Hi there! Long time, I know! But, time spent with the nose to the sandstone...errr...grindstone. Phew...that was a LOT of tricky nooks and crannies to sand and blend in smoothly. Worked on Christmas eve too...and will keep at it even today, applying finish coats.
Things which caused delays - biggest one was a modification which will allow *left side shift* with the newer 5 speed transmission. I had never seen one of those transmissions up close until I saw Chumma's. Discovered that the left side shift lever is mounted on a shaft that runs through a hole drilled right through the crankcase. This ofcourse needed a new boss to be accurately located and placed right where this drilling would be. Don't ask me how annoying that was and how long it took :-( Then there was a change in the timing cover for machining reasons, had to completely remove and rethink the bosses for the oil feed banjo bolts. Better now in wood than later in metal. Some of the features of the new design:
1. V angle is now 59 deg. This was arrived at after considering feedback on the original Musket engine, making it more compact, reducing length and making frame fitment much easier while allowing both 350 and 500 top ends. The original 70deg. angle was tricky to fit in the frame. The narrower angle looks nicer, though this is a matter of taste.
2. The oil filter is now housed in the timing cover- the smaller and lower of the two holes visible. This needed a lot of relocation of the internals but simplified the oil circuit (the original motor has an external filter housing which needed more plumbing). The larger and upper hole, at the 'peak' of the timing cover is the ignition/points housing, which is now a part of the casting, as opposed to the bolted on housing in the original engine.
3. Cooling fins sculpted onto the timing cover. Just HAD to do this :-) Pretty! The timing cover is much more in keeping with classic air-cooled aesthetics. It is overall a much more sculpted, smoothly radiused form which recalls fondly the beautiful castings from our favorite vintage engines. Took a LONG time!
4. New motor will allow left side shift with the 5 speed gearbox.
All in all, I think this is an improvement. Let's see how it goes.
Forgive the *slight blurriness* of some photos, after so much sanding, my hands are just a bit shaky :-)
Don't miss the very last photo which shows the two complete sets of identical twins :-). Yup, everything had to be done twice over to make a backup pattern. After the disaster last time....
Things which caused delays - biggest one was a modification which will allow *left side shift* with the newer 5 speed transmission. I had never seen one of those transmissions up close until I saw Chumma's. Discovered that the left side shift lever is mounted on a shaft that runs through a hole drilled right through the crankcase. This ofcourse needed a new boss to be accurately located and placed right where this drilling would be. Don't ask me how annoying that was and how long it took :-( Then there was a change in the timing cover for machining reasons, had to completely remove and rethink the bosses for the oil feed banjo bolts. Better now in wood than later in metal. Some of the features of the new design:
1. V angle is now 59 deg. This was arrived at after considering feedback on the original Musket engine, making it more compact, reducing length and making frame fitment much easier while allowing both 350 and 500 top ends. The original 70deg. angle was tricky to fit in the frame. The narrower angle looks nicer, though this is a matter of taste.
2. The oil filter is now housed in the timing cover- the smaller and lower of the two holes visible. This needed a lot of relocation of the internals but simplified the oil circuit (the original motor has an external filter housing which needed more plumbing). The larger and upper hole, at the 'peak' of the timing cover is the ignition/points housing, which is now a part of the casting, as opposed to the bolted on housing in the original engine.
3. Cooling fins sculpted onto the timing cover. Just HAD to do this :-) Pretty! The timing cover is much more in keeping with classic air-cooled aesthetics. It is overall a much more sculpted, smoothly radiused form which recalls fondly the beautiful castings from our favorite vintage engines. Took a LONG time!
4. New motor will allow left side shift with the 5 speed gearbox.
All in all, I think this is an improvement. Let's see how it goes.
Forgive the *slight blurriness* of some photos, after so much sanding, my hands are just a bit shaky :-)
Don't miss the very last photo which shows the two complete sets of identical twins :-). Yup, everything had to be done twice over to make a backup pattern. After the disaster last time....
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