At The Machine Shop
Byron, the owner of Sports Car Warehouse, a local British auto garage in Arlington, Texas, recommended Arlington Automotive Machine Shop
to have my machining needs met. After discovering that the shop was familiar with my TRactor engine, and was very
near to my favorite pub (a terrific bonus!), I decided it was the one for me.
The first thing I did was leave my crankshaft, block, con rods and head at the shop. All four were "magnafluxed", which
is a process by which metal is checked for stress cracks. After all four were reported as crack-free, I knew
that this engine was worth rebuilding; which in turn loosed a cascade of parts purchases and additional
machine shop work. If these parts did in fact have any cracks, I might have been looking for another engine to rebuild!
Next steps included:
- Block was cleaned, inside and out
- Old camshaft bearings were removed and new ones installed
- Crankshaft pins and journals were measured and found in need of grinding
- Crankshaft was ground to the first undersize dimension of .010", cleaned and polished
- Con rods were cleaned, measured for dimension, trueness and wear and found in good condition
Based on the undersize grinding of the crankshaft, I ordered the engine parts I needed, including the
bearing shells for the rods and mains (hence the need to wait to learn what needed to be done to the crank). I then
gathered up all the rotating components of the engine to have them balanced. These engines, being so small,
and English machining not being the greatest, benefit greatly from balancing. The following parts were balanced
individually so that I can replace a component later, having it balanced individually, and therefore not disrupt the balance of the "system" by adding a new component.
- Pistons are to all have the same weight
- Con rods are to all have the same weight
- Crankshaft should be balanced end-to-end
- Flywheel for rotational balance
- Clutch cover for rotational balance
The last item to be worked on will be the head itself. In addition to cleaning, the following is planned:
- Shave the underside surface to make it perfectly flat
- Remove all old valve assemblies
- Replace exhaust valve seats with stellite seats for super hardness in order to run on unleaded fuel
- Add new valve assemblies
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