Kiwi Mk2 Engine

[vcutajar]

Cleaned up the sides of the cylinder head. Used the centre mark I left on the top of the head as my datum. I first did one side and then the other side.

 

[steamer]

That head is looking awesome Vince. That would seem not that far away..... I'm watching!
:bow: :bow:
Dave

 

[vcutajar]

Thanks Dave. Still a lot of work to be done on the head. I think you will finish your Southbend before I finish my Kiwi. ;D

Vince

 

[steamer]

Rof}

Ah a race to the finish! at blistering pace !

:

Don't worry Vince.....we"ll both get there!
:bow:

Dave

 

[idahoan]

Vince

The Kiwi is really starting to take shape now; the head looks nice sitting on the engine. I like the way you fixtured it in the lathe to machine the combustion chamber and related surfaces.

Keep up the great work.

Dave

 

[vcutajar]

Not much done the last couple of days. The temperature here is starting to build up (30 deg. C) and had to switch on the fan in the shop. That also means that the silly ..........oops.........busy season has started at work. Progress will be relatively slower.

Made another fixture for the cylinder head. Similar to the previous round one, but this is rectangular (photo 1). I drilled and counterbored the holes around the centre mark (barely visible) of the rectangle. Now I need to buy some allen head bolts for this fixture. The ones I have are either too short or too long. Maybe tommorrow after work.

I also changed the 4mm tapped holes in the head to 4mm clearance holes. I screwed in the 4mm tap in the threaded hole clamped the tap in the drill chuck and clamped the head to the mill table. This to align the spindle to the tapped hole (photo 2).

 

[vcutajar]

A little progress on the cylinder head. With the head bolted in the rectangular fixture, I clamped it in the vise and using the centre mark I left on the head and the DRO I marked the holes for the valve guides and the rocker arm pillar (photo 1). I also marked for the port holes in the flanges (photo 2).

Drilled and reamed 5mm the valve guide holes and also drilled and tapped 6mm fine the hole for the rocker pillar (photo 3).

Now I need to do the port holes but waiting for a long reach 8mm ball nose cutter.

 

[vcutajar]

Also today I received the 2mm square keysteel (photo 1). It was nicely packed in a black plastic tube.

Cut a piece to size with a dremel. Found out I needed to make the groove in the shaft deeper. Decided to try and make it deeper and if that did not work out I would do a new shaft. Deepening the groove worked and photo 2 shows the cam on the shaft with the key. I noted that for some strange reason, that if I insert the cam in one direction it goes in easily and if I try it from the opposite side it is stiff to slide in. A little persuasion with a plastic hammer was needed.

 

[vcutajar]

Nothing new since my last post.

Today I received the spark plug and tungsten points from Hemingway. I have a couple of questions about the spark plug. What gap should I set in the plug? Also, the spark plug gap, does it have to protrude in the combustion chamber?

I have been thinking about the port flanges and was thinking of doing a brass template to make it easier to mark and machine the head flanges. Then I might then use the brass template as the exhaust flange. The fixing holes for the flanges should be 6BA and for me that's close enough to make them 2.5mm. So this morning I went shopping for a 2.5mm tap set but could only find a machine tap. Got it. Then I went shopping for 2.5mm bolts. Big problem. Can't find them here. There is still one place which might have them but did not have time to check. If I still can't find them then only option is to get them from the UK. They are going to be the most expensive bolts to date.

 

[ShedBoy]

Hi Vince the engine is looking great. I source alot of my small fasteners from thi place

http://stores.ebay.com.au/spalding-nut-and-bolt?_rdc=1

It is cheaper to get them from the UK sent over than it is to buy them here in OZ. Crazy

Brock

 

[vcutajar]

Well the silly season is officially open.

Today I was going to continue the local search for 2.5mm bolts for the flanges. I had decided that if I cannot find 2.5mm I might try for 2mm bolts. Just before going out I had another look at my BA conversion chart and to my surprise I noticed that the outer diameter of 6BA is 2.8mm which is closer to 3mm than 2.5mm. What must have happened is that by mistake I looked at the tapping size for 6BA which is 2.3mm.

During the weekend I received the long reach 8mm ball nose mill (photo 1). So I started work on the port holes. Started with the horizontal holes. Clamped the head in the vise. Centre drilled and drilled 6 and 7.5mm. Then reamed 8mm and then used the new ball nose mill to give it a radius at the bottom of the hole. For all these operations I used a collet holder instead of the drill chuck. Photo 2 showing one of the finished holes.

I also faced off the flanges to the desired size.

 

[vcutajar]

Bolted the head to the rectangular fixture upside down. Located one of the valve holes with a 5mm silver steel in a collet. Clamped the fixture to the mill table (photo 1). Drilled 7.5mm and the reamed 8mm (photo 2). Using the new 8mm ball nose radiused the bottom to match the other horizontal hole (photo 3).

For the valve seat I used a countersink tool (photo 4).

Next time I will do the other hole.

 

[vcutajar]

Slow progress but at least some progress.

Finished the other hole and valve seat (photo 1).

Also started work on the flange template made out of brass (photo 2).

 

[steamer]

That looks great from here Vince! Nice finish on the head and ports.

Dave

 

[vcutajar]

Thanks Dave.

Finished the flange template (photo 1) and might actually use it as the exhaust flange. All I need to do is silver solder a short piece of brass pipe to it. We'll see.

Photo 2 is depicting the brass flange just held in place to the head. Now I need to drill and tap 3mm the head flanges.

Also, if you look close enough, there is an imperfection in the head casting. There is a depression in the casting (just behind the cylinder head flange) which will not affect the operation of the engine but is starting to bother me aesthetically. Is there any way I can fix it? Like filling it in with something and then file it off. The head is going to be left bare metal (aluminium). Is there something which approximates the colour of aluminium which can be used as a filler?

 

[vcutajar]

Phew, it's hot here. Been +35 deg C for the last three days and they are saying it might go up to 40 tomorrow. And we just started summer. Not very conducive to do anything except sitting down in a cool spot.

Today I managed to do the spark plug hole.

Set the head up in the vice at 60 deg (photo 1). With this setup I can see where the drill is coming out in the combustion chamber. I did not follow Westbury's method because I could not picture it and it involved trial and error. Milled flat the spark plug face (photo 2). Picked up the centre of the head from the mark I had left and marked the line on the freshly milled face (photo 3). Did not find a way to mark the other line to get the centre of the hole. So I put a 14mm endmill in the chuck and eyeballed it. Drilled the hole in steps of 1mm all the time checking the bottom of the head. At 7mm decided to move the x axis 0.1mm to one side and used an 8mm slot drill to continue. Drilled 9mm and then tapped 10 x 1mm. Did not go right through with the taps.

 

[vcutajar]

Some photos of the spark plug in the head. I removed the washer that comes with the spark plug so that it could go in deeper. Figured that the plug tightened on soft aluminium will be a good seal. We'll see.

I hope that the spark plug gap is protruding enough in the combustion chamber?

 

[metalmad]

looking good Buddy :bow:
Pete

 

[steamer]

Looking good Vince.....your getting close now!

Dave

 

[vcutajar]

Thanks Pete and Dave for the encouragement. I needed that.

Vince