I want to build my first engine

[Makintrax73]

Found free plans and some detailed instructions for an Owen Mate 2cc online. I have RC planes so if this works it might go in a plane.

Here's where I am.....

No casting available, rough cut block from 2"x2" AL stock



Block was first squared on the milling machine then nose turned to 24mm and started at 5/16"......



Backplate was custom threaded at .960" x 24tpi because my lathe won't do the specified metric threads.....



Started too small on the mating bore for the backplate, but managed to get it threaded to fit eventually.



Backplate fits!




This was supposed to be a "winter project" but I got excited to start!

I have a bronze bearing in the nose and a ground 3/8" rod to use as a datum line to measure off of. Next up is drilling the head hold down holes, transfer passages, and cylinder boring the block. Will brush up on TouchDRO bolt circle then proceed.

 

[Makintrax73]

Ended up making a custom test bar 1/2 thou over 3/8. Used that to get the block tapped in about as close to 90deg as I could get.



Set up the DRO for bolt circles and drilled the transfer ports, and head hold down holes. The main bore I reamed 5/16" for a test bar so I can set it up to bore in the lathe (no boring head for the mill).

 

[Flyinfool]

Looks like fun.

It would be cool to build a engine and then put it on a scratch built plane so everything was DIY.

 

[Makintrax73]

Finally got back to work. Bored the cylinder bore in the block, and copied Blondihacks recent video by making filing buttons for the connecting rod.

 

[Olli-Matti]

Looking good! I was at the same situation as you are about three years ago when I started my first IC engine the Boll Aero 1.8

I wanted to share with you a great article on how to achieve the piston cylinder fits on a model diesel engine incase you are not familiar with it:
https://www.adriansmodelaeroengines.com/catalog/main.php?cat_id=178

Keep up the good work and good luck with the rest of the build. It is a great learning experience for sure.

My Boll Aero build can be seen here:

regards
Olli

 

[Makintrax73]

Looking good! I was at the same situation as you are about three years ago when I started my first IC engine the Boll Aero 1.8

I wanted to share with you a great article on how to achieve the piston cylinder fits on a model diesel engine incase you are not familiar with it:
https://www.adriansmodelaeroengines.com/catalog/main.php?cat_id=178

Keep up the good work and good luck with the rest of the build. It is a great learning experience for sure.

My Boll Aero build can be seen here:

regards
Olli

Thanks, I'll read it for sure. Been saving that for toward the end I heard it is important to get exact!

Worked on turning the crank today. I damn near overshot and had to start over. It about .0005 under what i wanted honestly but doesn't feel loose. Idk we'll see how it goes.

Turning down the shaft to size:



After the other end was trued in a 4 jaw I centered it and used my dro in the mill to drill a center to located the crank pin:



Test fitting parts, checking for clearance:





Next up is the crank pin offset turning. Found out it will require a mandrel. My 4 jaw won't offset far enough on such a small shaft.

 

[Chris Hamel]

Looks good.

 

[Makintrax73]

Mistakes have been made. Lessons learned. Nothing catastrophic as of yet fortunately.





So far everything fits, spins, and doesn't rattle like a jar full of marbles. I'll call it a minor victory

 

[Makintrax73]

Work continues on the cylinder......



View attachment 462540
View attachment 462542
Used a Joe Pie angle plate. Corner located, holes drilled with dro to exact location, then pins used in holes crossways on the top of the vise to skim the 45. This was then used to set the angle to drill the intake passages....


Almost finished...still to cut the top to spec length

 

[Makintrax73]

Looking good! I was at the same situation as you are about three years ago when I started my first IC engine the Boll Aero 1.8

I wanted to share with you a great article on how to achieve the piston cylinder fits on a model diesel engine incase you are not familiar with it:
https://www.adriansmodelaeroengines.com/catalog/main.php?cat_id=178

Keep up the good work and good luck with the rest of the build. It is a great learning experience for sure.

My Boll Aero build can be seen here:

regards
Olli

Olli-Matti, or anyone else that might answer

Now that my cylinder is made (which I made to about .001" under spec to account for lapping) I find that I have about .0006" (6 tenths or .015 mm) of taper from boring it, and it's going the "wrong" way. IOW it is looser at the top than the bottom, instead of tighter at the top. Is that too much to take out with the lap? Should I attempt to turn it around the other way in a 4 jaw chuck and take a very light skim to take some of the taper our? Or just leave it alone and let the lapping process take out that much material.

Thanks.