Kiwi Mk2 Engine
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vcutajar
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Carved up one of the head flanges. I could have left it as is and avoid all the work but something deep down inside convinced me to do it.
First, using the brass template I marked out the head flange (photo 1). Clamped the head in the vice and started milling to the marks (photo 2).
Photo 3 and 4 are showing the flange finished. Now to do the other one.
First, using the brass template I marked out the head flange (photo 1). Clamped the head in the vice and started milling to the marks (photo 2).
Photo 3 and 4 are showing the flange finished. Now to do the other one.
vcutajar
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Yesterday finished the other head flange. It took less than half the time to do the first one.
I think all machining of the head is complete and today after work decided to do a general clean up of the head especially between the fins. These castings are coated with a light grey paint so I thought how about using a paint remover. I tried a small area first and it seemed to be working. So using a small stiff brush I went through all the fins. After a couple of applications of the stripper the paint started coming off with the brush. Washed it under running water and gave it a good clean in the ultrasonic cleaner using water and liquid detergent (photo 2). I think I will use this same method on the crankcase.
I am quiet happy with the result (photo 3). Also the casting defect is less noticeable but still there. I think I am going to leave it as it is, besides, I do not know how to fix it.
Next I will go over the head with fine sand paper to remove the machining marks.
I think all machining of the head is complete and today after work decided to do a general clean up of the head especially between the fins. These castings are coated with a light grey paint so I thought how about using a paint remover. I tried a small area first and it seemed to be working. So using a small stiff brush I went through all the fins. After a couple of applications of the stripper the paint started coming off with the brush. Washed it under running water and gave it a good clean in the ultrasonic cleaner using water and liquid detergent (photo 2). I think I will use this same method on the crankcase.
I am quiet happy with the result (photo 3). Also the casting defect is less noticeable but still there. I think I am going to leave it as it is, besides, I do not know how to fix it.
Next I will go over the head with fine sand paper to remove the machining marks.
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Hi Vince,
Very nice work on the head. It's always the extra work on the details that make the difference. In the course of a long term project the extra few hours spent on the details pay off with an outstanding model.
gbritnell
Very nice work on the head. It's always the extra work on the details that make the difference. In the course of a long term project the extra few hours spent on the details pay off with an outstanding model.
gbritnell
vcutajar
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What I've been dreading since the beginning of this build happened yesterday.
I got that sinking "OMG I've ruined the casting" feeling.
Yesterday I decided to drill and tap the four mounting holes in the top of the cylinder. I used the cylinder head holes as a template and used the usual homemade transfer punch to mark the top of the cylinder. Drilled the first blind hole 7.5mm deep and started tapping 4mm. Started with the tap in the drill chuck and turning it by hand to get it straight then continued by hand with a tap wrench so that I can feel when I reach the bottom of the hole. All of a sudden the tap felt loose in the hole and that's when I got that dreaded feeling. I must have stripped the thread.
After the shock passed I removed carefully the tap and inspecting the hole with a magnifying glass I could still see the thread. Blood started circulating again. I was using the first taper tap. So I continued tapping using the other two taps. Used a 4mm bolt in the hole and it screwed in nicely. So I guess I might have saved the hole. I did not do anything else after that shock.
Today I continued with the other three holes without a hitch.
Used 4mm threaded rod as the studs. Cut the studs in situ with a dremel cutting disk (photo 1) so that they would be of the same height. Photo 2 is the result after the studs were cut and trimmed.
I got that sinking "OMG I've ruined the casting" feeling.
Yesterday I decided to drill and tap the four mounting holes in the top of the cylinder. I used the cylinder head holes as a template and used the usual homemade transfer punch to mark the top of the cylinder. Drilled the first blind hole 7.5mm deep and started tapping 4mm. Started with the tap in the drill chuck and turning it by hand to get it straight then continued by hand with a tap wrench so that I can feel when I reach the bottom of the hole. All of a sudden the tap felt loose in the hole and that's when I got that dreaded feeling. I must have stripped the thread.
After the shock passed I removed carefully the tap and inspecting the hole with a magnifying glass I could still see the thread. Blood started circulating again. I was using the first taper tap. So I continued tapping using the other two taps. Used a 4mm bolt in the hole and it screwed in nicely. So I guess I might have saved the hole. I did not do anything else after that shock.
Today I continued with the other three holes without a hitch.
Used 4mm threaded rod as the studs. Cut the studs in situ with a dremel cutting disk (photo 1) so that they would be of the same height. Photo 2 is the result after the studs were cut and trimmed.
vcutajar
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You can say that again Brian.
Thanks Brian, Arnold and Dave. I think I have 5 items remaining to complete the main items of the engine, two valve guides, two valves and a rocker pillar. Then the ignition, carb and lube reservoir.
Vince
Thanks Brian, Arnold and Dave. I think I have 5 items remaining to complete the main items of the engine, two valve guides, two valves and a rocker pillar. Then the ignition, carb and lube reservoir.
Vince
vcutajar
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Started work on the rocker arm pillar.
Used the piece of 3/8" square stock that came with the kit. Centred it in the 4 jaw chuck with a DTI (photo 1) and turned and tapped one end 6mm fine (photo 2). Then with a thin parting tool I faced the shoulder by trial and error till when it was screwed tight in the cylinder head, one face was parallel to the valve guide holes (photo 3). Then I marked the faces were I need to drill the hole for the rocker arm shafts and calculated how high the hole should be from the bottom of the rocker pillar. Marked where the hole should come. Used a 1-2-3 block to do this (photo 4).
Used the piece of 3/8" square stock that came with the kit. Centred it in the 4 jaw chuck with a DTI (photo 1) and turned and tapped one end 6mm fine (photo 2). Then with a thin parting tool I faced the shoulder by trial and error till when it was screwed tight in the cylinder head, one face was parallel to the valve guide holes (photo 3). Then I marked the faces were I need to drill the hole for the rocker arm shafts and calculated how high the hole should be from the bottom of the rocker pillar. Marked where the hole should come. Used a 1-2-3 block to do this (photo 4).
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