# Atkinson Cycle Engine Supersized



## Tom T (Nov 13, 2007)

I have started a new project and thought I would share it with you. I am building a large Akinson Cycle Engine to power a small ride on tractor.

What I have is a flywheel that I am going to build a engine to fit . :roll: I have the frame all most done and will post pictures when I get it further along. Here is a picture of the flywheel it was a raw casting . I hade to grind the spur off of the outer rim to get it to fit in the lathe.The flywheel is 18" dia. 57 lbs.          Is this a model it is being built from bar stock?
            Tom


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## Bogstandard (Nov 14, 2007)

Tom,
Of course it is a model, just a little bigger than normal.
I like your logic by the way, it's like "I found this tail light, I will build a car to go around it", great way of thinking.
Love to see it as it progresses, keep us posted.

John


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## 1Kenny (Nov 15, 2007)

Tom,

That looks like the one on the tractor picture in my book. Page 41.

The book I have is called; The Agricultural Tractor 1855-1950 by R.B. Gray.

Kenny


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## Tom T (Nov 15, 2007)

Kenny I ran and got my book thinking you solved the flywheel mystery what was it made for. Thats the picture I used to build the model tractor.  your right its close   Tom


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## 1Kenny (Nov 16, 2007)

Tom,
 After looking at it in your lathe (several times), it sure looks like the exact flywheel on page 67 top right corner showing the oscillating magneto. But I can't figure out what engine its on. Does it have those casting marks like the ones on the spokes in the picture?

Kenny


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## Tom T (Nov 17, 2007)

Kenny the engine looks a lot like a 8-16 mogul. the first ones had a sheet metal water hoper. and they only had one flywheel. my flywheel has no casting marks .I think thats where the belt pulley bolts on. I will post more picures on this project soon.  Tom


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## Tom T (Nov 18, 2007)

This is picture of the crank bearing holes being bored.  After the bosses where welded on they needed rebored for good alignment. I first bored one end and made a dowel pin with threaded hole in the end to fit a T nut.  I installed the dowel pin and indicated it in. Slid the bored end over it and bored the other end. This worked out good This is a trick I learned from the Henry ford plans. sorry about the bad picture






This picture shows how I cut the keyway. By advancing the tool and cranking the carriage back and forth what seemed like a hundred times.






This is a picture of it tack welded together for a trial fit. I  know it needs more bracing and some bling  :lol:


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## Tom T (Dec 7, 2007)

I made a little progress on this project. The cylinder bore needs finished, its a little rough. I bored it in the lathe with a 12" boring bar. The bore is 11" deep by 3.75 bore. Its to big for the mill. How would you clean it up? It needs about .150 taken out of it. The boring bar is not rigid enough.

I really like the new site. You guys did a great job. Thanks to all who made it. 
          Tom


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## Bogstandard (Dec 7, 2007)

Goodness me Tom, that is starting to look rather impressive.

That is a long way to have the boring bar sticking out, no wonder it isn't rigid enough.

There are only two ways I can suggest, the first is to make a more rigid bar, use 1.5" diameter if need be (you have enough diameter spare in the bore), weld a square bar on the side to hold it in your toolpost. You can always recycle it afterwards for making other bits.

The other is to mount the job on the cross slide and use a boring bar between centres, but that would require some very careful shimming and setting up. This would give you the same sort of action as if you were boring it on the miller.

Maybe some of the big machine or production guys can come up with an easier answer for you.

Best of luck with that one.

John


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## 1Kenny (Dec 7, 2007)

That is looking real good Tom.

A larger dia. bar is all I can think of too. 

Kenny


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## Tom T (Dec 30, 2007)

Thanks for the post Bogstanderd and Kenny. I mounted a bearing on the ends of the cylinder and bored it out with a portable boring bar 
 Here are some pictures of the carb. cylinder head,rocker arms,pushrods,cam.
  enjoy Tom T


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## Powder keg (Dec 30, 2007)

Looking good Tom! How does a portable boring bar work? Never seen one of those.

Wes


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## 1Kenny (Dec 31, 2007)

That is really taking shape, Tom. I love the way you did the inner and outer rocker arm shafts.

Kenny


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## deere_x475guy (Dec 31, 2007)

Tom your engine looks like it is coming along real well. Can't wait to see that big guy run..)


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## zeusrekning (Dec 31, 2007)

That looks awesome. My personal interest is in large "model" IC engines. I haven't built any yet but I'm working on it. You definitely work quick. Is it difficult to make a functional carb? I haven't been able to find any good info on building one online.
Looking forward to seeing some videos of that one running by the end of the week


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## cfellows (Dec 31, 2007)

Heck of project, Tom. Happy to see you aren't letting up!

I'm studying your Carb pictures, since I have an upcoming task to build one for my Open Column twin. What is the purpose of the ribbed nipple coming in at an angle beside the needle valve adjustment screw? It appears to me that the brass tube opposite the adjustment screw is the fuel line connection.

Thx...
Chuck


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## Tom T (Dec 31, 2007)

Thanks everyone for your nice comments. 

Kenny, the rocker arm shaft was taken directly from the Atkinson cycle model plans and enlarged. 

zeusrekning, I would like to have it done by the end of the week but big parts take a long time to make and take up a lot of material. 8) I probably could of built 3 or 4 small models in the time it has taken me to build this. But I think it will be worth it. 

cfellows, the ribbed nipple is the fuel line attachment and the brass tube you are seeing is the butterfly shaft [throttle] I pulled the carb of off a old international LB engine that was throttle governed and built this one from looking at it. I don't know yet how well it will work. It has no idle circut. The barbed fitting has a drilled passage that comes in just behind the needle valve. The needle valve is drilled thru to the smallest part of the vintura. 

