My almost finished first ic engine.

[Johno1958]

It's a Karl.
About 8 months in the making for me so far due to many problems with the lathe , :wall: really bought a lemon there but it is now running well . Just the muffler and wiring to do.Still trying to figure out how to machine the muffler it's a domed type.
Cheers
John

 

[Picko]

That's really well presented John, very nice.

 

[Johno1958]

Thanks Picko.
It came in kit form . Basically everything you need to complete the engine. Castings for the base and fly wheels which need machining and some cnc cut parts and all the bar stock but I had to buy more (newbie) but I learn t a lot about how the hit and miss works and working to tolerance and drawings. Hopefully I can get it to run .
Cheers
John

 

[Brian Rupnow]

Lovely job there Johno--Good luck.---Brian

 

[mattty]

Hi John , great looking engine. what kit is it? and where would I order one from.

Thanks Matt

 

[Johno1958]

G'day Matt
It's a Bengs Karl https://www.google.com.au/url?sa=t&...&prev=search&usg=AOvVaw0vnKT0GG4IOZx0AboktYSJ
This is the translated link which I hope has shown up. It seems to have gone up a bit in price since I bought mine, not cheap but if your careful everything is there down to the coil ,condenser ,points and wire.
Cheers
John

 

[Rudy from Norway]

Like your engine John. I'm building a similar engine my selves (Farm Boy). Like these Hit'n miss engines. Would be nice to see more detail pics. Also a video when it's running. I also would like to hear if you experience something I (and others) could learn from doing an IC engine for the first time. I really struggled to make the valves (I will put a write up on that in my building thread).
Rudy

 

[gbritnell]

Very nice job on the engine. What are you not sure of on machining the domed muffler?
gbritnell

 

[Johno1958]

Hi Rudy.
Thank you. It is a nice looking engine with all that brass. I'm sorry that I didn't do a build log but for months I couldn't make one part without the lathe stopping starting shuddering or dropping speed .I really got frustrated but a new motor and control card it's all better now and I'll have to get a better camera.
The engine is very much fabricated . The crankcase is cnc cut and bolted together. The crank shaft is made up of brass and silver steel which is soft soldered and pinned and I have heard of one that failed with this method.The valves are made of stainless steel. I used 303 stainless which I already had not what they supplied ( unknown grade ) and I machined about 10mm at time along the length. The shaft is 3mm with a head of 10mm and they are 40mm long.If you go to the Bengs site there is a construction report with pictures.
Cheers
John

 

[Johno1958]

Hi Gbritnell.
I am really trying to figure out how to hold it . I do have a sieg radius turning tool to do the dome but I might get some practice up with it first.
Thank you
John

 

[Cogsy]

If it's just the cosmetic dome you are struggling with, a simple (but non precise) way of doing it is to use a plunging type tool (parting off tool is what I use) to take stepped cuts and basically cut a 'staircase' form of the profile. Then carefully file it under power to round it off, sand and polish. If you do some sums beforehand you can work out the depths of cut for each step and the horizontal spacing, so you should end up with a reasonably close approximation. However, normally I just eyeball it if it's not critical and it turns out ok.

 

[Rudy from Norway]

John, I suppose that crank shaft building method is dependent upon how tight the webs and shaft is fitted. If there is room here and this is filled with soft solder, I guess it could fail. I did it with very tight fit, no clearance, LockTite 603 and pinning. Time will show if it holds, but I have confidence. At least the crank is spinning freely with 0.02mm bearing clearance. I also learned (From Brians excellent "tutorial") to make the valves good. I took 5mm at the time. Managed to control the diameter to 0.01mm.
As for the dome I would not hesitate to do it free hand. Make a template and test as you go. Finish of the outside with a file? Maybe hammer it out from copper over a ball? I'll have to figure out the same thing for my own engine.

Rudy

 

[Johno1958]

Thanks all.
Hopefully next week I'll try to start it.
Cheers
John

 

[werowance]

Hi Gbritnell.
I am really trying to figure out how to hold it . I do have a sieg radius turning tool to do the dome but I might get some practice up with it first.
Thank you
John

I did the front cover on my boiler free hand with the dials on the lathe and got it close, then flat file and sand paper with the lathe running and I think it turned out ok. it was a chunk of cast aluminum left over from my failed attempts at home metal casting. and muffin pan ingot is what I cut it out of.

 

[Johno1958]

Werowance that does look nice. Can't wait to have a go my self now.

I couldn't help myself .I have wired it up and gave it a shot of (start ya *******) in the carby and tank and it started and ran for about 10 seconds. Not very loud without a muffler. but that's the end of it today I instantly broke the flexi coupler I was using to turn it over but thats what you get for being in a hurry / lazy so tomorrow I'll make one and get some two stroke fuel and have another go.
At the moment very happy to see some action.
Cheers
John

 

[Johno1958]

Here's the first sustained run I have been able to do using two stroke fuel. It didn't
long to go but the needle on the venturi is all the way closed so either the spring is too long or I'll have to polish the end a little bit but "Phew" it's a goer.
Sorry about the video I'm really not set up for this .
off to play with it a bit more.
Cheers
John
[ame]https://www.youtube.com/watch?v=QbIFDJn8oTc&feature=youtu.be[/ame]

 

[Johno1958]

And the hubs on the flywheels have come loose, that's that ringing scraping
noise

 

[Johno1958]

Just finished the muffler.
I machined the inside of the dome first then parted to length turned it around and supa glued it back to the bar stock and completed the flange and dome. There is a problem when it runs it's like a miss but it "knocks". I thought it might be play in one of the bearings or con rod but I cant distinguish any movement .Might this be a timing spark issue. I have it set to as close as I can get to top dead center where they recommend .
Cheers
John

[ame]https://www.youtube.com/watch?v=buANoEWCATQ[/ame]

 

[Brian Rupnow]

The knock is most generally caused by one of the flywheels having come loose from the crankshaft.

 

[Johno1958]

Thanks Brian that did solve a lot of the knocking . Both flywheels are nice and tight now and it runs better.I'll start trying to get the hit and miss going soon.
Cheers
John
https://youtu.be/lzYldbfE6ak