Didn’t do a huge amount today….just did a couple of things in between other tasks during the day.
First thing today was to find a container large enough to hold the crankshaft. I managed to find one at Masters Hardware which was only just big enough. I set the crank up on a couple of wooden blocks to hold it off the bottom of the container and filled it up with Simple Green and water mixed approx 4:1.
Next I decided I should start thinking about some of the other items for the engine. I opened up the oil filter and removed the cartridge. There was black slime at the bottom of the filter cannister. When I started to dig it out, it was grey underneath, just like the sump however it was actually dry and crumbly at the bottom!
I cleaned out as much as I could and then set it up in a vice with some Simple Green and water so it can do its magic.
Next job was to have a look at the engine stand. As you may have read previously, the stand has way too much flex. After mulling it over for a couple of days, I decided to reinforce it rather than get another one. The seller offered me a replacement however I know it would have the same problem. I bought a length of 70×45 pine and added a compression member to support the upright, securing it to each of the forward running legs.
It made a huge difference, with all of the flex eliminated. When you move it around it doesn’t bounce like it is going to break either. I drilled a hole before cutting the lower right angle rebate to try and ensure a split doesn’t develop over time.
The only other I did was to blow a quick coat of primer over the inner wheel arch liners in preparation for some black paint.
The 8 Piston Shuffle!
Yesterday evening I re-measured the cylinders using a proper bore gauge. So much easier to use than an inside micrometer, and more consistent.
After I had the sizes, I calculated the piston to bore clearances (measured perpendicular to the crank centreline).
The piston to bore clearance varies from .002″ to .007″ (.005″ range) at the top of the bore and 002″ to .0075 (.0055″ range) at the bottom.
I did some manipulation in a spreadsheet and came up with the following clearances by swapping pistons around:
|Cylinder (perpendicular)||Piston (perpendicular to pin)|
I moved piston 2 into cylinder 1, piston 4 into cylinder 2 etc. You can now see that the piston to bore clearance ranges from .0032″ to .006″ (.0028″ range) at the top and .001″ to .005 (.004″ range) at the bottom.
The range of variation is reduced, which should make the engine more balanced with regards to clearance (and friction).
I weighed the piston & rod assemblies and found that they vary by up to 8 grams. Once the pistons are swapped over I will rebalance the assemblies using my 1 gram scales.