Mike SVOR

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A friend asked me to try and get this thing running.
It was completely locked up.
I soaked it in nitro over night, and got the motor to turn over after removing all valve train components.
I can't get the cam shaft out. I need to know how to do this. I've removed the side cover and it won't come out.

I need to get the sleeve out so I can clean the wrist pin and bearings.
How do I take the sleeve out? There doesn't seem to be any area to stick a flat head screwdriver in there to pry up.
ARRGH!!! hehe

I'm giving this one a 10% chance of being rebuilt.

[&o]

Bax

My Feedback: (11)

To remove the camshaft, you must remove the cylinder head, remove the pushrods and pushrod tubes, and then remove the cam followers (lifters). Then, you can slide the camshaft sideways, out of the engine.

To remove the cylinder liner, you must remove the rear cover, and push it up from there. If it's stuck, you may need to heat the crankcase with a heat gun to expand the aluminum a bit.

Mike SVOR

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Thanks for the fast reply.
I got the camshaft out, seems it was just stuck in the inner bearing.

All the internals are coated with 10 year old caster oil nitro from not being maintained correctly.
I have the motor soaking in a bucket of gasoline atm.

the cylinder liner wont budge.
Is there any info you can give me on this beyond what youve already stated?
Vice grip pliers on the upper lip?
heating the case
cooling the liner with an ice cube...
etc
know of any threads floating around you can point me to?

Thanks!

w8ye

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I don't have much hope for that engine after the prying with screw drivers and the gripping with the vice grips and channel locks.

You need to throw those tools away

Mike SVOR

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Well, the Q-tips kept breaking every time I tried to push the cylinder sleeve out. And the cotton balls didn't really help when rubbed across the top of the piston.
I did try to talk sweet to it and give it loving, encouragement. But it continued to sit there, still needing disassembly.

gkamysz

My Feedback: (19)

Here's how I do it.

http://www.dieselrc.com/howto2.html

If you've already used channel locks on the liner flange, the top of the flange is probably burred. If the cylinder isn't out of round (it would need to be measure with a bore gauge), you can clean up the top of flange with 400 grit or finer sandpaper on a flat surface.

If it's really glued together with castor only heat will help. Acetone makes for a good solvent for castor, but even it can't get between the liner and crankcase. Gasoline may soften the castor, but it may not.

spaceworm

I am not absolutly sure, but I don't think gasolne will disolve castor residue. Try methanol. You mentioned soaking in nitro, as in nitromethane? Nitromethane is a good solvent, but maybe not the choice for this chore. Again try methanol. NOT while you have it wet with either gasoline or nitromethane or even methanol, try heating it up with your Monokote heat gun or even in the oven, NOT microwave, at 250 degrees F or so. Good luck and please do as W8YE says and toss your visegrips and channel locks and pry bars.

Richard

Mike SVOR

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thanks for the replies you guys

I really liked the vid. Very good quality.
Liked how you took off the valve keepers.

This motor is old. It doesn't have a wrist pin hole to remove the pin.
Everything on it is crusted.
the camshaft area is filled with hardened tar that looks like the color of rust, but hard like fossilized amber.
the lifters are stuck in the bores. but they'll come out after a little more soaking.
the cam lobes are ok.
the crank counter weight is covered in surface rust and the bearings are died brown with rust or tar, (who knows).
The piston's wrist pin has visible rust on it and won't slide back and forth.
Currently, it is frozen to the piston and the cause of major resistance when trying to turn the crankshaft.
If I could get the sleeve out without damaging it, I think it has a chance to run again.
But I don't want to start damaging parts, cause I don't want to put any money into this thing.

Ever have something someone has given you for free, and you like that thing, but just wish you could punch that person in the neck for not taking better care of it?

I always wanted a 4 stroke motor, but i have my doubts i can bring this one back from the dead without putting more money into it than I care to.
Know what I mean?

why can't my cylinder sleeve just slide out like in that movie?!! hehehe

proptop

My Feedback: (8)

Your engine reminds me of an O.S .61 four stroke that I inherited...
It had been on a float plane that got dunked, and not run long enough afterward to burn off all the moisture inside. It sat for a couple decades, and was locked up solid with rust.

Anyway...
I have a feeling that you are gonna need a bit more heat to get the sleeve to release. You might also need to set-up block of wood (2x4 or 2x6, etc. ) with a hole big enough for the sleeve to drop down through. Heat the %&$#@! out of the case and use a piece of hardwood dowel or something similar to drive the sleeve out. Put the case so the head flange is down, and put the dowel through the backplate opening, so it catches on the lower lip of the sleeve, and you can tap on the dowel w/ a light hammer.

