Follow along as I build a high performance 914 engine
First Dry Assembly
Now that the case halves are clean:
And I'm happy with the way they fit together:
It's time to do some test assembly and get some measurements.
For this, I'll use my "special engine assembly table" - really it's just a table with a wood top that I've drilled holes in so the head studs can pass through. I used this table for my 944 engine and it worked superbly! Anyhow, here's the #3 / #4 case half on the table:
The new bearings fit nicely on the new crank, and it fits nicely into the case:
Put the other case half in place and tighten the 6 through bolts:
The crank spins as nice as can be! Silky smooth! So, I bolted the flywheel in place, put a dial indicator on it and was able to measure the crank end play (which was 0.047"). There are three shims that go between the flywheel and the thrust bearing (rear most crank bearing) - by getting the right size shims, I can bring the end play into spec.
Next, I put one piston and rod together and put it in the #1 cylinder spot. After sliding a cylinder over it, I was able to use my new homemade tool - a dial indicator mount that I'll use to measure deck height and TDC (top dead center - or the very top of the piston's travel before it starts moving back down):
By turning the flywheel slowly, I can watch the needle on the dial indicator and find the exact top of the piston's travel. (This same tool will be used to measure the deck height (the distance from the top of the piston to the top of the cylinder). It looks like I'll need spacers 0.146" thick between the case and the bottom of the cylinders to achieve a 0.040" deck height.)
It's interesting to note that when the piston is at true TDC, the mark on the flywheel is lined up here: (I assume it should line up with the split between the cases... I will measure TDC for all cylinders to verify the crank was ground properly.)
It is even more interesting to note that the timing mark on the impeller fan is considerably off location - perhaps as much as 5 or 10 degrees! (I will, of course, be putting a new TDC mark on that...)
|All pictures and text copyright 2008|