Stewart 51 Partner LLC
June News and Events
The Engine is Pulled in Pensacola
Before, After, and the engine ready to load for the trip to South Carolina for inspection.
Mike Goransky ("Gorilla"), on the right, and me tearing the engine down to pull the left head.  We are removing the intake manifold to allow for removal of the left head for cylinders 2 through 8, to see what is going on with the coolant in cylinder #8.  You can see the rocker cover has been removed for that side.
Al Joniec examines the #8 cylinder.  This cylinder is at the left front of the engine as oriented from the cockpit.  The cylinder walls and top of the piston looked normal.
The left bank exposed.  Number 8 is on the left.
The tan section on the gasket with the piston in the background is direct evidence of a "blown" head gasket, recognized by Robert.  Notice the blue areas of the intact gasket material vs. the darkened areas radiating from the small tan section.
Al, Robert, and Gorilla conclude that, if the heads don't show any cracks in the Zyglo inspection, we don't have any significant damage.  Robert will go ahead and pull and check the pistons, hone the cylinder walls, perhaps add new rings, and put the engine back together.
How did we get to this point?  What happened?

This is the thermostat housing box we began to use about a year ago.  The housing contains two standard automotive thermostats in parallel.  The box was designed with a small hole that allowed coolant from the engine to pass through, thereby giving the thermostats input about coolant temperature, opening to allow greater quantities to flow past to the radiator through the tube exiting the bottom of the box.  In all the testing and experimenting, we never allowed enough coolant to pass by the thermostats, and the coolant had to travel down two feet of hose to reach the box.  Bottom line:  The engine got hot and pressurized before the thermostats ever opened.

 

The cure for this is to run a coolant line from the box section above the thermostats to the water pump, which will allow more total flow from the engine past the thermostats, which will allow them to better respond to changes in coolant (thus, engine) temperature changes.  Cliff Fitch has already gone through the same troubleshooting sequence and has his running just right.

The box viewed from the left side.

Rear view of box.  The temperature probe fitting is shown, mounting in the chamber that houses the thermostat bulbs.

We'll probably be outside of two months before we are flying Doll again, given Robert's schedule, my schedule, and logistics.  In the meantime, we'll be working to get kit parts production amped up.  Will keep you posted.