Daag44

The piston to deck clearance is also not the actual squish. There is also the dome step to take into account. I do remember you finding none on your domes, but that's still a mystery to me.

Glad to take the coolant testing off the list, but not the cylinder head temp. If someone can give me a hint how to go about rigging a probe to a head bolt, it would be much appreciated.

Now for the coolant problem:

1. Eau désionisée (a new revolutionary product) $5

2. Coolant tank test cap 529 021 400  ~$50
3. Vaccum pump ~$70

4. Coolant tank if warped (or insert) 509 000 409 ~$65

Those warped tanks are such a pain when I can't get them to screw without a pair of pliers to hold them round. Ever wonder what causes the warpage???  I don't really like counting on holding the front end up high to purge the system, and a test cap with vacuum pump works great. The gurgling from the purge is difficult to miss.

A leaky tank is not something I want after spending $$$ on new engine parts. A vacuum test on a cold engine is also not all telling. The coolant tank needs to be solid enough to hold pressure, and if it's warped and passes the good old vacuum test, it's only a guess as to how well it holds the pressure with hot coolant.

 SNC01656 - Coolant tools - DT.jpg   42.8K   0 downloads

Now that the head is torqued, CC won't give a good presentation of the squish, which is really what your after. Of course we all know the head needs to be removed to measure the dome volume, and I was playing with details, but the point is that CC is also relative to the piston. If the CC shows a correct squish, but in fact the dome to piston clearance is too small, then the CC isn't necessarily the all out test.

Even if I were to believe the measurements are inaccurate, I think they deserve more attention, and a CC test will not make those numbers go away.

If you can show a micro picture of the smallest deck to piston clearance measurement, I think that would help sort this out.

Problem with CC method at this point is that it will be completely inaccurate.

What is this thin plate on the water jet?

Actually, Doo have given the measurements for squish height: min 0.031 in, max 0.063 in. Problem is how to get reliable measurements. From the current measurements, the smallest squish is found on the pto outer side (assuming the drawing reflects the position of the bottom end on the other pictures). If those measurements are correct, then the min squish would be 0.025 which is  ~81% of the min tolerance (0.025 / 0.031). This is the type of stuff that I find very interesting.

The doubling-up of base gaskets is something I also find interesting. Not sure if it's a good idea, but it's been done on this engine. Port timing is where things get fuzzy, and I'm not equipped or experienced enough to measure accurately. Just like the squish, easy to measure but difficult to know if it's done right.