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Date: Thu, 4 Dec 2008 17:04:15 -0500
From:  <taspilot@cox.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: : First Flight, short and hot
Cc: Jeff Whaley <jwhaley@datacast.com>
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Jeff
Please remove me from your mailing lists.
taspilot@cox.net

---- Jeff Whaley <jwhaley@datacast.com> wrote:=20
Thanks to you all for the congratulatory comments ... attached is a picture=
 of expansion tank and preflight roll-out ... the orange line is fuel retur=
n; the brass is pressure gauge pickup and snifter valve installation.
After reading Eds' email I now know why the water temperature was so high. =
 I installed a thermostat with the onset of cold weather, but I couldn't us=
e the original Mazda thermostat because my temperature bulb protrudes acros=
s the bypass hole.  Originally the bypass hole was plugged and there was no=
 thermostat; however, I removed the bypass plug and used a non-Mazda thermo=
stat !! ... so that's why the underside of the Mazda thermostat is so long!=
 Thanks Ed for setting me straight and based on your comment about 20% loss=
 of efficiency, I could possibly see 230F x 0.8 or as low as 184F on next f=
light ... that would be great! For now the thermostat is gone and bypass is=
 re-plugged.
Closer examination of the belt and rubber deposits on underside of top cowl=
ing suggests the belt got jammed in the pulley and cut by friction.
I tried again last night to remove the alternator pulley nut ... what's the=
 secret? Left-hand thread? Loctite or what? It's so tight I'm afraid of dam=
aging something trying to get it off.
Jeff


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Beh=
alf Of Ed Anderson
Sent: Sunday, November 30, 2008 1:32 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: : First Flight, short and hot

Congratulations, Jeff!!  Safe first flight and that's what really counts, t=
he rest of the stuff you'll get it solved.

On my first flight 13B (No Thermostat - plug the =C2=BD" hole in the bottom=
 of the thermostat housing if you have a 13B - not certain about the Renesi=
s) I had oil temps up to 240F (high as the gauge went).  I don't recall the=
 exact temps on the coolant but I do know they were over my 220F red line.

But, with an outside temp of 32F, I am surprised that the coolant got that =
high and did not come back much when you throttle back.  However, I would s=
ay that the fact that your pressure gauge was that high was a further indic=
ation that the coolant temp problem was real rather than just a gauge or se=
nsor problem.  As other's have suggested, calibrate your sensor and gauges =
 if you have not  already done so.

Another problem may well have been the missing belt.  It is possible that p=
articular if the two belts were not of the same exact length and then you l=
ost one - that the water pump load may have been causing the belt slip and =
your water pump rpm may not have been where it should have been.  Any signs=
 of belt slippage (shiny, hard glaze on the running surface of the belt??).=
  I fly with the dual belt racing beat/MazdaTrix pulley and really like it.

I personally fly without a thermostat - however, it seldom gets and stays t=
hat cold at my airport for any length of time.  Another thing is that if yo=
u are using the 13B (can't speak for the Renesis) with a thermostat - it MU=
ST be a Mazda RX-7  Thermostat OR you MUST plug the =C2=BD" hole in the bot=
tom of the thermostat housing.  If it is not plugged, approx 20% of your co=
olant flow effectiveness is compromised.  IF you have an RX-7 thermostat th=
en it has a feature that plugs the hole when the temps comes up but other t=
hermostats do not.

Lets seem some photos of your cooling ducts and system if you have any avai=
lable.

Again, congratulations on the first flight.


Ed Anderson

Rv-6A N494BW Rotary Powered

Matthews, NC

eanderson@carolina.rr.com

http://www.andersonee.com<http://www.andersonee.com/>

http://members.cox.net/rogersda/rotary/configs.htm#N494BW<http://members.co=
x.net/rogersda/rotary/configs.htm>

http://www.dmack.net/mazda/index.html

________________________________
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Beh=
alf Of Jeff Whaley
Sent: Sunday, November 30, 2008 10:03 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] : First Flight, short and hot

I was in the right seat (flight engineer) when my homebuilt 2+2 made its fi=
rst flight yesterday with the 13B Mazda engine, but not without problems. T=
he coolant temperature reached 230F by circuit altitude; after throttle bac=
k and approach it had only dropped to about 225F; the oil temperature was i=
ndicating only 160F (this could be a mounting-point issue or real I'm not s=
ure ... oil temp measure point is from a small manifold bolted to the PSRU =
mounting plate, with oil flowing from engine to PSRU) outside air temperatu=
re was about 32-33F. The coolant pressure pegged the gauge beyond 20 psi, w=
hich was a surprise as the pressure cap is rated for 20 psi ... I expected =
the engine to burp itself out and maintain 20 psi.

I tightened up the cowling around the radiator and removed the thermostat i=
n an attempt to make a second flight but while removing the thermostat I no=
ticed one of the alternator V-belts was broken ... got another belt only to=
 find it didn't match the other ... these belts really need to be a matched=
-pair. Prior to flight, I noticed the outside belt (which broke) did not ha=
ve the same tension as the inside belt; it must have climbed out of the pul=
ley groove and got sliced by the pulley. Previously I bought a double alter=
nator pulley from Racing Beat but never installed it, due to difficulty wit=
h removing the nut ... thought it best to leave well enough alone ... I wil=
l now put on that new pulley.

Hope to make another flight next weekend if the test pilot is in agreement.
Any comments/experience on thermostat Vs no thermostat?
Why would the pressure cap hold beyond its rating?
Jeff Whaley
C-FJWW