John Deere Engine

[radfordc]

It looks like I can use the cheap 48 pitch spur gears from one of the R/C car suppliers. I'm looking at a 17 tooth pinon and a 34 tooth cam gear with an idler of the right size to fit between. These gears seem to have about the right diameters to fit.

I had not given proper thought to needing lifters for the pushrods. I was thinking of just polishing the ends of the pushrods to run directly on the cam. Obviously, that's not a great idea. I will make up a set of lifters.

I will post a picture of what I have so far. I'm a long way from done. I started on the crankshaft last night. I cut out the crankshaft blank from a 1.5" diameter steel rod...that was a chore. Hope I don't mess up when turning the crank as I don't want to have to do that again!

Charlie

 

[cfellows]

If that's a 1 1/2" diameter round rod, you're going to have a lot of swarf by the time you get a crankshaft carved out of it. I used a piece of cold rolled steel, 1.25" x 3/8" for my crank. But, if that's what you've got on hand, that's what you use!

Chuck

 

[radfordc]

Here is where I was two days ago. Tonight I did screw up the crankshaft so I'm starting over on that.

 

[cfellows]

Nice work. Sorry about the crankshaft... they can be ornery!

Chuck

 

[radfordc]

OK, that's better!

 

[cfellows]

Now you're cookin'! The crank is the trickiest part.

Chuck

 

[radfordc]

What's strange is that I messed up the first crank and still don't know what I did wrong?

Instead of turning the rod journals between centers, I used an offset holding fixture (see picture attached). I drilled the offset hole exactly .437" off center...equal to the crank throw. When I started cutting the journal I found that the throw was much less than it was supposed to be...on the order of .250-.300". Afterward I went back and tried checking my setup and couldn't figure out what I did wrong as the test piece came out correct.

On the second crank I turned between centers and all came out as expected.

Charlie

 

[radfordc]

Finished the bearing mounts.

 

[cfellows]

Nice progress. Did you use CNC to mill out the block? You did a nice job.

Chuck

 

[radfordc]

No CNC here, unfortunately. I used a drill to remove most of the material and then a 1/2" end mill to finish. I have DRO's on the mill which make it much easier to sneak up on a measurement.

Charlie

 

[cfellows]

No CNC here, unfortunately. I used a drill to remove most of the material and then a 1/2" end mill to finish. I have DRO's on the mill which make it much easier to sneak up on a measurement.

Charlie

Gotta get DRO on my mill! I keep thinking about it, but have just kept putting it off!

 

[radfordc]

With the amount of backlash in my mill I wouldn't be able to work without the DROs. I bought digital quills from an ebay seller and mounted them myself. I think the cost for two quills (8" and 6") was only about $60 or so.

 

[radfordc]

A little more accomplished today.

 

[radfordc]

Completed the head, pistons, and rods.

 

[cfellows]

Did you figure out where all the holes go?

Chuck

 

[radfordc]

Yes. After you posted the info on the valve it all started making sense. I did goof up on the head the first time, but the second one turned out perfect.

Charlie

 

[radfordc]

Some guys on another thread asked me to post the drawing I made of this engine. Its in the plans section.

Charlie

 

[Metal Butcher]

Some guys on another thread asked me to post the drawing I made of this engine. Its in the plans section.

Charlie

Hats off to Charlie. :bow:

Charlie, thank you for taking the time to provide drawings for a guy like me that doesn't have the necessary drafting skills or computer programs. With out this information building can be very difficult, and I imagine most builders would just scrap the project.

I was able to down load-and-print the plans.

-MB

 

[radfordc]

Finally got back to doing some work on the engine. After the NAMES show I had "honey do's" until tonight. The flywheel is finished.

Charlie

 

[radfordc]

More work done this week. Got most of the fiddley bits done. The gears were purchased for $3 each from an R/C car supplier.

Charlie