Got the urge to build a steam engine. I was looking at a few plans and seen the piston grooves are .005 and .010 wide. How do I cut a groove that thin and how deep do you make the grooves? I don't believe it says on the plans I was looking at. Thank you.
Piston Grooves
- Thread starter khand
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These are just oil grooves often used on small steam engines and serve as a piston ring. Best to grind up a tool to a 90degree "V" point and feed straight into the edge of the piston.
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Here is a photo of the piston from my current IC engine project. I use the same style of grooves for steam if I am not using an O-Ring seal.
The two grooves at the left side were made with a almost sharp vee 60 degree threading tool that I use for 00-90 threads. The depth of the grooves is 0.005 and the piston diameter is 0.375 inch. The wide groove on the right side is for distributing oil from an oil cup and would not be used on most steam engines.
Gail in NM
The two grooves at the left side were made with a almost sharp vee 60 degree threading tool that I use for 00-90 threads. The depth of the grooves is 0.005 and the piston diameter is 0.375 inch. The wide groove on the right side is for distributing oil from an oil cup and would not be used on most steam engines.
Gail in NM
I have a grooving tool made by Nikcole that has inserts .019 wide. You could buy the insert and make a holder. Then increase the ring to .017 - .018.
On the cheap - grind the end of an old hacksaw blade.
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Here is a photo of the piston from my current IC engine project. I use the same style of grooves for steam if I am not using an O-Ring seal.
The two grooves at the left side were made with a almost sharp vee 60 degree threading tool that I use for 00-90 threads. The depth of the grooves is 0.005 and the piston diameter is 0.375 inch. The wide groove on the right side is for distributing oil from an oil cup and would not be used on most steam engines.
Gail in NM
Hi Gail,
Is the resulting compression good enough for ignition/firing and power wise?
From your foto. Is piston C.I.?
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Gus,
I have used this system on over 25 engines, but only for small bore engines. That is for 1/2 inch (13mm) and under. Most of them are cast iron pistons in cast iron cylinders. That is the best material combo for my style of building. This is a cast iron piston as used in my "Tiny" series of hit-n-miss engines. Takes careful lapping and fitting but makes good running IC engines.
Gail in NM
I have used this system on over 25 engines, but only for small bore engines. That is for 1/2 inch (13mm) and under. Most of them are cast iron pistons in cast iron cylinders. That is the best material combo for my style of building. This is a cast iron piston as used in my "Tiny" series of hit-n-miss engines. Takes careful lapping and fitting but makes good running IC engines.
Gail in NM
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Barry: I don't know what an optimum value would be for width and depth. If the groove is too big it will not fill with oil to act as a seal. If it is too small it won't hold any oil. The 0.005 depth that I use works for me so I have not questioned it very much. It seems to be a popular value but I have seen both wider and narrower ones on plans. I think that it is a good starting place for small engines.
Gail in NM
Gail in NM
