http://www.wired.com/autopia/2009/05/mazda/

 Mark Suspinski

 Nothing new there. I saw it at the 2005 Tokyo Motor show.

 How's the Tracy EFI p-port engine coming?

 Paul Lamar



 What's new in the above is that they delivered it to a customer.


 So we bought a vacuum pump and pulled down a vacuum in the water jacket.
 No
 sooner had we started the vaccuum pump, than coolant started pouring down
 the line and into the pump - lickety split.  After much nashing of teeth,
 we
 drained all the oil out of the pump and filled it with clean oil.  We also
 tried blowing the coolant out of the block by pressurising from the other
 end of the block -- not a drop.  We lifted and dropped the tail.  Not a
 drop.  We hooked up the vaccuum pump, and immediately started drawing
 coolant into the pump again.  Once more from the beginning, draining the
 contaminated oil out of the pump, and trying again to find where the
 coolant
 might be & drain it.  Again, we could not get coolant to come out.  Again,
 we hooked up the pump, and again sucked large quantities of coolant into
 the
 pump.

 After 7 or 8 go-rounds, we stopped getting coolant out every time we
 pulled
 a vaccuum.  We pumped the water jacket down to an indicated vacuum of 24"
 hg.  I used a mechanics stethascope and listened all around the leaking
 PPort.  After quite a while, I found the tiniest of hisses at the
 7-o'clock
 position.  We prepped the area and mixed up some proseal, thinning it to
 the
 consistency of motor oil.  We applied it all around the PPort, focusing on
 the 7 o'clock position.  We did not see any visible sign of anything
 getting
 sucked in.  We finished by applying some thicker proseal all around the
 PPort and left it to sit for 20 minutes with the pump still going.  After
 20
 minutes, we disconnected the pump and left it to cure.

 We'll be going out tomorrow to see if it did any good.  We'll pull a
 vacuum
 again and see if the hissing is still there (can't imagine it will be).
 The
 real test will be when we run the engine again.  After a few cycles of
 heat
 soaking it and letting it cool, (as well as pressurizing the water jacket)
 we shall see if the leak returns.

 I would have felt better about it if I'd seen a little puckering at the
 7'oclock position to indicate something had gotten sucked in.  But perhaps
 that is not to be expected -- what leak there was had to be very small
 indeed to make such a tiny hiss under that much vacuum.

 Mark  (Rocky mtn high)


 I assumed you knew where the coolant drain was on the block :)
 The good news is you were able to pull 24".

 Paul Lamar


 Get thee an air tank - a couple of gallons... Use it as a buffer
 between the engine (which might have coolant) and the pump.  At very
 low pressure (high vacuum), liquid in the system may boil, but I think
 the vacuum pump can move the vapor out without too much trouble.

 I'd install the vacuum gauge in the tank and have two air fittings,
 one near the bottom of the tank (the inlet), and one near the top (the
 outlet - connect to pump), each with a valve.  I'd draw vacuum on the
 tank, shut the pump off, close the outlet valve, and then crack the
 inlet valve, checking for any coolant flow.  The liquid coolant will
 stay in the bottom of the tank (unless it boils).


 Regards,

 Matt-


Yeah, we thought of that.  Lacking a real tank, we cobbled together one by
using a 5-gallon bucket and leak-proof lid.  I drilled and tapped holes in
the lid for 2 fittings.  Hooked it all up and proceeded to draw a vacuum...

It's amazing to watch a 5 gallon bucket 'implode' on itself.  Shortly after
we started pulling the vacuum (and before any coolant started coming out of
the block) the bucket crumpled up like a cheap paper dixie cup.  The seal
around the lid distorted & lost its ability to seal. Thus endeth the
experiment.

It was good for some comic relief, at least ;-)

Mark (Rocky Mtn High)



Bummer.

I'd think the portable air tanks available at auto parts places would
be up to the task..  I see that you can get a 10 gallon tank at Harbor
Freight for $35..  I have a tank used for freon or something similar
that I salvaged for free.


Regards,

Matt-