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lee webster

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Oct 4, 2019
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Location
Cornwall UK
I have a confession to make. I have started to dismantle my Austin Seven engine so that I can start designing the half size model. (Is it half size or half scale?) Today I wanted to remove the flywheel which is held onto the crankshaft by a taper and large nut. The nut was easy to remove and I have a flywheel puller. It consists of a bar of steel an inch wide by ¾” thick by about 2 ½” long. It has a threaded hole in the middle and 2 holes that line up with 2 blind threaded holes in the flywheel. All threads are ½” BSF. My puller was missing the central bolt. I remembered that the last time I used it to remove a flywheel I had to use a lot of heat, brute force and swearing. It took several days to get that particular flywheel off, and the middle bolt was beyond saving. So, I had a puller, but no very important bolt and ½” BSF isn’t available locally. I found a piece of steel rod about the right diameter, and I had a ½” BSF die. What I didn’t have was the correct die holder. I had bigger and smaller, but not the right size. There was only one thing I could do. Sorry, you might want to cover your ears. With the steel rod clamped in the vice I used a pair of water pump pliers to turn the die. I cut about 1 ½” of (wonky) thread and screwed the puller into the 2 flywheel holes and tightened down my home made bolt. It seemed to be working until I realised that one of the flywheel bolts was pulling out of its thread. The flywheel threaded holes are only about ½” deep at the most. I removed the bolts and cleaned out the holes as much as I could. Re-assembled and tightened I started to hit the middle bolt very hard. Several moments later the flywheel sprung off the taper and I could remove it. I still have the crankshaft to remove, then I can measure the crankcase and produce a 3D drawing before 3D printing it.
 
Thank you. I don't feel so bad now! My progress is very slow. I had to learn how to use a cad programme and once I had a 3D print, to cast that part in aluminium. I started on the small parts first, the top water outlet, and the side water outlet. I am now watching many videos about casting by producing a wax or pewter part to produce a finer detail. I would like to cast the cylinder head next. I think the design is almost done. Lee
 
Thank you. I don't feel so bad now! My progress is very slow. I had to learn how to use a cad programme and once I had a 3D print, to cast that part in aluminium. I started on the small parts first, the top water outlet, and the side water outlet. I am now watching many videos about casting by producing a wax or pewter part to produce a finer detail. I would like to cast the cylinder head next. I think the design is almost done. Lee

This might have saved you some work.....took all of about 1 minute to find.

http://archive.a7ca.org/collections/technical-drawings/
 
I have the two relevant drawings from that list. They were avaiable from an A7 spares outlet. Very useful, as is having an engine to measure up.
 

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