New Build_Modified David Kersel's Hit and Miss Engine

[Drew]

Hello

I started to get the itch build a small I.C. engine a while back. I have built two Stuart 10H steam mill engines and a free form steam mill type. They are limited due to a lack of boiler and somewhat boring.
I figured it's time to try my hand at an I.C. . After searching, I was 100 percent sure I should build a V8 or at least a V4 . Perhaps in the future. I chose to build a Hit and Miss Engine. A much more viable solution for my current level of involvement.

I began searching for casting kits and plans. After many hours and some limited success, I came across David Kerzel's free engine plans. Perfect! Problem solved. I figured its a little small, but looked like some thing I could just build and not have too much design effort.

While looking at the drawings for a few minutes, I realized there was at least one major thing that needed changing. This was the direction of the angle on his bearing blocks. They are tipped backward away from the cylinder. Putting the pressure of the engine directly on the screws holding the caps. On a model this size it probably doesn't matter except it is opposite of any pictures and encounters I've had of real engines. They are tipped toward the cylinder so that the base casting takes more of the force, not the cap.
Very shortly after, I had started designing an engine based heavily from David Kersel's engine in Fusion 360.
I am still not 100 percent done, but close enough to start making components.

Here are some pictures of what I have so far.

 

[Rudy from Norway]

Very interesting project. From what we can see so far, this will be a runner. Lots of machining on these engines. I`m doing a very similar engine my selves, the Jerry Howel Farm Boy. Keep us posted.

Rudy

 

[Drew]

Today I was able to complete the turning portion of the piston sleeve.
It is a very nice light finger press fit to the cylinder body.
I haven't decided weather to lap or hone the I.D.
made from gray cast iron bar stock.

The original plans call for a cast iron piston and cast iron piston rings.
I was always under the impression that different materials would provide the ideal wear conditions. I'm considering a bronze piston with hard steel rings.
Any thoughts or feedback is appreciated.

Good Night

 

[Drew]

Hello Everyone,
I have been working on the flywheels this week.
Here are some pictures of the non-cam side flywheel.
I made from solid 303 SS .
Ø 4.0 x 0.75

 

[rlukens]

I like your work, especially the way you've radiused corners to simulate castings.
Question: Did you use a rotary table to make the flywheel. If not, I see a lot of setups and tool changes. Great job.[/QUOTE]

 

[Drew]

I have a PM25MV.
It was a manual for two years, then I converted it to cnc.
I built the controller with a BBB and Machinekit.
I am ever improving.
I would like to add a fourth axis.

 

[a41capt]

Nice looking work! I’m following and can’t wait to see the first startup!!!

 

[Drew]

Thanks for the encouragement.

Ive been so busy at work I haven't felt like making much in the evenings.
I have, however, mostly finished modeling it in Fusion 360.
It does not have the carburetor or muffler.

 

[Drew]

Hello ,

Back at it a little this weekend and tonight.
I made the sides and bearing caps.
None of which have been drilled.

Good Night

 

[Drew]

Hello Everyone,
It has been a while since my last post.
I have had some opportunity to work on this project over the holidays.
Here are some photos of what I’ve been up to.
Thanks

 

[Drew]

Hello Everyone,

Finally I am getting around to posting an update.
I am slowly making progress on this build.
The weight arms, weights, and bracket are mounted to the flywheel.
Key ways have been cut in the crankshaft, gear and flywheels.
The valve rocker support is finished.
The valves, guides, and keepers are complete and assembled.
The piston is aluminum with cast iron rings installed. Compression seems good.
I cut the cam into the hub on the gear.

Next the rocker and the cam follower have to be made along with the push rod.
Then I will look at a carburetor and ignition.

Thanks

 

[Johno1958]

Very nice build. Looking forward to see her run.
Cheers
John

 

[John R Pannell]

That is real good Thanks for sharing all the best from John in Texas

 

[Naiveambition]

Very interesting post. I too am building the Kerzel but at 2x scale. I never put thought into the bearing cap direction. I'm sure the larger the engine the more the issue needs addressed.
How did u make the crank?. From solid, press fit? I tried the built up version and while I was able to get it done , the machining was unorthodox at best. And was your crank rod done by cnc?
I will be paying attention to your thread. I am getting into the same area as you are and it's nice to have more reference pics. The plans as I'm sure you know are a little hairy. I've caught myself a few times not looking thoroughly and using the wrong dimension.

 

[Brian Rupnow]

Those are nice looking parts. Good job!!!---Brian

 

[Drew]

Those are nice looking parts. Good job!!!---Brian

Thanks. I want to reach museum quality , but i fear i am very far away.
Dream a little dream.

 

[Drew]

Very interesting post. I too am building the Kerzel but at 2x scale. I never put thought into the bearing cap direction. I'm sure the larger the engine the more the issue needs addressed.
How did u make the crank?. From solid, press fit? I tried the built up version and while I was able to get it done , the machining was unorthodox at best. And was your crank rod done by cnc?
I will be paying attention to your thread. I am getting into the same area as you are and it's nice to have more reference pics. The plans as I'm sure you know are a little hairy. I've caught myself a few times not looking thoroughly and using the wrong dimension.

Hello,
Thanks for interacting with me. LOL
Iv'e been waiting for questions.
I did turn the crank from solid on a manual lathe. It was turned between centers.
I started with a bar of 4140 pre-hard. Cutting it close to length, then squared the ends and brought the length to size in a mill. I mounted it end up and put a flat on the side then center drilled two places.
Then I flipped it over with the flat against the back jaw of my vise. I indicated it in and put two center drilled spots in trier respective locations.
I mounted it between centers in the pre drilled location central with the crank offset.
I turned the crank with cemented carbide, I ground for the purpose at hand.
Then it was mounted on the other set of centers and the far end turned, one at a time.
To turn the main shaft, you have to put a block between the gap where the crank was formed.
Then I milled excess material from the crank to form the weights.
Easy Beans!
I have it assembled now and I need to figure out the carburetor and ignition.
As for the plans, I redesigned it from ground up on Fusion 360.
Using Davids free design as a rough guideline.
I can share with you if you like.
Definitely uncertain about a public release as I have not completed a successful engine.
Regards

 

[Drew]

I have had a number of minor setbacks along the way, but I finally got it to run.
Between valve seating, carburetor issues, and timing problems it took a while to narrow in to get it going.
There is still a lot of details and mounting to take care.

 

[a41capt]

I have had a number of minor setbacks along the way, but I finally got it to run.
Between valve seating, carburetor issues, and timing problems it took a while to narrow in to get it going.
There is still a lot of details and mounting to take care.

Well, we’re waiting with high expectations the release of your video! Let’s see it run man!!!

 

[Brian Rupnow]

About a million people have built David Kerzel's engine. Everybody that built it changed it a little bit. It is a great "building block" for people who want to get into machining their own engines from bar stock. The Kerzel was my second i.c. engine. The Webster was my first. We all owe Mr. Kerzel and Mr. Webster a great big Thank You.---Brian