rings and piston orientation for Firestone 1957 3.6hp Motor

[seahuntboater]

Greetings. After weeks of soaking and heating and prodding with blocks of wood The piston is finally free from the cylinder(piston and bore are looking nice. The rings were frozen and split but are now out. I have never done rings before so I see there is a beveled edge on each ring .

Does beveled edge orientation make a difference on re-installation?

Can I go to Napa with the old ones and the piston to get 2 rings? What material? Or can I order them someplace using measurements?

One other question? I forgot to note the exhaust side of the piston in the cylinder and it has holes on each side. The top of the cylinder has an angled top . Does that go on exhaust side?

Engine info: Firestone 3.6hp Code is 133-7-1075 stock number 10-A-111 serial 10751146

[frankr]

Beveled edge goes up (toward spark plug)
Piston has a sharp slope and a flatter slope. Sharp slope goes toward intake ports.

[frankr]

Piston ring is part number 463-1877, and date way back to 1946. Gotta be some out there someplace. Post a classified want ad here.

[seahuntboater]

Frank can you please do me a favor and double check the ring part number? I may have found a member with a NOS set. Otherwise I am trying to use my bore measurement.
Bore measurement is 2.11 inches which is more like 2 1/8 and I think you may have said spec is 2 1/16. Maybe it was honed in the past? Threre are locating pins on piston.
Existing rings are beveled with face width of .12 inches and radial wall of .09

Model info again is.
Firestone 3.6hp Code is 133-7-1075 stock number 10-A-111 serial 10751146.

I don’t want to buy rings only to find they are wrong.

If you have any other advice on buying rings based on dimensions let me know please.

[frankr]

Hoo boy, some interesting questions.

My book says 2-1/8″ bore. I don’t know if that is meant to be exact or nominal. 2.11″ does sound strange.

The bevel on the rings—that bevel is on the inner diameter, right?

I don’t have the 1957 parts book but 1958 book says part number is 463-1877, and dates unchanged way back to 1946, so I doubt the 1957 would be any different.

Oops, wrong picture

• This reply was modified 3 years, 11 months ago by frankr.
• This reply was modified 3 years, 11 months ago by frankr.
• This reply was modified 3 years, 11 months ago by frankr.
• This reply was modified 3 years, 11 months ago by frankr.

[seahuntboater]

I will assume the book part number is good.

Yes the bevel is inside diameter.

1/8 = .125 minus .110 (from caliper) =.015 smaller so maybe it was bored a bit. I have emailed otto’s with this and he says things are not matching well measurement wise. Could be my caliper. I just got a steel rule and will try that next.

[Mumbles]

Here’s a piston with rings.

https://www.ebay.com/itm/1960-Scott-Atwater-3-6-HP-Outboard-Piston-w-Rod/124125956108?hash=item1ce67bc80c:g:If4AAOSwdWZedqg-

[seahuntboater]

Looks like my numbers are a little different. Last digit is off in each case.
Connecting rod is 3735-1853 and piston is 463-1876

[seahuntboater]

just emailed the ebay seller. fingers crossed. thanks mumbles.

[Author]

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