R - 3350 help

[Freshmechanic]

Hi everybody, I am getting my A&P license and right now I'm in training in powerplant. I'm working on the 3350 because it is a fun challenge and it makes my team of 3 look like the alpha of the class all. So the problem is one of the cylinder piston got melted onto the cylinder barrel we can wiggle it but the cylinder just won't pull out. If my team manages to get it out we get 20 points extra on out marking period grade so can anyone help us out ?

 

[FLYBOYJ]

Hi everybody, I am getting my A&P license and right now I'm in training in powerplant. I'm working on the 3350 because it is a fun challenge and it makes my team of 3 look like the alpha of the class all. So the problem is one of the cylinder piston got melted onto the cylinder barrel we can wiggle it but the cylinder just won't pull out. If my team manages to get it out we get 20 points extra on out marking period grade so can anyone help us out ?

Where in the cylinder is the piston stuck? It's evident this jug will ever be airworthy so I would use heat (acetylene) to try to expand the cylinder barrel and would try pushing it further into the barrel to break it free or pulling it out by the connecting rod - assuming its still attached. Hope this helps. Maybe you could post some photos of this.

BTW I'm an A&P/ IA. Welcome to the club!

 

[MiTasol]

If the cylinder is a top one or (better still) the engine is prop shaft vertical you can try this.
If you are sure that the rest of the engine is free to rotate do it with the cylinder firmly attached to the crankcase.
If you suspect other cylinders are also seized you will have no option but to do it with the cylinder attaching hardware removed. WARNING - IN THIS CASE DO NOT TRY THIS UNLESS YOU CAN TOTALLY ELIMINATE AIR FROM THE CYLINDER BECAUSE WHEN THE CYLINDER COMES FREE THE EXPANSION OF THE TRAPPED GAS WILL FIRE THE CYLINDER ACROSS THE ROOM LIKE A CANNON SHELL. If the cylinder is still attached to the crankcase the prop shaft WILL rotate - possibly quite quickly
With the bottom spark plug still fitted fill the cylinder with VERY WARM heavy grease or moderately thick wax so the air will float to the top) and allow to cool.
Modify a spark plug to take a grease fitting and pump grease in - it will take a while to get down to the rings and fully seal and then should push the cylinder off.

Good to see FAA still do practical testing - something a lot of other countries could learn from

Mi Tasol
Ancient A&P and licensed Engine/Airframe AMT in four other countries - not licensed for electronic trades or ballast fitting (Radio installations).

 

[GregP]

1. Get a hi-pressure water sprayer and put a quick disconnect on the end of it. 2500+ psi.
2. get and old spark plug and break off the ceramic and use a hammer, etc. to chip it out.
3. Get on an end mill and drill and tap the spark plug for a quick disconnect.

*. Make sure the pushrods or overhead cam are out! Won;t work unless the valves are free to move, so you could also just remove the lifters.

4. Make sure the valves are in and the rockers are on and torqued properly. Try to make sure the valves seal. If they don't move, try adding lubricant and hitting the valves with a deadblow hammer using a wood block to avoid damage . Eventually they will move and seal.
5. Install the quick-disconnect spark plug into the hole.
6. Connect the hi-pressure sprayer.
7. Place cardboard and/or rags at the bottom and hydraulic the piston out with the sprayer.
8. Works on almost EVERY engine 4-stroke engine ... but not a 2-stroke. No valves to close the breathing capability off.

I've used a 3500 psi washer and it works great. No damage to the parts at all.