Powder keg, here is a picture of the bearings mounted to the cyl. The boring bar is slid thru the bearings, and the drive unit is slid over the bar and the outer part of the bearing and clamped. The bar is fed in by turning the all threaded shaft. This is a home made drive unit that I built several years ago. A guy could build a smaller one of these and use it to bore the crank shaft bores on a model engine. You could power it with a slow speed drill and just push it thru.


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## Powder keg (Jan 13, 2008)

Somehow I missed this Tom. How's it coming?

Wes


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## Tom T (Jan 13, 2008)

Hello Wes,
      Here is a little update for you. I boxed in part of the frame and made a gas tank. Built another cam, rocker arm and push rod for the points. Built the exhaust system. Then I completely disassembled it and added gussets and mounts. Welded all the joints. Sanded and primed it. Cut red oak to cover the base. I weighed all the parts and came up with a total of 275 lbs. Maybe it won't jump around to much. ;D

      After seeing all the nice projects on this forum I thought I'd better add a little more detail and bling. When I get it reassembled I will post pictures.         Tom


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## Powder keg (Jan 13, 2008)

Glad to see you are making progress:O) I still don't quite get how that boring thingee you have there works? Maybe you could elaborate on it a bit, please?

Thanks, Wes


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## Tom T (Jan 18, 2008)

hello I made a little progress.I don't no if I like the exhaust.What do you think about it? Wes I will post some more pictures on the boring bar . Tom


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## 1Kenny (Jan 19, 2008)

Man, the engine is looking good Tom. The exhaust looks to be the right size to the valve port. Were you thinking about a shield to make it look fuller up to the bell? Is the tractor under the blankets? ;D

Kenny


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## Brass_Machine (Jan 19, 2008)

Tom

That looks really nice. And my opinion?!? the exhaust is brilliant. Very cool.

Eric


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## Powder keg (Jan 19, 2008)

That is a very classy loking engine you are building there, Tom. I'd try the exhaust and see if You like it. I think it's awesome!


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## Tom T (Jan 19, 2008)

The exhaust Is my second try at it here is the first.What under the blanket? well under one of them is a 1912 stover T hit miss engine I restored last year.under the outher is my old lathe it need cleaning and I dint what you to see that  No tractor yet.





Here is a picture of what under the wood.The wood box is the coil,the brass pipe is the fuel tank fill port,and the battery is to the right.


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## 1Kenny (Jan 19, 2008)

Wow Tom,

I like _that_ exhaust. It looks like it belongs on the engine and matches the style.

Kenny


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## cfellows (Jan 19, 2008)

That's a beauty, Tom. Great work! 

Chuck


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## AllThumbs (Jan 19, 2008)

Nice! Was the exhaust a base ball bat in it's former life?

Eric


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## Tom T (Jan 19, 2008)

Yes it was.I got the ideal from my neighbor he use them on his cushmen scooters.
Tom


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## zeusrekning (Jan 19, 2008)

Tom that looks awesome. I like the alum exhaust. How about a bend, mabey a ninety back toward the flywheel? Again, looks really good.


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## deere_x475guy (Jan 19, 2008)

Tom, it's looking awesome. I agree with kenny that exhaust looks like it belongs on there.


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## Tom T (Jan 19, 2008)

Zue I had it cut at the top at a 45 and recut it strait it just wasn't right maybe a dom on top. I built the carb. linkage and wider up the coil and kill switch.Check the timing.Sprayed a little starting fluid in the carb,turned the switch on and it fired on the forth turn and and ran for five or six turns.

IT WAS AWESOME ;D ;D ;D Tomorrow I will put fuel in the tank and get some video  Tom


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## 1Kenny (Jan 19, 2008)

Tom,

Does it have a fuel pump or will it be a gravity feed for the fuel?

Kenny


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## Tom T (Jan 20, 2008)

I ran the engine today it look like it going to run nice and slow . I still have a little tuning to do on it .Kenny it has no fuel pump just a check valve in the line.Here is the video.My son is cranking it I am adjusting the carb. Tom


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## Powder keg (Jan 20, 2008)

That is super!!! I like the movement of the linkages:O)

Wes


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## Brass_Machine (Jan 20, 2008)

My wife thinks I am a geek.

Saw the video and called out to her "you gotta see this! it is very cool!"

Very cool Tom.

Eric


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## 1Kenny (Jan 20, 2008)

That is great, Tom,

There is a lot of action going on. It is nice to see the smiles on you guys.

Kenny


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## AllThumbs (Jan 20, 2008)

Fantastic.


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## rake60 (Jan 20, 2008)

Very impressive Tom!

Rick


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## Tom T (Feb 24, 2008)

Thanks guys.Here is an up date. I had trouble keeping fuel up to the carb. The engine idles at 125 rpm and did not have enough vacuum.I think Kenny knew this when he posted about a fuel pump.But I missed the hint.In the first video I was holding my hand over the carb. to keep it running.I raised the fuel tank and installed a shutoff valve in the fuel line.It idled better but would not accelerate.I redused the venture and it runs good now.

I built a fan to keep it cool but it need more rpm will have to build a bigger drive pulley.

Here is some more videos.Watch the start up real close.  Tom


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## te_gui (Feb 25, 2008)

Wow, that thing has more action then a hula dancer. So I think you said you were going to drive some kind of a tractor with it. I was just curious of you were going to do that off the walking beam on the back to another flywheel or directly off the existing flywheel?

Very cool


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## Powder keg (Feb 25, 2008)

I love the sound of that engine) Very unique. I can't wait to see the tractor)

Wes


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