Return-Path: Received: from [65.54.241.203] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.2) with ESMTP id 367316 for flyrotary@lancaironline.net; Mon, 16 Aug 2004 15:38:49 -0400 Received-SPF: none receiver=logan.com; client-ip=65.54.241.203; envelope-from=lors01@msn.com Received: from hotmail.com ([65.54.169.54]) by hotmail.com with Microsoft SMTPSVC(5.0.2195.6713); Mon, 16 Aug 2004 12:38:19 -0700 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Mon, 16 Aug 2004 12:38:19 -0700 Received: from 65.54.97.143 by bay3-dav24.bay3.hotmail.com with DAV; Mon, 16 Aug 2004 19:38:18 +0000 X-Originating-IP: [65.54.97.143] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: First flight test report on Renesis Date: Mon, 16 Aug 2004 15:38:16 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_008F_01C483A7.0C836010" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0006.2205 Seal-Send-Time: Mon, 16 Aug 2004 15:38:16 -0400 Message-ID: X-OriginalArrivalTime: 16 Aug 2004 19:38:19.0214 (UTC) FILETIME=[9524EEE0:01C483C8] Return-Path: lors01@msn.com This is a multi-part message in MIME format. ------=_NextPart_000_008F_01C483A7.0C836010 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable The first test created more questions than answers and much work to do. = Here is my development log entry for the flight. Tracy (8-15-04) Flight test report on Renesis engine installation, N84TC =20 OAT 88 - 90 deg Humidity 90+% =20 Pilot impressions: Takeoff done with engine warm (~ 155 F) but water Temp was 207 on first = check after rotation. Reduced throttle and orbited SB for 64 minutes at = ~ 1000 ft. MSL. Engine very smooth with low cockpit noise level. Water = temp slowly fell to 195 - 197 at fuel burn of 5 - 5.5 GPH. Engine RPM = was 4300 - 4700 during flight. Very brief (few seconds) full throttle = test yielded only 5800 rpm and engine did not feel strong. MAP appeared = to be limited to ~ 28" Hg. Water temp immediately climbed to ~ 205 and = power was reduced. Oil pressure continued to read 100 PSI (full scale = on instrument) as it has during ground tests. Engine builder used 3rd = gen rear pressure regulator and it has been my assumption that this was = normal for it. Reset oil pressure high limit on engine monitor to 102 = PSI to get rid of flashing alarm. Oil temps were stable at 185F during = entire flight. Normal landing with engine temps falling rapidly during = final approach. =20 Post flight engine check (engine still hot): Gear drive had normal system lash Turning over engine w/ prop, engine felt tight, higher friction than = previous checks. =20 Rotor compression felt normal (very good) but feel was hampered by = engine friction. Smell test through cooling inlets: Aroma was very different than = earlier engine installation although no sign of anything bad. =20 =20 Significant data: Air temp delta on right side rad was 80 - 85 deg F Water temp delta: 20 - 25 F Oil temp delta: ~ 30 F Oil cooler air temp delta was ~ 45 - 50 F which was normal at the low = power setting being tested. MAP at WOT appeared to be 1.5 - 2.0 " below atmospheric. Analysis: High coolant temperature was very disappointing as I had = expected much better cooling with the improved diffusers. Reasons for = the high temps can be surmised by delta temps above. The high air temp = Delta would indicate one of two things: =20 1. higher coolant temps indicating more heat rejection, or 2. Lower airflow through rad. =20 The coolant temp was higher but only marginally (10 deg after stabilized = at 195) This would not account for a 30+ deg increase in air delta. = This leads me to believe that reduced airflow is the cause. The = diffuser on this rad cannot possibly (?) be worse than before so my = guess is that the greatly extended duct divider that separates the oil = cooler duct from the rad duct is having an adverse effect. Oil cooling = was not a problem and delta was in normal range so it was not hurt by = the divider and may even have been improved. =20 =20 The water temp delta would indicate that the water flow rate is less = than half of the previous value when deltas were in the range of 10 - 12 = F. Two possible causes come to mind. =20 1. The coolant manifolds I made are too restrictive. 2. The water pump design is less effective than the 2nd gen engine. =20 1 was a concern even while I was building them. I thought they would be = adequate because the coolant outlet arrangement does not appear to be = any more restrictive than the previous setup. OTOH, the inlet setup = could be significantly worse than before. It has 90 degree fittings = which could be a problem. =20 The water pump design is the same as the 3rd gen 13B which looks crude = by comparison to the 2nd gen but has evidently been adequate in the auto = racing environment. It may require a much cleaner coolant path in order = to achieve adequate circulation. Or conversely, the 2nd gen pump may be = much more tolerant of restrictive coolant paths. =20 Oil Pressure The 100 (+?) psi oil pressure is a concern after learning from the = engine builder that the 3rd gen oil pressure regulator (presumably = equipped with a Renesis regulator spring) is supposed to give pressure = in the range of 70 - 85 psi. This would indicate that the pressure is = being regulated not by the rear regulator but the front pressure relief = regulator which does not become active until 150+ psi. As I write = this, I decided to check the Racing Beat Tech manual for info on oil = pressure. According to their chart, the 93 -95 rear pressure regulator = is set at 110 PSI !. This leaves me with no firm conclusion about the = oil pressure readings. =20 Engine builder later confirmed that he had pressure spec wrong. 3rd gen = is specified as 110 psi. A 3rd gen car racer also said that his oil = pressure runs 85 - 95 psi hot. Off scale when cold. Have canceled = tentative plans to pull the engine for this problem. I would still = prefer to have a lower pressure regulator and will do this if I have = another opportunity. =20 Low MAP This problem is probably due to the relatively long and tortuous path = between the NACA inlet and throttle body. There is over 4 feet of 2.75" = Dia. Aeroduct (SCEET?) between the two. I was concerned from the start = that this stuff would cause a pressure drop. It will have to go. Many = more hours of fiberglass work required to fix. =20 Did prop pull-through test of engine 'feel' and it was same as earlier = tests prior to flight test. Compression of engine when pulled through = in reverse is impressive.=20 =20 Confirmed that the air temp sensor behind right rad was accurate. In = view of this I have decided to cut the duct divider back to near its = original position and re-test. =20 ------=_NextPart_000_008F_01C483A7.0C836010 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