As far as soaking...the crock pot of antifreeze has always worked well for me...then a lot of PB Blaster on the wrist pin and other parts can help to loosen them up.

gkamysz

My Feedback: (19)

Some engines don't need the hole to remove the conrod and piston. The FS-91 is one. The FS-26 even though it has a hole doesn't need it.

Heat the engine. That's all it takes to get the liner out. even in the most gummy engines, a little hotter will soften the castor and it will come out. Use a popsicle stick to push on the lower edge of the liner from inside the crankcase.

If you really have that much rust in the engine, it's probably not worth it. If you've never cooked glow engines in green antifreeze, do a search here, it does wonders for old castor.

Campgems

There is a thread on tearing down an O.S 52 four stroke and re-assembly. Almost everything is exactly the same.

An important point is that nothing was "pry-ed" into place, so absolutely no Prying should be use to dis-assemble it. There are stubborn spots in tearing down this engine, or any four stroke. Especially a well used one that is stiff with old Castor.

A few points to keep in mind. While it is difficult to get the cam out without removing the head, it is still easy to get it out of time once the bearing cap is off.

I'll give you mynickel tour of taking it apart. I'm assuming a full tear down and bearing replacements.

First remove the rocker cover and you willl find a singlesocket head cap screwbetween the rocker arms. Take it out. The rocker arms wilnow lift outas an assembly. You can now dump out thetwolifters. At thispoint, you will remove the fivecylinder head socket head cap screws. When they are in you hand, then slight twist the head with your hands. this will break the head gasket seal and allow the head tojust lift off. Set it aside. Humm,got to back up a bit here. Iforgot to remove the carb and intake manifold. Two screws holding the carb to the back plate, and two screws holding the intake to the head. They go first.

Now at the back plate, remove the four screws and give it atwist and remove it. The O.S. machining isreally good, so there will be no gaskets,DON"Tpry things apartas gaskets will be need if you do andyou will have to make them. What you now have inhand is a bear crankcase,crank shaft cylinder lining, piston and rod.Up front the prop hub is probably still there, I don't remember at thispoint ifitis held with a tapered sleeve or a woodruff key. It doesn't reallymater at this point.

Theback plate is clear.The headis off. The next step is toraise, not remove, but raise the cylinder lining. You willsee a hole in the back ofthe crank case. This is where you access the wrist pin. If you are reallylucky, you can grabthe calender sleeve with one of the rubber pads for taking lids off cans and jars and see if you can turn it a little. Probably not. You should next try your covering heat gun and warmthe case up some. Some leather gloves are good here because you want thinghot. Try again to twist and lift the lining. When that fails, get a Craft Stick, better known as a clean Popsicle stick. Use the as your punch to break free the cooked oil on the sleeve. NOBIG HAMMERS, light tapping will do the trick.Once you have the sleeve moving , lift it up just enough tofully open the hole in the back of the crank case.This is the hole that the wrist pin will be removed though. Firstcrank the engine over so thewrist pin is showing in the hole. Use adrywall screwwithyour fingersandturn itinto the holein the Teflon cap. Once it grabs, pull the cap out. Now, come the most difficult part, pulling the wrist pin. With any luck, you should be able to use the same drywall screw and turn it into the wrist pin using some down pressure. when the pin starts turning, keep screwing the screw in, but now be pulling it as you turn. That should lift the wrist pin out.

At this point, pull the cylinder liner with piston still inside out. Don't separate these two items. You can then assess theconditionof the bearings and decide if you needto replace them or not. Usually, if I've gone to this much trouble anothersmall amount of time and $10 or less will allow me to put in anewset of bearings. The main and nose bearing are not much problem, but getting the cam bearings out can be. If you need instructions on the bearings let me know.An oven and a freezer makse life easy there.

Assembly is just reversed of disassembly. The reason I don't remove the piston from the sleeve is that the ring fragile and once it is free of the cylinder, it is easy to break it putting the piston back in. It the piston never clears the sleeve, this isn't an issue. The probability of needing to replace the ring is small unless you have several hundred hours on the engine. Same for the valves. They are best left alone. Any attempt to
"reseat" them will just cause problems. They are precession machined and require no grinding or seating as we use do have to do with our old cars. .

