The Le Rhone 9C

[bent]

Ahh, it's becoming more clear by the day.  Agree, that looks like a cylinder head more than before.  Knowing the valve is "monsoupape" already, I won't have to ask you where the other rocker arm goes.

[Craig DeShong]

Ron, CNR, Ben; thanks for the comments.  Thanks also for those of you who take the time to silently stop by.

Ben:  I don’t believe this is a monsoupape design.  My reading tells me that that design has the intake valve in the piston.  This is a traditional valve design with both valves in the head.  The valves however are actuated with one push/pull rod.

This post starts with making the bearings for the valve rocker shaft.  These are brass sleeves that are installed in the valve rocker support from the previous post.  I got a bunch of these brass threaded rods at the scrap yard a while back.  They are handy for making small parts.  Here I’m reducing the diameter to the OD of the bearing.



Drilling the bearing to accept the rocker shaft.  I’m drilling this bearing undersize. Once I install both bearings I’ll run a ream through both to get both bearings "true”.



The bearing has a shoulder that I’m cutting in this photo.



Parting the finished bearing off the stock.



And then facing the large end to the correct dimension.


After making the other bearing for the opposite end, and installing the bearings and reaming them, the rocker support is complete.



Next to be made was the rocker shaft.  Here I’m turning the diameter to .156 inch.



After cutting the part off then stock. I’ve turned it around in the lathe and am facing the other end.



This end was then turned down to the diameter of the valve rocker.



One last step; cutting a flat so the valve rocker resists turning on the shaft when in use.



That was the end of activity yesterday.  Today I finished the valve components for cylinder number one which I show here.  The penny shows the size of some of these parts.  Lots of piddley, little parts that are hard to make because they’re hard to see.

In the center, the valve rocker (under the penny).  On either side; the valve, valve spring, spring keeper, and spring keeper retention pin.



Below is a photo of the valve parts assembled to the cylinder head.



At the end of the day, with the only remaining task being that of cutting two fins on the head, disaster struck.  I had the head mounted on the lathe and was using a parting tool to cut the fins, as I did with the fins on the cylinder earlier.  Everything was proceeding nicely when the parting tool jammed and jerked the head out of the lathe chuck.  When this happens, you don’t escape unscathed and today was not an exception.  Things could have been worse; the only damage to the head was having a few pieces of the fins I was cutting torn out. 

To ‘fix’ this, I’ll need to make a replacement head and replacement intake and exhaust chambers.  I can probably re-use the valves, springs and keepers. 

Rather than stop and do this I’m going to continue with the other eight heads.  Hopefully, I won’t have any other problems but if I do, I might as well make all the replacement parts at one time.

Plan “B” was to cut the two head fins using my rotary milling head and a slitting saw.



Finally, a view of the completed head sitting atop a cylinder.

[RReid]

Ohh Maannn! That's a real bummer, Craig. Still, the assembly sure does look cool.

[cnr6400]

Sorry to hear about the mishap Craig. Better days ahead. This is going to be a great engine!

[Admiral_dk]

Sorry about the 'lost head' and the 'Blue Words' that followed (I'm sure).

But you have a very impressive result in the last picture 

Per

[bent]

Argh, you are right Craig, I keep using the term incorrectly.  Sorry to hear about the damaged fins...but is the damaged fin the one in your photo?  It looks ok to me, other than a small area of missing fin...

[ddmckee54]

I agree with bent, it looks OK to me.  Besides, we won't tell anybody about it if you won't.

Maybe you can claim it was battle damage?  Which would be entirely true when you thinlk about it for a little while.

Don

[Vixen]

Craig,

Tuck it away, out of sight, in one of the bottom cylinder locations; you have nine positions to chose from. 

Mike

[Craig DeShong]

Thanks for the commiseration, but I had a change of heart this morning and am well into a replacement for the ruined head.  It should just take another good day to get back to where I was prior to the mishap.

You are right though, I could have claimed’’battle damage’ and I’m sure a lively conversation would have ensued. 

While building this model I’ve pondered several times as to what kind of damage a machine gun burst from a vintage gun would have caused to this engine, the cylinders were rather thin.

Mike:  this is a rotary engine.  Where’s the bottom?   

[Craig DeShong]

Thinking a bit more regarding ‘battle damage’.  I remember hearing that many of these WW1 aircraft went down in flames after being attacked.

I would think gunfire might/would cause severe damage to the cylinders.  Even without that, If we inspect the Le Rhône 9C engine


Notice the brass intake pipes at the front of the engine.  These carry fuel/air from the crankcase to the individual cylinder heads.  They would have to be quite fragile, I would think any rifle/machine gun round would pierce them, and when-if that happens, wouldn’t raw fuel be expelled from the break and saturate the engine?  Sounds like a fire to me.  Maybe that is why they were moved to the rear of the engine with the Le Rhône 9J 110 HP up grade?

[Elam Works]

Do not be too quick to write off the pilot of a rotary engine hit by a bullet. The following exhibit is at the W.O. Bentley Museum in Wroxton, UK and shows an early Bentley BR1 cylinder (note cylinder head thread, omitted from later engines) that took an armor piercing bullet.

-Doug

[Craig DeShong]

A hole thru into the cylinder, with the bullet probably clattering around inside the cylinder caused “a miss and a loss of power”.  

[Elam Works]

I found the piston skirt clearances of a Clerget 9B rotary I disassembled to be very generous, so, maybe not so much of a problem! And with an open exhaust port, all things shall pass...

-Doug

[kvom]

Craig,

Tuck it away, out of sight, in one of the bottom cylinder locations; you have nine positions to chose from. 

Mike

Given that the entire engine rotates, there is no bottom cylinder.  But you knew that.   

[bent]

I keep looking at those brass/copper intake tubes and marvel at the thought of a row of tinkers forming them to those complex shapes in a shed somewhere.  Any further thought on a simpler "modern" method yet, Craig?