The first test created more questions than = answers=20 and much work to do.  Here is my development log entry for the=20 flight.

 

Tracy

 

(8-15-04)

Flight test report on Renesis engine = installation,=20 N84TC   =

OAT 88 =96 90 deg

Humidity 90+%

 

Pilot impressions:

Takeoff  done with engine warm (~ 155 F) = but water=20 Temp was 207 on first check after rotation.  Reduced throttle and orbited = SB for 64=20 minutes at ~ 1000 ft. MSL.  Engine=20 very smooth with low cockpit noise level.  Water temp slowly fell to 195 = =96 197 at=20 fuel burn of 5 =96 5.5 GPH.  = Engine=20 RPM was 4300 =96 4700 during flight. =20 Very brief (few seconds) full throttle test yielded = only 5800=20 rpm and engine did not feel strong.  MAP appeared to be limited to ~ = 28=94 Hg.=20 Water temp immediately climbed to ~ 205 and power was reduced.  Oil pressure continued to read = 100 PSI=20 (full scale on instrument) as it has during ground tests.  Engine builder used = 3rd gen=20 rear pressure regulator and it has been my assumption that this was = normal for=20 it. Reset oil pressure high limit on engine monitor to 102 PSI to get = rid of=20 flashing alarm.  Oil temps = were=20 stable at 185F during entire flight. =20 Normal landing with engine temps falling rapidly during final=20 approach.

 

Post flight engine check (engine still=20 hot):

Gear drive had normal system=20 lash

Turning over engine w/ prop, engine felt = tight,=20 higher friction than previous checks. =20

Rotor compression felt normal (very good) = but feel=20 was hampered by engine friction.

Smell test through cooling inlets:  Aroma was very different than = earlier=20 engine installation although no sign of anything bad. 

