piston question

[NEONNIGHT34609]

i have a piston that does not have the ring stops in it. by ring stops i mean the little round metal pieces that put the rings in the right location, is this a major problem? could the rings really move? i know car engines dont have these and rings dont move. just wondering if i can use it still or not.

 

[sicivicdude]

Huge problem.

4 stroke engine sleeves are single solid steel cylinders with nothing for a ring to catch on.

2 stroke pistons have stops because there are ports cut into the sleeve for the rings to catch on if they are allowed to rotate.

Do not run a piston without ring stops.

 

[NEONNIGHT34609]

makes sense thats why i asked but i dont remember stops being on smaller 2 cycles like weed wackers and such motors ? but maybe i never looked

 

[sicivicdude]

Some small two stroke engines use ABC construction so they don't use rings like the ones on the blaster.

The blaster uses true gas seal rings with a clearanced piston to allow for the expansion. Alomst none of the force of the explosion is transferred to the piston skirt, it's all centered on the top of the piston and the two rings.

ABC engines can be ringed but a lot of the gas force is transferred to the piston skirt instead of the rings.

 

[liljatownboy]

what piston make is it

 

[NEONNIGHT34609]

i will check the make tomorrow it was new in a box of parts i got but when i looked it for sure didnt have the stops in it. do some piston makes not use them ?

 

[liljatownboy]

i havent seen one for a blaster yet. is it a two stroke piston?

 

[Blaner]

i just had a wiseco with rotated rings, even with the pins! it does happen dont use it without the pin!

 

[NEONNIGHT34609]

upon looking closer the stops dont come to the end of the piston there recessed into the ring grove.about half way

 

[scotj77]

that's normal 151515

 

[NEONNIGHT34609]

ok good news my other piston the ring stops come to the end

 

[sicivicdude]

That's ok as long as the rings are made for that.

If you imagine looking into a port from the side of the motor, your rings should look solid when you push them together. If you look at the ring from the top (down into the cylinder) it should have a small "U" shaped indention on the inside of the ring.

The other style of rings has a pin that sits in the bottom half of the ring groove and the ring looks solid if you are looking at the top of the ring but is "U" shaped if you are look at the ring from the side.

You just have to make sure you have the corresponding ring set to match the piston and you should be good to go.