A compression test will tell you if your engine has good compression. An engine is essentially a self-powered air pump, so it needs good compression to run efficiently and start easily. Good compression is one sign of a healthy motor.
So anyway, both of these motors are a bit on the elderly side, with the Spider somewhere north of 100,000 miles and the 164L at just over 170,000 miles. I wanted to see how the compression was for each cylinder and make sure the compression values were all within 10% of each other.
Well I am happy to report that both motors are showing good compression values for all cylinders! The Spider motor is by design a lower compression motor so it naturally has lower compression values than the 164 engine. This is not bad, just different by design.
Here are a few pics I took. You can see the black engine control unit (computer) in the Spider under the rear parcel shelf. I needed to get at this so I could disconnect the fuse which powers the fuel pump (for testing purposes). Other pictures show both motors with all spark plugs removed and with the compression testing gauge in place (it gets screwed into each spark plug hole, one at a time, test is performed, then on to the next).
Also you can see a picture of one of the rather unique (and pricey) Golden Lodge spark plugs which the Alfa 164L uses. Notice that these plugs have 4 side electrodes instead of the single side electrode commonly found on automotive spark plugs. One nice thing about them is that you never have to adjust the gap between these electrodes and the center electrode. Neato!
Finally, you can see a pic of my scrawlings on a piece of paper as I recorded the compression values for each cylinder on the two motors.
What a fun night! I like "garage time" :=)
1 comment:
The Milton compression tester (a 30 year old fine American made tool) once again proves itself.
Glad the compression numbers were so good.
Post a Comment