Don

Mike SVOR

My Feedback: (1)

Just when I think message boards cant get any dumber...... you guys go and type out instructions like these.....































































AND TOTALLY REDEEM YOURSELVES!!!!!!! (hehe, dumb and dumber movie)

LOL,
I put it in the oven at 275 degrees for 30 minutes as instructed, took it out with my welding gloves and tapped on the inner side of the cylinder liner using an aluminum dowel rod. The liner popped right out.
The bearings remained frozen though.
I soaked the engine in 93 octane gasoline and 2stroke mix overnight.
After working at it for about 20 minutes, I finally got the rear bearing to move about 1 degree back and forth. I continued to spray brake cleaner into the bearing while wiggling the barrel back and forth.
It finally started moving about 20 degrees back and forth, then all the way around. Took about an hour of playing with it.
The inner cam bearing seems ok and I got it working and spinning too. Havent messed with the outer cam bearing yet, but it seems to move.

So far, everything is apart and lying on my kitchen table. All parts are covered in after-run oil.

This is by far, the worst condition engine i've ever attempted to save. It may be sucessfull too!
I gota read up on how the oiling works in these engines.
I can't believe that the crankcase stays empty with no oil in it. Just the few drops you put on the bearings when assembling it?
And why doesn't all the oil drain from the camshaft area into the case?
questions, questions, questions.....

blw

My Feedback: (3)

Everyone took time explaining various methods to get the job done...........

Mike SVOR

My Feedback: (1)

[sm=thumbup.gif]
I sincerely thank you guys for the info.
I never had to bake an engine to get the sleeve out before, so this was my first.
If I get it running, i'll definetly post vid.

In total, my friend gave me 3 engines to get running. Two 2 stroke engines and this one 4 stroke. They were all siezed up the same way, but not as bad as the 4 stroke.
The two 2 stroke motors started up sunday afternoon on my test stand and ran perfectly.
My friend is going to give me this 4 stroke for fixing those two 2 strokes!

All 3 motors required baking in the oven to remove the sleeves and pistons.

You guys really helped me out!

Thanks,
Mike

Campgems

The Four strokes get lubed by blow by from the piston. I'm not sure about that exact engine, but the two O.S four strokes I've had apart( a 52 and a couple 120's) have a hole in the center of the crank with a vent crosshole at the cam drive gear. The blow by migrates through this hole and provides direct lubrication to the cam and lifters, camand nose bearing.The excess is vented out the crank vent. The top end is lubed also by blow by on the valves. This keeps the rockers and push rods lubed. There is no path from the top end to the crank case on these engines.Magnum and Saitos usually have an open cage main bearing and the lube migrates forward through the bearing forward. The Saito's have a lube problem on the cam and lifters. Some guys have run the crank vent into an added nipple on the cam housing and a send nipple added to the other side of the housing for the final vent. This way there is a flow of oil through the cam area. Saito recently introduced lifters with a spiral grove lengthwise to allow the excess top end oil to drain into the cam area.

If you study the modifications to engines, IEthe Surpass line, you will see that there are changes to the crank vent to improve overall lubrication of the engine. IEthe crank vent on the 1.20 Surpass I an Surpass IIwas behind the cam, but the Surpass IIIis ahead of the cam. This ensures a flow of oil through the cam area. Saitos either vent at the back plate or in the crank area, so there is Little in the way of flow through at the cam, only migration.

As to why there was no oil in the engine when you tore it down, I have no explanation to that other than it must have set on the shelf for a long time and dried out. If the engine runs and there is oil in the fuel, there will be oil in the crankcase.

My O.S 52 four stroke was mounted in the last plane at almost inverted. It picked up a nasty habit of running just awful for the first couple minutes for the first start of the day. Ifound out why one day when I decided to check the valve lash. When I took the rocker cover off, there must have been a teaspoon of oil setting in the bowl. The inverted setup left a huge puddle of oil trapped around the valves and until the engine got warm and vaporized the oil with rocker movements, it was getting sucked into the intake and the engine was smoking like crazy. Every day was like that until it got warmed up, it ran great.

Don.

Mike SVOR

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this should say everything
http://www.youtube.com/watch?v=ECUXzHL72PQ


IT RUNS!!!!

Ran on 30% synthetic heli fuel 20% oil
It was pumping oil out the breather vent and was purring pretty decent for the tune i have on it right now.

facab

Here I share some pictures of the modification I did on a Magnum XL91, 1mm diameter hole between valves cam and intake cam plus the modification on the crankcase to allow the oil to go up to the valves cam.