5 Cylinder radial (winter's project)

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Here is yesterday and today's progress. I finished up the rods, making the bushings and crank pins or wrist pins if you will. Early this afternoon I started on the crankshaft. The shaft itself is 1144 stressproof, not that it needed to be but it's a little stronger and cuts quite well. The crank pin is W-1 drill rod. It was turned, polished, hardened and drawn out a little. It was then presssed and Loctited into the crank.
Every time I get parts made I want to see what they look like together so I pressed the bearings into the cases and took the slave rods off of the master. I inserted the crank and went to put the master onto the crank pin and discovered my first needed modification. The crank pin as designed is too long and won't allow the master to be installed. The master rod is .45 wide and the pin was .438 so I started grinding the pin down about .025 at a time. When I got to .305 the master rod would slip in. The hole in the crank pin is to drive the distributor and oil pump gears through another crank affair driven by the main crank. The original design is for a .125 drive pin but I don't see any reason why I couldn't just use a stub the same diameter as the main crank pin, that way there would be a little more support for the master rod although I suspect .305 would be more than adequate.
The first couple of pictures are of the rods assembled.

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The next 2 photos are of the crankshaft and the last 2 are with the rod and crank assembly mounted into the main crankcase.
gbritnell

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Hi Craig,
I will post some pictures of the Galloway in the engines from castings area.
gbritnell
 
I'm on to the next stage of the engine build, the cylinders. These will be made from 12L14 steel. I wasn't looking forward to this job because of having to cut the very thin fins.
First up was to drill and bore the cylinder. I used a .562 drill figuring even if it cut a little oversized there would be enough stock for the finish bore of .625 With the drilling an boring finished I set the compound over on 35 degrees and put a chamfer in the bottom to start the piston rings.
gbritnell

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I turned the spigot on the end of the cylinder. This will fit into the bored hole in the crankcase. Next up was to cut the first relief on the cylinder. This would create the mounting flange and the bottom of the first fin. I have all manner of .375 high speed lathe tools ground up so I found a necking tool that would fit the bill. First up was to square the tool up and then touch it off to the .75 diameter cylinder hub. I always stay .001 away from the reading when I set the dial as I have found that touching the tool even lightly will overcut the desired diameter. This are is not critical but I try to keep things as I have designed them. For cutting with any type of cutoff or necking tool on a piece of stock this size I go into back gear on my lathe. My belts are in the higher range so this keeps me from having to shift them around for other operations.


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Its still looking great George. Was wondering though in the first set of today's pictures, the third one down...what were you doing with the drill shank inserted into the bored cylinder. Was it to help set the compound or what? Just curious and don't want to miss anything.

Bill
 
With everything ready to go I touched my tool off, set my -0- on the readout and cut the first relief.
Next up is the 'puckering' job. The fins on the cylinder are .031 wide and the spaces in between are .039. Having ground many parting and necking tools from high speed blanks over the year I have found that when grinding by hand I end up with more side clearance and that weakens the tool so this time I took one of my cutoff blades and narrowed it down until I got the desired .039. I ground back about .28 as I had to cut in .200 deep. I squared up the tool and touched it off and prepared for the worst. For this operation I sprayed some of my cutting oil into a small container and used a small brush to keep the oil down in the fins. This is really a job that requires 'feel'. As easy as 12L is to cut it loves to bind up during the necking procedure and I didn't want to make any more of these cylinders than necessary.

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Hi Bill,
You mean the end mill shank? That is my plug gauge. The end mill shank is .0002 undersize so if I just get it to slip in I know I'm right on .625. I also have a tooling dowel that's .0005 over so I use that as the no-go gauge.
George
 
Whew! got the first one done. I could feel the tool start to snag a couple of times so I just backed out a little, applied a little more oil and proceeded. The next shot is 2 down and 4 more to go. I finally got them all cut. Up next was to reinstall the wide necking tool and cut the spigot on the top of the cylinder leaving it a little heavy for the next operation.

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Thanks George, yes that is what i meant. And the fins tured out very well too :)

Bill
 
The next step was to cut the taper on the fins. This was approximately 10* so I set the compound over and put my turning tool back in for this cut. With that complete I took a small triangular file and broke the edges on all the fins. The second photo shows the competed cylinder to this point. Once I have them all made I have to make a mounting fixture up to hold them for the final operation which will be putting .75-40 threads on the top end spigot. As is my habit I just couldn't resist slipping the completed cylinders into the crankcase to have a look-see. Now it's starting to look like something!.
George

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George

The last photo with the cylinders set in really starts to make it look like an engine. Great work as always George. :bow: :bow:

Cheers :)

Don

 
Looking wonderful George
This is going to be a beaut :bow:
Pete
 
I finished all the cylinders with no mishaps. Tomorrow I will make the fixture to do the threading by hand. I have made a hand crank for my 6" Craftsman/Atlas lathe specifically for this job. I'll keep you posted.
George

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Is the crank pin diameter stepped down slightly where it engages the crankshaft web hole?

Is there anything else that keeps the 2 parts engaged, or just pressed in & locktite as you mention?

What amount of interference fit is good in a situation like this & what kind of locktite?

 
George

First of all amazing machining. :bow:

Secondly, I was looking at your last photo and I noticed the distributor. I went back all the way to the start of this thread but could not find any mention of it. Is it an off the shelf item?

Vince
 
Hi Vince,
The cap is a Bruce Satra cap. He sold the caps to S&S Machine and Engineering. They make the small electronic ignitions. They have caps for 4,5,8 and 9 cylinder engines. The rest of the distributor is mine.
gbritnell
 
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