OS/Graupner Wankel - It had to happen

I messed up an Enya engine's bearing when I tried to hammer the crankshaft out.
The key buggered up the bearing, but I did get the crankshaft out. And I didn't lose the key.
The plus side was the bearing needed to be replaced because it was rusted and didn't move.

You could go to David McIntire's video and click on the area where he has a kitty cat and email him as to what the name of the puller he has?
Just an idea?

Dave is fairly good at replying within a week.

I looked thru my sent emails and found David McIntire's email address.
I'm not too sure that it is current as he moved from Florida to Wisconsin the end of August.

Anyway, here is his personal email address: dmrcflyr@gmail.com

Battery terminal or wiper arm pullers are popular for pulling drive hubs. I have an old Armstrong similar to this one, https://www.ebay.com/itm/115620040333 Mine has slightly longer arms and is bolted together.

gkamysz wrote:Battery terminal or wiper arm pullers are popular for pulling drive hubs. I have an old Armstrong similar to this one, https://www.ebay.com/itm/115620040333 Mine has slightly longer arms and is bolted together.

Thanks, that may do it. I might have to grind a bit off the ears to fit the groove but I'm sure it would do it.

rsv1cox wrote:

gkamysz wrote:Battery terminal or wiper arm pullers are popular for pulling drive hubs. I have an old Armstrong similar to this one, https://www.ebay.com/itm/115620040333 Mine has slightly longer arms and is bolted together.

Thanks, that may do it.  I might have to grind a bit off the ears to fit the groove but I'm sure it would do it.

Not that you couldn't buy a new one, But you could checkout a local AutoZone, Advance Auto or O'Reilley Auto Parts store ( if ya have one nearby) and check one out of their tool lending library. I just used a Tap and Die thread chaser set from O'reily $105 deposit on CC, full credit upon return of tool kit. Thread chased and cleaned. I Didn't wanna spend $30 for a one-time use tap.

Marleysky wrote:

rsv1cox wrote:

gkamysz wrote:Battery terminal or wiper arm pullers are popular for pulling drive hubs. I have an old Armstrong similar to this one, https://www.ebay.com/itm/115620040333 Mine has slightly longer arms and is bolted together.

Thanks, that may do it.  I might have to grind a bit off the ears to fit the groove but I'm sure it would do it.

Not that you couldn't buy a new one, But you could checkout a local AutoZone, Advance Auto or O'Reilley Auto Parts store ( if ya have one nearby) and check one out of their tool lending library. I just used a Tap and Die thread chaser set from O'reily $105 deposit on CC, full credit upon return of tool kit. Thread chased and cleaned. I Didn't wanna spend $30 for a one-time use tap.  

That's a thought too. Another one is my son, if I don't have it, he usually does.

Hi rsv1cox,
I am enjoying this post. Thanks.
Any chance putting hardwood wedges between the case/drive washer ?
Pressure over time and heat/cold cycles has worked for me before. Takes time, but has popped the most stubborn things.
(just don't douse in DW-40, and use a propane torch ! Got that t-shirt !)
I am interested in the inner workings of that engine.
No piston? It will never work was the opinion of when it was new.
The one I saw ran great.
Equal to a 'modern' OSFX.25 in my estimation.
A 'Wankelized' Ford Tri-Moter would be pretty big.
I am sure Henry Ford would approve...
I'll sit back now,
And watch a Master at work...
Thanks,
Dave

Is this of any help?

Hi OVERLORD,

With those plans, you made this way more interesting !

Thanks,
Dave

Thanks Dave, Lieven, and Levent.

59" WS on the Ford Tri Dave. I think about right for the three .30's Wankels.

I tried the wedge thing, but I can't even get a razor blade in there. My go-to heat anymore is a butane torch. Pin-point heat right where you need it. Invaluable in loosening the brake line fittings on the RX-7.



I'm learning about these Wankels, both big and little right along with everyone else.

Bob

Bob, this tool is out of stock but you can fabricate this tool as one-off for Wankel engine measurements

Be careful referencing the PI version of the OS Wankel. While much of it is the same, a few parts are not. Obviously, there is the peripheral induction. Other than that, the counterweight screw in the PI is a left hand thread with a large slotted head. I do believe the rotor/seals/springs are the same. I don't have the first version so don't know any other specific differences.

The hub has a key and no taper, so it really should just come off with enough heat to soften the castor goo, or a little help from a puller.

Bob, I have an idea of my own that I apply to my MVVS 58 cc engine, give me a few minutes and I'll show you right away.

"The hub has a key and no taper, so it really should just come off with enough heat to soften the castor goo, or a little help from a puller."

So true.

I am an impatient person, and a not so intelligent one.  A bad combination.  I also do not like being defeated.  So with a buffer nut off my OS LA 40, some heat, a tapping hammer and a vice..............



Which revealed gobs of solder.


Which just popped off, revealing ........... nothing.  Beauty and the beast.







Oh, now I see...........solder came from the holes in the drive washer melted by the heat.  Balancing I would think.  May have to put them back.  I will have to check the video, or maybe a PO mod.

Edit: Checked the video. At 1:11 shows a counterweight.

