Three Ring Pistons vs. Four Ring

[amodel25]

I am in the process of freshening up a .030" over 254 cu.in. flathead six truck motor for my '49 coupe. I bought a set of rings off E*AY for four ring pistons. When I tore into the engine it has three ring pistons. Can I use the top three four ring rings? or do I need to keep looking for a set of three ring rings. The engine appears to be relatively low miles and I was not planning on boring it or replacing the pistons.

 

[19Fordy]

This is worth reading.
http://fordbarn.com/forum/showthread.php?t=109097&highlight=ring+pistons

 

[Ronnie]

Depends on what the ring configuration is as to widths on the piston and what you bought as well.What are the widths of both.How many oil rings in the set you bought,what is the part number of the set.

R

 

[amodel25]

The rings are:

Continental Steel Flex p/n 839 - .030" - .039"
Ford 6 254 Engine (48-51)

Top ring .092" thick
2nd ring .092" thick
3rd ring .185" combined thickness
4th ring .185" combined thickness

Pistons:
Top groove .098"
2nd groove .098"
3rd groove .188"

Any opinions about using the top three rings in a 3 ring piston?

 

[Ronnie]

What style are the oil rings? One piece or 3 piece?

R

 

[amodel25]

3 piece

 

[Ross F-1]

Is the 3rd (bottom) groove wide enough for an oil ring? Is it above or below the pin?

 

[amodel25]

The bottom (3rd) groove is wide enough for the oil ring, located above the pin.

 

[Ol' Ron]

I recently repaired a 276 with rusty cylinder walls with a set of Egge 3 5/16-.020' 3 ring pistons these light weight pistons have metric rings from a Volvo truck. Can't beat that. Check with them on sizes.

 

[Ronnie]

3 piece

Are both oil rings the same