Monday, February 29, 2016

Deck height and shims etc

Just "had" to measure all the deck heights and head volumes for all cylinders. All the head volumes were somewhere between 68 and 69 cc (68.5 on average). I used two head gaskets to measure the deck height + a feeler gauge. The deck height was then 3 mm minus the feeler gauge. Since the piston protrudes, this measure becomes negative.


On cylinders 1 and 2 the deck height, dh, became -2.75 mm and -2.65 mm on cylinders 3 and 4. By using two 0.06 inch shims I will get a CR of:

CR, cylinders 1-2 : 7.78:1
CR, cylinders 3-4 : 7.72:1

The shims coming with the kit are 0.04, 0.06 and 0.09. This will give 0.04, 0.06, 0.08, 0.09, 0.10, 0.12, 0.13 and so on. But, it does not give 0.11. With one 0.04 and one 0.06 I will get:

CR, cylinders 1-2 : 8.07:1
CR, cylinders 3-4 : 8.01:1

This is above 8:1, so I ordered some shims from CB Performance (0.01 and 0.02 just in case). A 0.09 and a 0.02 gives 0.11, and this will be a CR of:

CR, cylinders 1-2 : 7.92:1
CR, cylinders 3-4 : 7.86:1

The I (re) checked the rings, on both ends of the cylinders this time as shown in the new Aerovee DVD.




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