Help with Royal engine
 

I posted this in another forum but was told it would be better here. As some of you may know I'm repairing a plane that I inherited after my Father-in-law died. I decided to tackle the engine tonight. I wanted to do a complete tear-down. The engine was completely frozen from years of not being used or cared for. I used a gun cleaning oil (it was all I had) and with the help of a strong screwdriver was finally able to get it turning freely. I can see that the rear bearings need help if not replacing all together. This is where I got stuck. I cannot get the con rod off the crankshaft so that I can pull the piston and crankshaft. I also cannot get the front bearing out. How do I get them off/out?

RE: Help with Royal engine
 

Try Marvel Mystery Oil. You can get a pint at any Walmart for about $1.50. It will loosen up any gum or sludge, and provide protection and lubrication.

Usually you must remove the cylinder sleeve to get the con rod off. Removing the sleeve often gives you just enough room to pop it off the crank pin. The rod must slide freely back and forth on the piston pin as well, so that may be another place to look that could be frozen up. Once you get the con rod off and the piston out, a little tapping with a piece of wood on the tip of the shaft will get the crank out. Lay the case on the back plate surface (with the back plate off, of course), get a little piece of wood to hold onto the tip of the crank, and tap it lightly with a hammer. The crank should fall out.

To remove the bearings, heat the case (with all other parts removed) in an oven - just 250 degrees or lower, and use a wooden dowel at a slight angle and a tap with a small tack hammer. You'll find you can place part of the dowel on one of the races - enough to give it a soft tap with the hammer. The goal is not to damage the case or the bearings when you do it!

RE: Help with Royal engine
 

Good morning Tony :
You're doing GOOD, see, you already got one good answer.
Because I chose to not mess around with engines, out of my league, I have always sent mine up to a man in Connecticut. You get the engine back, returned to brand new condition for a very small amount of money. He has done many for me and I find it very convenient.
You can ask for a price quote.....
B.J.'s MODEL ENGINE SERVICE
Repair. Tune-up, Overhaul. Crash Damage
All makes & sizes. 2 & 4 Stroke. Gas & Glow
or go to :
www.starcomposites.com/BJModelEngines
In fact, the Magnum .80 on the plane that took your Glider up, was redone by him.
There is no better place.
RICK

RE: Help with Royal engine
 

The crank needs to go forward slightly. Take the screws out of the front housing in case the crank is tight on the front bearing. Turn the engine to TDC. Tap carefully on the rear end of the crank and it should go forward enough to free the crank pin from the rod.

You might consider freeing the cylinder and removing it first. Turn the engine to BDC and insert a piece of wood in the exhaust port. Turning the engine towards TDC should free the cylinder. Don’t bend anything.

Bill

Don’t pay any attention to me. I put one together backwards this morning.

RE: Help with Royal engine
 

Ok I finally got it apart today. I really had to knock the crap out of it to get it free. I still can't get the rear bearing out yet. It's stuck pretty good. I'm going to soak it overnight in some carb cleaner to see if I can get it free.

How critical is the finish INSIDE the carb body? During my attempts to remove the carb rotor I appearantly created a small burr on the rotor. When I reinstalled it to help work some of the gunk inside the carb body free I created some small scratches inside the body. Are these going to affect it much?

It's really beginning to get to the point that it will be easier and cheaper to just replace the whole engine. I just really want to see this one work.

RE: Help with Royal engine
 

The carb rotor and its barrel need to be free of burrs and move smoothly. A little heat may help with the rear bearing. I use a propane torch.

Bill

RE: Help with Royal engine
 

As soon as I can get to my sandpaper (400 or 600 grit) it sill be free of burrs. I don't think I have anything finer than that. It should work just fine. I don't have a torch. Can I put it in the oven? I was thinking as long as I don't go any higher that about 250 degrees I should be fine. Maybe my heat gun set on high would work better.

RE: Help with Royal engine
 

Never used the oven so I don’t know. However the heat gun might work and it doesn’t cost anything to try. Set the front housing on wooden blocks before heating so the bearing can be tapped with a wooden dowel or punch when warm. The aluminum grows considerably faster than steel and it should not take much heat. Don’t get the bearing crooked in the case.

RE: Help with Royal engine
 

Engine problem fixed. I never did get the rear bearing out but with a little (almost half a can)of Liquid Wrench type stuff was able to get it turning very freely. Now I just need to get a parts pack and ratchet from Tower and it should be good to go.

RE: Help with Royal engine
 

Repairing engines is probably not based on simple economics. The learning process and satisifaction of knowing that you can do it is its own reward like lots of other modeling activities. Bearings and gaskets are usually about $25.

It will be important to bench run the engine since there were a couple of questionable areas (carb barrel, bearing). It is remarkably easier to zero in on an engine problem when it is mounted to a sawhorse or picnic table. Also if it should malfunction or start to lock up the probability of catching the problem before damage is good. A simple flat 1/4 plywood engine mounting plate should be simple to make. The height of the fuel tank relative to the carb centerline will also be important.

RE: Help with Royal engine
 

Repairing engines is probably not based on simple economics. The learning process and satisifaction of knowing that you can do it is its own reward like lots of other modeling activities. Bearings and gaskets are usually about $25.

Yeah, I just love takin' things apart! If I can get 'em back together properly that's a bonus. [sm=lol.gif]
I think all I need now is the gaskets and a ratchet clip. I may have to replace the carb body too. I found a crack where it goes down into the crankcase.

RE: Help with Royal engine
 

Royal engines were notorious for breaking the carb mount casting and the muffler screw threads in the main case when crashed. A carb probably cannot be purchased. Maybe you should consider making friends with JB Weld. JB Weld is a 600-degree epoxy that has been used for at least 50 years to repair almost everything.

RE: Help with Royal engine
 

Oh yes, JB and I are very good friends. I think I still have some left over from another project. I understand that parts will fit most Royal engines. More specifically the O.S. SF series. The O.S. 4D carb body should work if it comes to that. If it leaks I'll try JB. If that doesn't work I'll try the 4D carb body. If that doesn't work I'll just put the spare .40 that I found in my box of parts on it. Thank you again for all you help thus far.