Author Topic: 5 Cylinder radial somewhat based on the Morton but not much  (Read 11518 times)

Offline gbritnell

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5 Cylinder radial somewhat based on the Morton but not much
« on: March 15, 2024, 12:04:22 AM »
I thought I had started a thread on building another radial engine. The first one I built years ago I donated to the Sherline Craftsmanship Museum. I really enjoyed running it for people so I thought I would build another one. On the original design I had incorporated a feed/scavenge oiling system. It worked but I wasn't happy with it. I went back to the plans I have for the Morton M5 and to see how they fueled it. The carb feeds the crankcase with a gas/oil mixture which is then drawn through the back of the crankcase and out the intake pipes to feed the cylinders. On it's way the mixture lubes all the internals. I went a similar route with this engine but in the part of the crankcase that the intake pipes emanate from I designed a blower fan to help feed the cylinders. Everything else about the engine is the same as my original design. I searched for the original thread but couldn't find it.
The following posts show the machining of the rear cover which holds the distributor, the intermediate crankcase housing where the fan resides and the main crankcase.
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Offline gbritnell

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Re: 5 Cylinder radial somewhat based on the Morton but not much
« Reply #1 on: March 15, 2024, 12:06:02 AM »
More pictures.
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Offline gbritnell

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Re: 5 Cylinder radial somewhat based on the Morton but not much
« Reply #2 on: March 15, 2024, 12:07:46 AM »
3 more pictures
In the 3rd and 4th pictures of the second posting I placed a scale next to the parts so you can tell the size.
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Offline steamer

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Re: 5 Cylinder radial somewhat based on the Morton but not much
« Reply #3 on: March 15, 2024, 12:19:03 AM »
Great progress on the "Morton-esqe" build!  And thank you for sharing it here!

I'm watching along, and taking notes.   

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline crueby

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Re: 5 Cylinder radial somewhat based on the Morton but not much
« Reply #4 on: March 15, 2024, 01:30:26 AM »
Wow. Following  along here!   :popcorn: :popcorn: :popcorn:

Offline Kim

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Re: 5 Cylinder radial somewhat based on the Morton but not much
« Reply #5 on: March 15, 2024, 04:30:05 AM »
Beautiful job, as always, George!

I just love seeing your milled 'castings'.  :popcorn: :popcorn:


Kim

Offline petertha

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Re: 5 Cylinder radial somewhat based on the Morton but not much
« Reply #6 on: March 15, 2024, 06:23:16 AM »
On the original design I had incorporated a feed/scavenge oiling system. It worked but I wasn't happy with it. I went back to the plans I have for the Morton M5 and to see how they fueled it. The carb feeds the crankcase with a gas/oil mixture which is then drawn through the back of the crankcase and out the intake pipes to feed the cylinders. On it's way the mixture lubes all the internals.

Nice work, following along!

What specifically about your oil feed/scavenge system were you not happy about? Do you have any old pictures, or can you describe it?

FWIW my Ohrndorf O5 radial lubrication system is similar to what you are describing as an alternative, but with no distribution fan. I can tell you from my initial teardowns that the mist method thoroughly wets & lubricates the internals. However if I didn't swiss cheese the cam plates & front gear plate with aperture holes, I'm not confident I would have sufficient lubrication in the nose case where the cams & lifters & gears really need it. The intake charge has to pass through the congested area largely occupied by master rod assembly, counterweight, bearings etc. on its way forward. I'm also running methanol 4S glow fuel containing 18% oil. I did a build post here on the forum so you can check out the discussion & pics there. I think one of the Saito radials had a distribution fan in the rear. OS had kind of a spiral scroll path backplate to direct flow into intake pipes. My understanding of these systems was more about attempting to equalize delivery gas charge returning from the CC to upper & lower cylinders, as the lower ones ran richer (or probably more critically, the upper ones leaner). I thought I read the current Hodgson radials have a rear mixer vane too vs originals did not. Now that's a bigger engine too, so maybe the increased height difference between upper/lower heads factored into this.

