Piston friction

[ttuzun]

Its my second post today but they were separate subjects.

When trying to take apart the engine. I also realized the piston kind of gets stuck at the apart part. There is a lot of friction and i need to apply it a good amount of force to release it, however its really smooth and friction free on the bottom.

Is this a normal situation or does it show some problems in the piston and/or the sleeve

(as i explained in my other thread that the sleeve is stuck too. So i am thinking this has something to do with that.)

Thank you

 

[Crash]

The sleeve has a taper

the pinch is tight at top of sleeve

 

[ttuzun]

oh. good to know thanks

Should it be certainly replaced? or would it cause just performance problems?

 

[johnnypoopoopants]

The piston and sleeve are SUPPOSED to be tight at the top of the stroke. You are not supposed to be able to pull the piston through the top of the sleeve. If you can pull the piston through the top of the sleeve fairly easily then it is definitely time for a new piston/sleeve. What you are describing is normal, in fact its good to have pinch at the top. After engines are ran, sometimes it is hard to remove the sleeve. I put zip, ties through the exhaust port and turn the engine over, That usually helps push the sleeve out. The symptoms you are describing are perfectly normal, and you would not have any performance problems from this.

 

[Shaun]

yes thats totally normal for a engine to have alot of pinch at the top!! I'm in the process of breaking in a sh m28 p3 engine in my savage x and i cant even turn it over without loosening the glow plug "its that tight and has that much compression" so no worries.......

 

[Larsenracing]

In essence the pinch at the top of the sleeve is your Rings link your 1:1 car. It creates the seal to keep compression creating the Power from the explosion of the air/fuel mixture.

 

[ttuzun]

good to now. I am slowly learning. I don't need to spend some good old cash on a new sleeve.

Thanks a lot everyone!