Kiwi Mk2 Engine

[idahoan]

Hi Vince

I'm not exactly sure why it might not work but it sure looks nice!

Dave

 

[vcutajar]

Thanks Dave.

When I deviate from plans there is always that nagging feeling that it might not work. My reasoning of changing the float chamber into a fuel tank is that if the Kiwi worked with fuel just coming from a plastic pipe then why shouldn't it work with this method. Still keeping my fingers crossed.

Vince

 

[jack620]

That's an amazing first effort. Well done!

 

[Lawijt]

If it don't work......You can make a fuell tank like Jan Ridders. He takes the fumes from the fuell. So it will never been too rich. I know all about engines & the fuell...But I'am not able to build it. Now I build a flame eater from Jan , but it is a lot of trial & error. But I learnd somethinges right now , zeroing the mill. That helps me a lot.

Barry

 

[vcutajar]

Nice one Barry. Keep it up. I am also still learning things. The trick is to jump in and give it a try with something easy and do not worry if you make mistakes. We all do them.

Vince

 

[vcutajar]

I made a dummy fuel inlet nipple (photo 1) which will screw into the bottom of the tank. This will make it look like the real float chamber.

I had some spare time and started looking at the exhaust pipe. The few photos I managed to find on the internet of the Kiwi all had a short straight exhaust pipe. I thought why not make a longer pipe with a 90 deg bend? Truth be told, I have never bent brass pipe, only copper. I took out my miniature pipe bender and tried to make the bend.

Well, you guessed it, total failure (photo 2). Tried again but this time very slowly. Still no joy. Actually even worse (photo 3). Blaming the pipe bender, I tried a 10mm copper pipe (did not have 8mm) and it made a very nice bend. Maybe brass pipe is not meant to be bent. So, the exhaust pipe has to be straight unless I use copper pipe but for some reason copper pipe for the exhaust did not look good on the Kiwi.

 

[Charles Lamont]

I should think the brass tube would need annealing, perhaps several times during the bend.

 

[vcutajar]

Thanks Charles. Good idea. I'll give it a try.

Vince

 

[joe d]

Vince:

I can tell you from personal experience that Charles has nailed it.

I do have several spare bits of tubing that look just like yours if you need more
crumpled up brass.... from before I learned this.

If you have access to some, filling the tube with some cerro-bend will give an even nicer result when combined with annealing.

I've been enjoying following along on your build, thanks for bringing us all along!

Cheers, Joe

 

[Lawijt]

When I have to bend a tube.......
-close 1 side
-fill it to the top with table salt & shake a bit
-close the top than
-bend it
-open the tube & let the salt coming out

Than you have a beautifull bend.

Barry

 

[camm-1]

I used chromed copperpipes for my Hoglet, these plumbers use for bathrooms etc.
Ove
You can by It hard or soft, the soft bends very nice.
Ove

 

[vcutajar]

Thanks Joe, Barry and Ove for your suggestions. Joe, wish I could find cerro-bend here.

Success, sort of.

Me, not resisting a challenge, decided to try again the bend. I followed Charles suggestion and annealed the brass. I annealed, bent, annealed and bent. Photo 1 shows the result. I was getting a flat area on the outside radius. Did not like it. So I redid it and bent a little less between annealing operations. Photo 2 showing the result. Not perfect but I can live with that.

Having finished that, I turned my attention back to the fuel tank. Screwed in the dummy fuel inlet in the bottom of the tank and used a locknut, I had made extra when doing the carb banjo, to lock it (photo 3). Photo 4 is how it looks from inside the tank. I tapped a 3mm hole so that I will screw in a lenght of 3mm threaded rod which will eventually hold the fuel tank cap.

Just noticed that this is page 52 of my build log. Hope I did not overdo it and bore everyone to death. If so, apologies from my side.

 

[idahoan]

Hi Vince

I'm not bored; still enjoying your progress, quality work and great updates.

Thanks,
Dave

 

[Gedeon Spilett]

If I follow properly, your aim is to replace the float chamber by a plain fuel tank, in this case it looks rather small for a 15 CC, beautiful but small, really smart with the carb in bronze.
The tank also will become pretty hot so close of the engine.
Cheers

 

[vcutajar]

Gedeon

Yes, I agree with you, the tank will be rather small. I estimate that there will be enough fuel for a 2 minute run. I usually do not run it more than a minute because the cylinder and cylinder head gets very hot and I do not want to damage it. Does yours also get very hot?

Dave

As you are not bored, here is another update.

Yesterday I silver soldered the exhaust pipe to the flange and pickled it in white vinegar. Today I cleaned it up (photo 1) and fitted it to the cylinder head (photo 2). Gave the engine a run and it gives a nice motorcyle noise with the exhaust pipe.

I was thinking of maybe giving the crankcase only a lick of engine paint. Maybe a very darkish grey, nearly black. What do you guys think? Or should I leave it as is?

 

[Generatorgus]

Vince, coming along nicely. Making the "smalls' after you get it running are a lot of fun, even if you crinkle a pipe or two.

Paint, I vote for the dark grey.

GUS

 

[Lawijt]

Please , do NOT paint that beautifull motor.

 

[Gedeon Spilett]

I vote for no paint at large, just a few part tinted, maybe, blued screws & nuts, a touch of black inside the flywheel, but take care that yours engine does not look like a steam engine !
Yes My engine is pretty hot, as long as the engine runs on the bench, how can we avoid it ? I get burns by the exhaust pipe while tuning, I put a fan now to cool things a little bit.
cheers

 

[vcutajar]

Oh well Gedeon, I am making sure I do not give my engine a hard time. I run it nearly daily for just a minute and it seems to run better each time. To start on the first attempt I open up the throttle to half and the needle valve 1.5 turns. As soon as it starts I throttle it back to idle.

Today I finished off the wooden base by drilling the mounting holes and giving it two coats of teak oil.

Also today I finally started work on the fuel tank lid. I did not start it earlier because I was still working out how to machine both sides. The lid is only 4mm thick. Started off by machining the top part of the lid (photo 1). I left a longish spigot on purpose so that I can use it to hold it in the chuck when machining the other side. With the parting tool I removed some excess material on the side before parting off (photo 2).

Turned it over and holding it by the spigot I machined the bottom of the lid (photo 3). Now all that remains is drilling a 3mm hole through the spigot and milling off the excess spigot. I also need to drill a vent hole in the lid.

 

[vcutajar]

Fuel tank finished but have not tested it yet.

Finished off the lid by drilling the 3mm hole through the boss and then milled off the excess boss material. Then drilled a 1mm vent hole (photo 1).

Then manufactured a small brass knob (photo 2) to hold the lid in place. Final photo is the tank bolted to the carb banjo. It looks exactly like the original float chamber except for the brass knob at the top of the lid.