Maybe grass is greener on the other side of the fence but I always thought the Forest Edwards 5-cyl pump system was kind of a practical solution, because it directed oil streams where required & then drained away in a sump chamber for recirculation. Its lobe 'bump' style check valve pump might be a bit easier to implement than a gear pump, but I have no experience with either yet. I recall Edwards called for straight methanol or maybe 5% oil, so lubrication was obviously working. That might be more analogous to a gasoline spark engine? I want to build a bench gear style pump to evaluate, but it was too late to integrate on the O5 anyways. Looks like you have more opportunities to integrate a pump off rear drive shafts. I'm still  bit apprehensive about my front idler gear assembly because its not really in the line of mist flow & the axle is even more hidden. I've drilled some lubrication bleed holes between the teeth, similar to all the rod bushings to help get oil into every nook & cranny. Squirting oil seems like a more sure fire way even though its more complicated mechanically. Mist is net simpler. Anyways, look forward to what you come up with.

Offline fumopuc

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Re: 5 Cylinder radial somewhat based on the Morton but not much
« Reply #7 on: March 15, 2024, 08:14:59 AM »
Hi George, what a pleasure to follow it.
Kind Regards
Achim

Offline cnr6400

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Re: 5 Cylinder radial somewhat based on the Morton but not much
« Reply #8 on: March 15, 2024, 11:22:53 AM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Offline Jasonb

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Re: 5 Cylinder radial somewhat based on the Morton but not much
« Reply #9 on: March 15, 2024, 01:52:07 PM »
Looking good George, you did post quite a few photos of the previous one starting in this thread

https://www.modelenginemaker.com/index.php/topic,8172.msg237533.html#msg237533

Offline gbritnell

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Re: 5 Cylinder radial somewhat based on the Morton but not much
« Reply #10 on: March 15, 2024, 02:52:18 PM »
Thanks Jason, I thought I looked everywhere but couldn't find it. I was certain that I had posted when I was building the previous engine.
 
Peter, I looked back through all my photos of the first build and I only have pictures of the exterior of the pump with the feed and scavenge lines hooked up. I guess my reasoning for eliminating it was the amount of extra work to build and plumb it. It worked well but actually too well. I had trouble regulating the amount of oil. I put several reducers in the line but never knew exactly how much oil was being supplied.  It was a 2 stage pump driven off of the gears that operated the distributor. Picture of the actual pump are attached.
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Offline gbritnell

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Re: 5 Cylinder radial somewhat based on the Morton but not much
« Reply #11 on: March 17, 2024, 03:31:38 PM »
I finished up the blower fan. I started with a disk of brass and mounted it in the chuck. I needed a .062 (1.59mm) slot for a key. Not having anything that small here's how I achieve that. I first drill a .062 hole at the edge of the bore radius. I then put in the bored hole. This leaves me a half round hole at the edge of the bore. For thinner parts I then file the hole square. With thick parts where they can't be filed squarely all the way through I just leave it as a half round and make the key accordingly. The radius at the root of each blade was drilled .094 (2.38mm) Then using a .094 4 flute end mill I machined the stock to create the individual fins.
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Offline gbritnell

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Re: 5 Cylinder radial somewhat based on the Morton but not much
« Reply #12 on: March 17, 2024, 03:37:10 PM »
The next pictures show the keyway in the slave shaft and the slave shaft, main crankshaft and master rod. The main crankshaft has 2 keyways, one for the timing gear and one for the propeller hub. All are .062 square.
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Offline Admiral_dk

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Re: 5 Cylinder radial somewhat based on the Morton but not much
« Reply #13 on: March 17, 2024, 07:47:01 PM »
Some Very Nice parts you have made George  :praise2:
... and I presume that you are more or less finished with this Engine (or working even faster than the Master Elf and his gang)  ;)

I see that you have made a Compensated Master-Rod - and it looks like quite a big compenstion - calculations or Geometry on Paper ?

Per     :cheers:

Offline gbritnell

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Re: 5 Cylinder radial somewhat based on the Morton but not much
« Reply #14 on: March 17, 2024, 10:27:53 PM »
Hi Per,
I laid out everything in my CAD program. I rotated the master rod 72 degrees then used the intersection point of the cylinder centerline and the crank radius to create the rod pin point. I did this for every cylinder and this is what I came up with. My figuring was based on the cam timing. The cam timing is fixed relative to each cylinder's TDC so the piston needed to be at TDC at the same time otherwise the cam events would be out of synchronization.
Talent unshared is talent wasted.

 

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