 

Significant data:

Air temp delta on right side rad was 80 =96 = 85 deg=20 F

Water temp delta:  20 =96 25 = F

Oil temp delta:   ~ 30 = F

Oil cooler air temp delta was ~ 45 - 50 F = which was=20 normal at the low power setting being tested.

MAP at WOT appeared to be 1.5 =96 2.0 =93 = below=20 atmospheric.

Analysis: =20 High coolant temperature was very disappointing as I had expected = much=20 better cooling with the improved diffusers.   Reasons for the high = temps can be=20 surmised by delta temps above.  = The=20 high air temp Delta would indicate one of two = things:

 

1. =20 higher coolant temps indicating more heat rejection,=20 or

2.  = Lower=20 airflow through rad.

 

The coolant temp was higher but only = marginally (10=20 deg after stabilized at 195)  = This=20 would not account for a 30+ deg increase in air delta.  This leads me to believe that = reduced=20 airflow is the cause.   = The=20 diffuser on this rad cannot possibly (?) be worse than before so my = guess is=20 that the greatly extended duct divider that separates the oil cooler = duct from=20 the rad duct is having an adverse effect. =20 Oil cooling was not a problem and delta was in normal range so it = was not=20 hurt by the divider and may even have been improved. 

 

The water temp delta would indicate that = the water=20 flow rate is less than half of the previous value when deltas were in = the range=20 of 10 =96 12 F.   Two = possible=20 causes come to mind.

 

1.  = The=20 coolant manifolds I made are too restrictive.

2.  = The=20 water pump design is less effective than the 2nd gen=20 engine.

 

1 was a concern even while I was building = them.  I thought they would be = adequate because=20 the coolant outlet arrangement does not appear to be any more = restrictive than=20 the previous setup.  = OTOH,  the inlet setup could be = significantly=20 worse than before.  It has = 90 degree=20 fittings which could be a problem.

 

The water pump design is the same as the=20 3rd gen 13B which looks crude by comparison to the = 2nd gen=20 but has evidently been adequate in the auto racing environment.  It may require a much cleaner = coolant=20 path in order to achieve adequate circulation.  Or conversely, the = 2nd gen=20 pump may be much more tolerant of restrictive coolant=20 paths.

 

Oil Pressure

The 100 (+?) psi oil pressure is a concern = after=20 learning from the engine builder that the 3rd gen oil = pressure=20 regulator (presumably equipped with a Renesis regulator spring)  is supposed to give pressure in = the range=20 of 70 =96 85 psi.  This = would indicate=20 that the pressure is being regulated not by the rear regulator but the = front=20 pressure relief regulator which does not become active until 150+ psi. =    As I write this, I = decided to=20 check the Racing Beat Tech manual for info on oil pressure.  According to their chart, the = 93 -95=20 rear pressure regulator is set at 110 PSI !.  This leaves me with no firm = conclusion=20 about the oil pressure readings.  =20

Engine builder later confirmed that he had = pressure=20 spec wrong.  = 3rd gen is=20 specified as 110 psi.  A=20 3rd gen car racer also said that his oil pressure runs 85 =96 = 95 psi=20 hot.  Off scale when = cold.  Have canceled tentative plans = to pull=20 the engine for this problem.  = I=20 would still prefer to have a lower pressure regulator and will do this = if I have=20 another opportunity.

 

Low MAP

This problem is probably due to the = relatively long=20 and tortuous path between the NACA inlet and throttle body.  There is over 4 feet of = 2.75=94 Dia.=20 Aeroduct (SCEET?) between the two. =20 I was concerned from the start that this stuff would cause a = pressure=20 drop.  It will have to = go.  Many more hours of fiberglass = work=20 required to fix.

 

Did prop pull-through test of engine = =91feel=92 and it=20 was same as earlier tests prior to flight test.  Compression of engine when = pulled=20 through in reverse is impressive.

 

Confirmed that the air temp sensor behind = right rad=20 was accurate.  In view of = this I=20 have decided to cut the duct divider back to near its original position = and=20 re-test. =20

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