Anderson Ed wrote:

Paul wrote:

Paul Yaw wrote:

Hey Ed,

You make a good point in your message, and I agree that the internet is
full of "unproven facts."  I do not have an opinion as to what gets
posted on the website, but I do have an opinion about plugs up.  Chris
Ross and I have this argument at least once a month.  I admit that I
have no way to prove this, but I feel that running plugs up is a bad
idea.  In looking at the oil drain situation, I cannot guess what exact
problems may be caused, because I cannot watch the oil flow with the
engine running.  As for the water, I REALLY dislike the idea of having
the hottest point of the water jacket at the top of the engine.  This is
a problem area even with the engine mounted conventionally.  As I said
before, I cannot prove my assertions, but as an engine builder, I am not
comfortable with the idea of supplying an engine that will be run plugs
up.

I have spent a great deal of time trying to decrease the metal
temperatures in this area, and I still feel that there is room for
improvement.  I have considered adding some clear vent/recirculation
tubes to the plug area of the water jacket to see if there is any steam
in there.  I am worried about steam pockets in a conventionally mounted
engine!  It seems that the only way to accurately assess the situation
is to run two engines for the same amount of time, at the same power
level with both configurations, and then disassemble and inspect them.
I do not see this happening anytime soon.

Smokey Yunick modified a Chevy cylinder head years ago by attaching a
piece of plexiglass so that he could see the water flowing through the
passages.  What he found was a whole bunch of steam pockets.  Obviously
it is not fair to say that "If the Chevy did it, the Mazda does too."
but it is food for thought.

Until I can prove to myself that running plugs up is OK, I would not
recommend it.  I would rather take that approach, than to wait for
someone to prove that it is a bad idea by shipping a prematurely worn
engine back to me.

Like I mentioned before, this is just an opinion, and I am extra
conservative when it comes to engine longevity.

Good luck with your project.

Paul Yaw

Hi Paul,

 Well, I am certainly no expert on the 13B and as I have stated before,
I certainly do not advocate "Plugs Up".  On the other hand, I don't
think there is evidence (yet) to indicate it is necessarily a flawed
approach.  From your perspective, I can certainly understand
conservatism when you are building engines for $$ paying customers.  Too
bad, we can't get a grant from NASA for a few hundred K $ to explore
developing the 13B for aircraft applications and have folks like
yourself do various tests{:>}.

 Your point about potential steam pockets are certainly valid, but on
the other hand as you point out, we simply do not know for certain
whether there may be long term adverse effects from running "Plugs Up".
It is simply educated spectulation at this point and while it may be
valid, then again only emprical evidence will provide the proof of the
pudding and that is what we will hopefully gain from those of us trying
"Plugs Up".

  As best, I can tell, I am the only one to encounter problems that may
be attributed to "Plugs Up" (or at least have revealed them on this
list).  The two problems that come to mind are the need (at least in my
case) to fully "burp" the engine when completely replacing the coolant
to remove air and the oil foaming problem I had from providing only one
vent to the block and having selected the one vent that vents the
central housing where the rotors dump their cooling oil.
Both of those "problems" are now resolved.

In any case, I certainly value your assessment of the potential problems
that may be encountered from this approach. Thanks again.

Ed Anderson

I would not claim your problems are "resolved" Ed if I were you untill
you 
have accumulated hundreads of hours as some of the upright AC engines
have.
Furthermore there are thousands of upright car racing rotary engines out
there as well with decades of experience. 

A glance as this picture will inform anyone that the oil will drain
better
and the oil chamber will vent better when the engine is upright.

cutaway2.jpg

Paul Lamar


 
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