We are still trying to figure why exactly all the coolant came out. The best hypothesis is an airlock developed in the system and forced the coolant out.

That still leaves us wondering why the airlock started in the first place.

Once piece of the puzzle has been figured out, which sadly creates a new question. The bottle failed due to exhaust heat. We were seeing EGTs close to the yellow\warning zone before the failure. The portion of the bottle that melted was…

Some good news:

First the cylinder bodies were all fine. They measured in spec and had no scaring and no signs of warping.

The better news is the cylinder and heads all passed their hardness tests. The minimum hardness of the heads is 85HB and the Cylinders 90HB.

The heads measured between 102-134 and the cylinders 108-118. The lowest values were for #1 head and #2 cylinder.

As expected the bolts were all loose from the…