Piston Rings

[portedmetal]

I have a flat top piston (arcracing.com item number DJ-2295). I recently blew the rings and now burning oil and fouling plugs like crazy. I wanna know if this piston uses T2 rings or T3 rings. I also wanna know some of the main causes of piston ring failure. Thanx.

The rings I blew were these DJ-2290, at arcracing.

 

[slideways]

How do you think you "blew" them? Without a major engine failure a ring usually won't blow or crack. Typically detonation would cause a piston to break before the rings. Did you have to reinstall the old ones with the new piston? The rings go in a certain way and if you ran the engine for a long time you should have honed the cylinder first also. I wouldn't reuse rings with a different piston.

 

[r_chez_08]

T3 = 0.96mm rings, T2 = 1.45mm rings.
I think you have tier 2 rings and piston, but I am not 100% sure.
I do not know the cause.

 

[portedmetal]

I installed the new rings with the new piston. The engine was ran for maybe a couple of hours out the box before I changed parts. once I put a new spatk plug in the motor runs awsome for about 10 minutes, then it starts smoking and finally dies. I change the plug and its good to go for another 10 minutes. Maybe I'm running too much fuel but the smoke is white with a little blue in it.

 

[Bluethunder3320]

were the rings a tight fit to the piston or loose?

 

[portedmetal]

Once they were on I could rotate them inside.the grooves. I don't remember if they could move u and down.

 

[slideways]

That's normal.. what you need to look for is the gap when the ring is on the piston and you are inside the bore. Like i said i remember that alot of rings have to be installed correctly right side up. I'm not sure if these are like that or not.

 

[Bluethunder3320]

on all the engines ive seen, sometimes the middle ring has a groove underneath it. the surface area of that one is less than the top.

if you put one of the rings inside the bore the gap should be minimal. if you use a piston/rings that is too small for the bore than obviously there will be much less compression but you can get the same symptoms as worn piston/rings

 

[portedmetal]

Would too much oil in the crankcasr cause this?

 

[devino246]

Did you stagger the gaps on the rings when you installed them?

 

[Doc Sprocket]

Would too much oil in the crankcasr cause this?

It could.

 

[portedmetal]

Yea I staggered them. None of the gaps are on top of each other and none of the gaps are over the wrist pin.

 

[Russ2251]

Rings spin in grooves anyway so this would not be an issue.

 

[sexyvicta]

what does the bore look like now? maybe glazed from running too rich?

did you measure the ring gap?