"Brian D. Cain" wrote:
Nope, Paul. That's one of my street-ported 4-port motors. On that
particular engine, since we're aiming for high-end power, I brought the
port outlet up about 8mm and re-shaded the edges. It does kind-of
look like what a 6-port might look like after going nuts with a die
grinder
for 20 minutes, but that's just a street-ported secondary intake port.
Nothing fancy; I learned alot of the theory behind how I do my ports
from
all you guys here on the list over the years. :) That picture there
was
taken after disassembly prior to me cutting eyebrow bridgeports in the
secondary intake ports.
Considering the 5th and 6th port sleeve inserts on the 6-port motors,
I'm
not
honestly sure how I would port those. Since the engine would starve
down
low for torque, I doubt I'd cut the iron bridge out that divides the two
on
the
front and rear iron housings. Rather, I would just sand down port
tunnel
walls,
re-shape and even up the port outlets (on the side housing facing), and
taper
and round-out edges to help make the charge swirl and spin into the
compression
chamber better.
By the way, while we're on the subject, check out the picture of the TES
o-ring
that came out of that engine. The teflon jacket was torn in one area
near
the
hotside (near the leading plug area) and created an internal water leak
into
the
front combustion chamber. I think the teflon jacketting was beat up due
to
severe
engine knock although I'm not sure. The other reason for rebuilding
this
was to
replace those TES inner water jacket o-rings. Boy, those things are
stout.
B
Brian D. Cain -/- Grand Prairie, TX -/- bdc196@attbi.com
MSN bdc196@hotmail.com, Yahoo! bdc196, AOL Symajhi, ICQ# 1733105
http://bdc.genxracing.com -/-
http://groups.yahoo.com/group/HaltechSupport
Looks like it was pinched on installation. Can you send it to me?
If it is detonation perhaps a small protective slot machined both
in the rotor housing and the end housing with a thin SS shield would
protect
the O-ring. Labeled as "SPECIAL SEAL" in this drawing.
Also what brand TES was used? McMaster Carr or Creavey?
Were the apex seals fractured? You did not mention it so
I assumed that did not happen. What apex seals did you use in this
engine? Looks like this was a Garett TO4 turbo engine. Correct?
What HP do you think it was generating? You guys really know
how to test things quickly :)
Paul
"Brian D. Cain" wrote:
The seal might have been pinched during installation. It was the inner
water
o-ring for the centre iron housing on the front combustion chamber. I did
have
that iron housing off three times while I was assembling his engine just
prior
to the fault, but I remember seeing a slight "nick" or distortion in the
teflon
jacketting of that o-ring during installation and (then making a bad
judgment
call) ignoring it, thinking it wouldn't be a problem. I did wind up
pinching
an outer stock o-ring in the very same place during assembly (one of the
two reasons we were pulling it apart again).
The brand of TES o-ring used for the inner water jacket o-ring was
Mc-Master Carr. I haven't purchased any of the Creavy stuff yet but most
definitely will on the next engine I use (and more than just these o-rings).
His engine was running perfectly until he got overzealous one night and
decided to show one of the new guys here what it felt like. He wound up
running 23psi of manifold pressure (don't ask me why) on pump-station
fuel and hot spark plugs. I think the mixture auto-ignited from the
volatility
of pump fuel over anything else. It happened somewhere prior to the
trailing
spark plug area. It shattered two apex seals and damaged the rotor and the
housing very badly. It left three "Devil's Claws" in the rotor housing and
somewhere around 20-30psi on all faces in that front combustion chamber.
The rotor housing was barely 3000 miles old and now it's junk. I only
assume the TES water jacket o-ring I had in there wound up taking some
force of that engine knock. I could be incorrect on this.
The engine is a series 5 (89 through 91) engine block with stock rotors,
stock 2mm 3-piece apex seals (the Mazda ones), and an 80/85psi oil
pressure regulator setup. The turbo he's using is either a TO4E 57trim
or a TO4E 60trim and that's guessing from the casting of the compressor
housing as well as looking at his power output curves juxtaposed against
those two compressor maps. The vehicle made about 370hp to the
wheels on a dynamometer, running right around 15psi of manifold pressure
at just over 7000rpm, without tuning prior to us taking it back apart again.
B
Thanks for the great report Brian. We learn more from our failures.
Any plans to use two piece or 3 mm apex seals in the rebuild?
Paul Lamar
The AirCraft Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/
Copyright 1998-2002 All world wide rights reserved.