Anybody have experience with a failed Suburu Head gasket.
  Milo was on the way from Washington to Texas and made it as
  far as SZP. Then the Soob engine had a mysterious over heating
  problem towing a trailer.

  Paul Lamar

  No experience with Soob and blown head gasket, but with a Dodge
Minivan, I  had an overheating problem that seemed 'mysterious'.

  It would overheat, and when you checked the coolant reservoir it
would be  full. When the engine cooled, the reservoir would go down
as expected.

  The problem was a small leak in the head gasket, which would put
  combustion
  gas into the cylinder space, driving the coolant out of the engine
and  into  the overflow reservoir.

  Bill Schertz
  KIS Cruiser #4045
  N343BS

  Bill, did you try any chemical sealants such as duraseal or steel seal?

  Paul Lamar

  Yes I have as that is my business and I rebuild 3 to 4 engines a
week, no  none of those sealants will work as the problem is the
combustion pressure  is pushing past the gaskets into the water
system and pushing the water out  the burp tank and so there is no
way to plug the leak unless you could get  the sealant into the
combustion chamber to shove it into the hole thats  leaking, hate to
say it but you are best to go for a whole engine as you can  mill
the heads when you replace a head gasket but you cannot mill the
block  and the block warps as much or more than the heads so if you
put a new  gasket on a straight head and a warped block it wont last
long, I can do a  compete long block for $1500 to $1600 depending on
which engine it is and I  fix all the problems that Subaru had to
make it better than new.  Give me a call if you need more info.  Ken

  360-834-4089

  I don't know which engine is in that Subaru, but my sister has one
and it  had a bad head gasket and this is a known problem.  They
have an improved  replacement gasket that fixes it but they didn't
do a recall and replace it  on their dime.

  Steve Brazil

  The good news is as far as Milo and family are concerned is they
were able to plug  the leak with goo. After the engine cooled off it
sucked all the coolant back  out of the over flow can. That would
not have happened if the leak still existed.  That is part of the
process. If the exhaust valve and intake valve is closed  hot air in
the cylinder cools off causing a low pressure in the cylinder
drawing  the sealant into the leak. This is somewhat of a crap shoot
as the leak must  occur around the cylinder that happens to stop in
that sealed condition.  Also of course the coolant itself also
contracts drawing coolant in from the  over flow can.

  There has been several recent breakthroughs in these stop leak
type  fluids.  Prior to these breakthroughs most stop leak type
products required you to purge  the engine of antifreeze coolant.
This is no longer true of the better products.  The other
breakthrough is a chemical reaction that is triggered by the high
400 to 500 F metal temperatures that causes the goo to solidify in
the area  of the leak but not in the radiator.

  Here is the web site that claims to be the best.
  It is called Steel Seal. It is a clear liquid with no particulate matter
  at all. It is rather expensive at $70 and they claim to have an
iron clad  patent. "The product is drawn into the damaged area and
seals the crack  with a thermo-chemical bonding process."

  I have not tried it on a leaking rotary yet but
  it sounds promising to fix the shrunk rotor housing problem due to
extreme over  heating of the rotary. Milo has some on order to test
it on the soob if the  stuff we actually used fails.

  https://secure.steelseal.com/index.php/t2b

  Paul Lamar

   The reason the water is pulled back out of the burp tank is that the
coolant system is full of air and it contracts and I still say there
is no stop leak that will plug the leak it is combustion pressure
going going into the water not the water going into the combustion
chamber so you would have to pour the stop leak into the spark plug
hole to get it where you want it, there is no way no how that stop
leak will fix the problem.

  Well while we are on the Subaru subject I may as well make a
confession and I know that is probably a capital sin and I will
probably go to hell for it but I have a 6 cylinder Subaru SVX 3.3
engine sitting on the floor that is going to find its way onto the
engine pylon of my coot.

  Ken

Life is sometimes like that. One takes one step forward and has
doubts and then takes 2 steps back :) What PSRU ratio will you use
with the Soob? You are currently using a 3:1 PSRU ratio with the Rotary.
My guess is you  have about 480 foot pounds at the prop at 6000 RPM
with the rotary.

  231 HP at 5400 RPM  Max torque  228 at 4400 RPM.

Torque times rpm divided by 5252 = HP

So HP times 5252 = torque times RPM

So torque = HP times 52542 divided by RPM

So max soob engine torque is 228foot pounds.

But the max PSRU ratio you can use to keep the prop under
2700 is 2 to one. So torque at the prop is 456 foot pounds.

Running a piston engine at full load max HP RPM is like
standing next to a hand grenade. You need to try it sometime.
A real experience to say the least.
My guess is the life expectancy will be about 300 hours
unless the head gasket goes first or a valve burns :)

Since the last flat six they made was in 1997 you may have problems
finding parts.

The final question is what is the weight. Search as I might but
many say it is heavy. My guess is 3 to 4 hundred pounds while
the rotary weighs 200. The double over head cams and four valves
per cylinder do little for the weight.

IMHO you would be better off with a p-port.

So you save 1 gallon an hour with the Soob for awhile.

Interesting experiment Ken. Keep us informed on how it goes.

Paul Lamar

RE: running a piston.... is like standing beside a hand grenade.
I got that T-shirt. It will fill your shorts when one on the dyno lets go and
you are standing right there. Pieces flying everywhere when a Cat D398 lets
go. Someone put the arm on the governor on the wrong way and when it started
the RPM headed to the high nines. Only supposed to run 1300RPM. When trying to
start a rebuilt engine, you have to bleed the air out of the injector lines.
As you tighten them up as fuel starts squirting out the revs pick up and all
of a sudden you need to take a dive for the end of the engine as 6.25 inch
pistons start vacating the block and imbedding in the block wall. Flames out
the exhaust 5 feet and into the vent hood.

Dale Davies