-porting-for-dummies.85802/
Review of the 361BB prototype just so I can find it later
https://www.arboristsite.com/threads/ms361-big-bore-kit-review.82379/page-2
 
Finally found Brad Snelling's thread I was looking for. I wasn't going back far enough. It was from 2009. I didn't go back far enough in my searches.

The 361BB porting thread that I was looking for.
https://www.arboristsite.com/threads/porting-the-361-big-bore.85488/
Another thread with lots of pics from about the same time.
https://www.arboristsite.com/threads/porting-101.108900/#post-1715133
Another thread where some questions are asked and answered.
https://www.arboristsite.com/threads/cylinder-porting-for-dummies.85802/
Review of the 361BB prototype just so I can find it later
https://www.arboristsite.com/threads/ms361-big-bore-kit-review.82379/page-2
Thanks, just what the doctor ordered. Lots of good reading, time to open my Office Writer at page one and start making notes :picture:
 
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