Radial Piston Identification

Yes I wasn’t sure about the black area, it looked to be a very square shape so I didn’t buff it off in case it was a factory graphite coating.

Yes I wasn’t sure about the black area, it looked to be a very square shape so I didn’t buff it off in case it was a factory graphite coating.

Ah! The lesser-spotted variety! 😉

The ‘black’ areas on the thrust faces are low-friction coatings? That (to me) should indicate a ‘later’ variant but it seems there is a huge variation in design detail among US radial engines and as many differences on one engine designation as there are similarities!

I’ll have to dig my similar ‘R-3350’ piston out of its hiding place!

Ah! The lesser-spotted variety! 😉

The ‘black’ areas on the thrust faces are low-friction coatings? That (to me) should indicate a ‘later’ variant but it seems there is a huge variation in design detail among US radial engines and as many differences on one engine designation as there are similarities!

I’ll have to dig my similar ‘R-3350’ piston out of its hiding place!

see position of oil holes if you are an oilhole counter :rolleyes:

see position of oil holes if you are an oilhole counter :rolleyes:

Looks a lot better now I have cleaned it up anyway…

Post a piccy then! 🙂

Looks a lot better now I have cleaned it up anyway…

Post a piccy then! 🙂

Looks just like the 3350 piston that’s sat on my mantle..

Looks just like the 3350 piston that’s sat on my mantle..

It’s pretty much like this one
http://www.enginehistory.org/Wright/Kuhns/CurtissWrightTC18/cylinderholddowncapscrews.html

except that the oil holes on the 3rd and 4th ring are the other way round and mine only has two oil holes in the skirt under the gudgeon pin.

It has 513641 and 2 stamped on the crown, maybe 513641 is the engine number and cylinder no.2 – or would it be the piston serial number?

Looks a lot better now I have cleaned it up anyway 🙂

It’s pretty much like this one
http://www.enginehistory.org/Wright/Kuhns/CurtissWrightTC18/cylinderholddowncapscrews.html

except that the oil holes on the 3rd and 4th ring are the other way round and mine only has two oil holes in the skirt under the gudgeon pin.

It has 513641 and 2 stamped on the crown, maybe 513641 is the engine number and cylinder no.2 – or would it be the piston serial number?

Looks a lot better now I have cleaned it up anyway 🙂

I don’t believe it’s from an 1820-97 as there is a ring set less on this piston.
Strangely enough, I am not able to see an oil control ring of the type in the way i’d expect it to have.
That said it does have Wright style about it.

I don’t believe it’s from an 1820-97 as there is a ring set less on this piston.
Strangely enough, I am not able to see an oil control ring of the type in the way i’d expect it to have.
That said it does have Wright style about it.

thanks!
I like the way the gudgeon pin is held in just by the aluminium wear button. Looks like it might be TC18 and 146209 could be the Wright part number.
😎

thanks!
I like the way the gudgeon pin is held in just by the aluminium wear button. Looks like it might be TC18 and 146209 could be the Wright part number.
😎

It is a piston from a later variant of a Wright R-1820 or R-3350.

It is a piston from a later variant of a Wright R-1820 or R-3350.