RCU Forums - How do you break in an engine??

RCU Forums (https://www.rcuniverse.com/forum/)

- Beginners (https://www.rcuniverse.com/forum/beginners-85/)

- - How do you break in an engine?? (https://www.rcuniverse.com/forum/beginners-85/906527-how-do-you-break-engine.html)

How do you break in an engine??

Topic says it all. Do you need any special fuel?? Or anything other than that?? The engine is a Magnum .28 if that matters at all.

How do you break in an engine??

Quote:

Originally posted by crash guy
close the needle valve until you can hear the most rpms, then open it up until its rich and smokey. run 2 or three tanks through it.

That advice would work for ringed engines. It's about the worst thing you can do to an ABC engine and I'm pretty sure the Magnum is ABC. They need to get up to temperature fast. Running them rich and therefore very cold can ruin the cylinder bores.

The type of engine matters a lot though the precise make doesn't.

Steve

How do you break in an engine??

Steve Lewin has given you the straight poop on breaking in any ABC or ABN engine, Never make blubbery rich initial runs. Most bronze sleeves are machined with a choked taper bore and this sleeve expands more than the aluminum piston with heat therefore to acheve the proper piston/sleeve seal at operating temperature the cold fit at the top of the bore is squeaky tight and at running temp you will have the right clearance. If you break in rich therefore cold there will not be enough clearance and the sleeve will be damaged and never able to perform as intended.

By the way the Magnum .28's are true ABC and are excellent little engines with great carbs that gives the engine a very respnsive throttle when tweaked right. There are four of them on the airplane in my avitar.

John :)