Bob, once something similar happened to me with my MVVS 58cc, I give you the details of how I did it:
1- With an iron, make a U just the diameter of the anchor of the piece to be removed.
2- Place the flat iron in the bench drill.
3- Place the Wanquel motor on the plate, just where the part to be removed fits.
4- Apply temperature to the piece of aluminum alloy, it will expand perfectly.
5- Apply lubricant
6- Apply the torch to the piece of aluminum alloy again.
7- Now press the mandrel closed on the crankshaft.
8- If it does not loosen, repeat the operation.
I bet he does it in a few minutes!

Yes Bob, the (planchuela AL AL) Fhoto 1, is also used to carry the heat elsewhere and thus the engine is not directly transmitted.
Now it will be a matter of placing a propeller and balancing the system...nice little precision work, friend!

Oh No! I guess that's another difference. At least it should be an easy fix. Later versions have cast bronze hubs with counterweight molded in.

rsv1cox wrote:Beauty and the beast.

Bob, for a 4-cycle, the .30 Wankel is very compact when compared with your OS .40LA R/C engine.  

rsv1cox wrote:

Bob, shades of exposure to water moisture, a quaint reminder of my Stallion .35 restoration 4 years ago. Would be interesting to know the history of what caused the engine to be so rusted. Was it a field find? Makes me wonder.

Fortunately, someone didn't bead blast the rust off and tried to pass it off as earlier OS casting technology with "surface casting imperfections (occlusions)", like they did with my K&B .35 Stallion buy.

https://www.coxengineforum.com/t12115-kb-35-stallion-acquisition

Cleaned up crankcase with corrosion removal.

Steel fin cylinder shows considerable surface rust.

Piston is rusted all over similar to Bob's OS Wankel rotor.

Inside of crankshaft and counter balance weight shows surface rust.

Certainly seems both engines took a similar damp path during their life.

gkamysz wrote:Oh No!  I guess that's another difference. At least it should be an easy fix. Later versions have cast bronze hubs with counterweight molded in.

Pretty apparent which holes were filled. Removed the Woodruff, heated the shaft and tapped it out. Pretty sticky. Berryman's and lightly applied low-volume compressend air sandblasted (aluminum oxide) should make a big difference. Bearings pressed out or protected of course. New seals coming.





#3 arrived today. Well packed again. Some people just know how to ebay. Locked up, but I didn't force it. Perry carb, must be a PO substitute? One fin relieved for the fuel nipple.





I will be interesting to see if this one differs. Maybe just heat the shaft instead of the drive washer.

Between these and the RX-7 adventures this morning, I'm bushed. Nap time...........................................

What you have melted is lead and not solder.
The pure lead is heavier than the solder which will have some tin in it.
Newer lead is "lead free".




So, when you balance it use pure lead and not solder.
Looking at your photos and checking where the lead could have melted out.
It looks that the lead was poured into the four holes by the keyway slot. (Two on either side of the keyway slot).
Those also have it where the holes have like a threading to them to grasp the lead so it would retain it and not fly out.
The other hole are smooth and have no ridges in them?

If you need more lead, go to a tire shop/garage and ask for the used tire weights. (That is where I get my lead from.)
You could try to balance the prop driver using a propeller balancer.
Like the Du-Bro prop balancer. I have one of those magnetic ones and it doesn't do as well as my Du-Bro.




In the video at 1:06 shows where the counterweight should be. On the side of the keyway.

For the lead weights poured embedded in the balance holes to melt meant the engine severely overheated. Someone had mentioned, forgot who (sorry!) that he saw a cowled scale aircraft severely overheat, ruining the engine.

This may explain the severe rusting of the rotor. With all the oil content cooked off, there was no residue oil to protect the rotor and inside of the cylinder chamber. Over time, water moisture took its toll in corroding the unprotected steel surfaces.

Earlier Wankel requires a higher content Castor based fuel. Similar to the Coxes, I'd think that today one may be OK with a 50% Castor and 50% Synth mix, but with that said, one is on their own to find out. Engine is expensive enough that may not be worth risking since it is easy to cook.

2001 instructions state, "FUEL. For this engine, use top quality methanol-based model engine fuel containing approximately 25% castor-oil and between 5% and 15% nitromethane."

2006 instructions for the Type II state, "FEATURES. o Commercially available top-quality model engine fuel containing 15% oil, either synthetic or castor, can be used." It must have had some changes to its metallurgy (or perhaps they chrome plated the surfaces?) to tolerate standard R/C fuel mixtures.

The apparent tendency for the earlier version Wankel to overheat and its unique metallurgy may explain the required higher Castor oil content in the fuel. I am told that similar requirements for the K&B Sportster Schneurles requiring higher Castor content fuel, not the 2% Castor and 16% Synth in standard R/C fuels just don't cut it either, and one similarly does not overheat this engine either, for similar catastrophic results.

I only speculate, but wonder if this Wankel was run on modern R/C fuel with low or no Castor oil content and was run lean, or perhaps was cowled in, or perhaps a combination of the two.

Bob, if you can restore this damaged engine to a decent runner will mean you are a genius!

The old McCoy and Fox stunt engines required 25% castor oil.
If you didn't, they would cease up and score the piston/sleeve.

Those engines loved the oil like a slobbering mouth on a dog and it took 1/2 a roll and 1/2 the bottle of cleaner to clean your plane off at the end of the day.