What should I do when my engine loses compression?

[jlobbia]

Hey guys, this is a question I have had for a while.
What things do you replace when rebuilding an engine that has no more compression? I have a XTM 457 .28 engine that has about two gallons run though and I am running it daily because of extra time during quarantine. (This week I ran almost seven tanks!) So it might need a rebuild sooner or later.
Thanks in advance.

 

[johnnydmd]

Piston, sleeve, connecting rod.

 

[tntpoof]

how about a new sleeve pinch

 

[jlobbia]

Yes I have heard or that before, could you explain what is is?

how about a new sleeve pinch

 

[olds97_lss]

A thread from when I had some sleeves re-pinched:
https://www.rctalk.com/forum/threads/had-a-few-sleeves-serviced-by-rayaracing-photo-intensive.56420/

The sleeve tapers from top to bottom. As the piston moves up, it gets squeezed by the sleeve, which is what makes your compression. When it heats up, it expands a bit and allows the piston to mass more easily. As the piston wears, the fitment when hot isn't as tight and allows compression to blow by which causes flame outs for no reason, hard starting, etc.

Most engines can easily get 5+ gallons through them before there's noticeable performance lost. Even my old cheap OS 21RG's would last 9-10 gallons.

 

[Rolex]

Most engines can easily get 5+ gallons through them before there's noticeable performance lost. Even my old cheap OS 21RG's would last 9-10 gallons.

Agree. 7 gallons used to be the good average lifetime without any issues.