Kiwi Mk2 Engine

[metalmad]

Those oilers look just the ticket Buddy
She is really coming along
Pete

 

[idahoan]

Great progress Vince,

Thanks for the updates.

Dave

 

[ProdEng]

Vince, you are nearly there! I can tell you are really looking forward to starting the carb, a project in its' own

 

[vcutajar]

Thanks guys for the kind comments. I'll keep slogging at it until it is finished and yes Jan I am really looking forward to do the carb .

Vince

 

[vcutajar]

Some more progress on the reservoir. First checked if after 24 hours the reservoir leaked. Not a drop in sight which augurs well.

I took a commercial 5mm brass nut and holding in a piece to 5mm BMS threaded at one end, I machined it as seen in photo 1.

Next started work on the dust cover. With a piece of 20mm brass stock, I turned it down to 19mm and knurled it (photo 2). I then drilled a 6.5 mm hole so that the nut I previously made will fit in it. Then using an 18mm endmill I plunge cut the face to a depth of 1.5mm (photo 3). Parted it off and cleaned it up and fitted it to the top of the reservoir (photo 4).

I still need to drill a hole through the dust cover and the top end cap so that the reservoir can be filled and once filled the dust cover is turned to cover the fill hole.

 

[vcutajar]

Started work on the 90 degree oil outlet connection and used a piece of scrap brass (photo 1) to carve it out. Brought it down to a rectangular 8 x 10.5 x 16mm. Ideally I would have used a 4 jaw chuck for the machining but the thing is so small and fiddly to set up in the 4 jaw chuck that I decided to use the rotary table on the milling machine. I first did the nipple on which the plastic pipe will fit. Drilled 1.5mm and then shaped the nipple with an endmill (photo 2). Rounded off the top of the nipple with a Dremel grinding stone (photo 3) and cut 3 grooves with a Dremel cutoff disk (photo 4). Photo 5 showing the nipple finished.

 

[vcutajar]

This evening gave the oil outlet connection another push and managed to finish it. Drilled and tapped 5mm and then drilled a 1mm hole to break through the other 1.5mm hole. Then milled round to a diameter of 6.5mm (photo 1).

Photo 2 is showing the finished connection and photo 3 is the oil reservoir with the current finished parts. I still need to do the needle valve and the knob.

 

[rhitee93]

Great attention to detail Vince

 

[vcutajar]

Thanks Brian.

Vince

 

[vcutajar]

Finally finished the oil reservoir. I made the knob for the needle valve (photo 1). For the needle valve I am actually going to use a needle. It is long and 1.2mm diameter (photo 2). It's not a sewing needle but used for other things. I am sure it has a specific name in English but do not know what it is. I sweated the top part of the needle with soft solder and then soft soldered it to the knob and cleaned up the excess needle sticking out of the knob (photo 3).

Drilled the oil holes and air holes 1.5mm through the centre tube (photo 4). Assembled the reservoir and filled with water to check for leaks and also the operation of the needle valve (photo 5). Seems everything is working as it should but I will leave 24 hours with water to make sure.

Now I need to make a bracket or something for the reservoir.

 

[vcutajar]

Haven't done anything these last couple of days. Today I cobbled up a simple bracket for the oil reservoir. Note to myself : distance between fixing holes is 10mm.

 

[vcutajar]

I had planned for this weekend that I get myself an ignition coil and condensor and hook them up to the timing bracket and sparkplug and see if I could produce a spark. Well nothing of this actually happened.

Instead I decided to make a d-bit which I intend to use on the carb to form the venturi. John (Bogstandard) had made a good article on making d-bits some time ago. Unfortunately only the text remains of that article as the photos are gone. So I made it from memory. I made it from 8mm silver steel and hardened only. It worked out well and a trial cut on a piece of brass worked well. The following photos show the manufacture of the d-bit and the trial cut.

Now I need to make a small boring tool from 6mm HSS.

 

[vcutajar]

This evening I made the 6mm boring tool. Haven't tested it but I suspect it will do a fine job.

 

[ProdEng]

I enjoy making small tools, you get exactly the size and shape you need rather than the compromise of something ready made.

 

[vcutajar]

Well Jan, this week I should start work on the carb. Wish me luck.

Vince

 

[ProdEng]

Good luck Vince When making little bits I always use a magnifier, it's difficult to machine it if you can't see it. Sherline sell a microscope for their lathe and mill but I don't need one just yet.

 

[vcutajar]

Yes Jan, I have that habit of using a magnifier for everything that I do. Infact I would feel lost with out it.

Vince

 

[vcutajar]

Well this morning I finally started work on the carb casting. I have been playing around with it for the last two months and I just could not put it off any longer. I have been making mental notes regarding work holding and casting dimensions (which are all over the place).

So started work on making the hole for the throttle body. I clamped the casting by the small boss on the other side of the body and drilled from 5mm to 10mm in 1mm increments and then first using an 11mm and then a 12mm slot drill finished the hole (photo 1). This should be 12.7mm according to the plans but left it ar 12mm due to not enough material on the casting. I could have gone to 12.5mm but did not want to risk it.

Then using the boring tool I made yesterday I faced off the bottom of this hole. I also faced off the top of the hole with the same tool (photo 2). As you can see it is a bit off centre. Using a thin parting off tool I removed the excess material so that the hole will not look skewed (photo 3). I then drilled and reamed 5mm the hole through the boss. I did not do it before so as not to weaken the boss.

Photo 4 & 5 is the progress so far.

Now I need to do the throttle body. Ideally I should make it in bronze but do not have the required material for it. So I either have to go out and buy some phosphor bronze or do it in brass. Haven't decided yet.

 

[vcutajar]

Managed to get some phosphor bronze for the throttle body. I needed 16mm diameter but could only find 22mm. What a waste.

First drilled and tapped 3mm and then formed the spigot (photo 1). Then turned the throttle body (photo 2). I then used this partial throttle body as a mandrel for the carb body (photo 3). Cleaned up the other side of the carb body but at the end I had to remove the 3mm bolt holding the carb body to the mandrel. I used nylon tie wraps to hold the body to the mandrel (photo 4) and faced off the seat of the bolt. Photo 5 is the progress so far.

 

[rhitee93]

Clever to use the part as a mandrel. I'm not sure I would have thought of that Thm: