X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2367187 for flyrotary@lancaironline.net; Wed, 03 Oct 2007 19:19:23 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Received: from edward2 ([24.74.103.61]) by cdptpa-omta04.mail.rr.com with SMTP id <20071003231844.EYMS2011.cdptpa-omta04.mail.rr.com@edward2> for ; Wed, 3 Oct 2007 23:18:44 +0000 Message-ID: <001101c80613$c4b412a0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Problem? [FlyRotary] Re: Coolant Water Pressure Date: Wed, 3 Oct 2007 19:18:55 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000E_01C805F2.3D706620" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 This is a multi-part message in MIME format. ------=_NextPart_000_000E_01C805F2.3D706620 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Grass? what grass? {:>) Yes, it sounds like the air should rise to the top of your slanted = radiator. However, My experience has been that unless I run the engine = up to around 5000 rpm for about 15-30 seconds (does not have to be long) = that I do not have much success getting air out of the block. It seems = to take that velocity of coolant flow to drag the water out of the = block. You have over 700 cubic inches of core, so that should be plenty for = cooling a two rotor. =20 A multi pass radiator (two pass in your case) can require more coolant = pump flow as indicated by this extract from a pretty respected name in = racing/cooling circles: Double pass Double pass radiators require 16x more pressure to flow = the same volume of coolant through them, as compared to a single pass = radiator. Triple pass radiators require 64x more pressure to maintain = the same volume. Automotive water pumps are a centrifugal design, not = positive displacement, so with a double pass radiator, the pressure is = doubled and flow is reduced by approximately 33%. Modern radiator = designs, using wide/thin cross sections tubes, seldom benefit from = multiple pass configurations. The decrease in flow caused by multiple = passes offsets any benefits of a high-flow water pump. =20 Again, these are just back of the envelope calculations based on a great = deal of assumption about your parameters. My gut feel is that 700 cubic = inches should have no problem cooling your installation at those power = settings even being a double pass radiator. So I would look else where. You indicate you have an approx. 80F delta T across your radiator core = with the coolant temp a 210F. You have a fan which apparently has the = spec to draw 970 CFI across the 11" dia of the Fan. Lets assume that = was the flow through the entire core. Then that would give you = 970*.0765 =3D 74 lbm/min of air mass. Q =3D 75 * .25 * 80 =3D 1500 BTU/Min just due to the flow resulting from = your fan - it would seem that plus whatever flow you are getting from = your prop - Prop??. =20 Hey, this dumb question just occurred to me - I assume you are = running with a prop?? in a tractor configuration. I lose track of who = has what. Ed ----- Original Message -----=20 From: Bill Bradburry=20 To: Rotary motors in aircraft=20 Sent: Wednesday, October 03, 2007 5:12 PM Subject: [FlyRotary] Re: Problem? [FlyRotary] Re: Coolant Water = Pressure I have an aluminum double pass radiator with the finned core size of = about 18.25 X 18.25 X 2.25. It is behind the engine and leaning = rearward at the top at about a 30-35* angle. The water from the engine = enters on the left lower and crosses the bottom half of the radiator to = the right side then rises and goes back across the top of the radiator = and exits the top left side and returns to the engine. My radiator cap is at the top right corner of the radiator at the = point where the water starts its second pass through the top half. My = pressure port is just below the radiator cap. The pressure sending unit = is in a "T" with the hose which goes to the =BC" port at the top of the = rear iron connected to the other side of the "T". I thought that this = hose could have some effect on the pressure, but I am not certain why it = would. =20 Any air in the system should either rise to the top of the radiator, = or if it was trapped in the block, it could come through the hose to the = radiator. All air should be found therefore? Under the radiator cap. I = have never found any air there. =20 I think I found out a little something about the fuel system today. I = only put a few gallons in the right tank and have been checking for = leaks and running the engine on this fuel. I wanted to run it down to = the "non-usable" level and then do the same thing with the left tank. = So I have been really low on fuel. My pressure has been holding, but I = thought that I could hear bubbles from time to time going through the = lines. =20 Anyway, before, I could get a good start by setting the mixture at = about 4 PM oclock and it would fire up in a couple of blades. Today, I = tried hitting the primer button a couple of times and it would start and = immediately die. I finally had to set the cold start on and leave it on = just to get the engine to run! Finally after it warmed up, it ran with = the mixture set at 12 oclock, but it was not steady. As my fuel ran = out, the pressure dropped finally to about 28 lbs and the engine started = its death rattle. I shut it off at that time. =20 The temperature had risen to 210* the ambient temp was 87-88* and the = air after the radiator was 168* This is with my radiator fan running. = (11" and 970 CFM) probably about 10-12 minutes of running the engine . My oil temp was only 160* and the air temp after the oil cooler was = 145* , I think that this would gone higher if I ran longer, because the = oil in the pan was up to 170-180* or so. The pan holds 5 qts, 8 qts in = the system. Water pressure was up to 22-23 lbs and oil pressure was 70 lbs. =20 All my temp probes are within a degree or so of one another and with a = mercury thermometer in the hangar when reading ambient temp and the = engine is cold. I think they are all correct. =20 I have the air/fuel ratio setup that comes with the EM-2, but it = doesn't work till the O2 sensor gets to about 800* or so, no help on = trying to figure out starting ratio. =20 The timing brings up a good point. I got the Renesis out of a wrecked = car with 1800 miles on it, so the timing is set to the factory setting = for the Renesis. I have never checked it. Does anyone know what the = factory setting would be for the Renesis?? =20 Staging is a good point, but I think that you are correct about having = enough fuel to run a low speeds and not enough to run faster. I was = running out of fuel and probably didn't have enough to rip it. =20 You really have good insights when you are helping folks.. You are = pretty right on with your advice. =20 Thanks, Bill B (Must mow yard.Must mow yard..) -------------------------------------------------------------------------= ----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Ed Anderson Sent: Wednesday, October 03, 2007 12:53 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Problem? [FlyRotary] Re: Coolant Water = Pressure =20 Yes, too hot for that rpm, I agree. =20 Assuming you followed the good suggestions offered by Al, Lynn and = others regarding getting all the air out of the block - really = important! I almost cooked engines two times because of excess air in = the coolant system. Here is something that may quickly tell you = something about the air you may have in the system. =20 I can't recall what type of radiator set up you have, but with the = Two GM cores I use which are mounted vertically, you can touch the side = tank of the radiator and determine if there is air in the system. In my = case, if I do a complete drain and refill of the system, on the first = run up the core's tanks will be hot approx 2/3 of the way up and then = they are much cooler - indicating that the remaining 1/3 of my core is = filled with air. It generally takes me 3 runups reaching 5000 rpm = before I can touch the core tanks and find them hot all the way from = top to bottom. So depending on your radiator set up that might be = something you can quickly check. =20 If the mixture is too lean, you can get a backfire out the intake, too = rich and its generally the exhaust - where unburned fuel cooks off. So = that and black smoke would indicate to me too rich a mixture. I = presume you do not have an Air/Fuel ratio indicator - strongly recommend = you get one, that tells you right away whether you are running rich or = lean. Even a cheap one can be a tremendous help in finding out whether = too rich or too lean. =20 One thing you may want to check is your ignition timing. If using = Tracy's EC2 you need to set the static timing around 35 Deg BTDC. The = EC2 backs off 10 deg from that (25Deb BTDC) as its default starting = point for ignition timing. So if you set the static timing to say 25 = Deg then the EC2 would be having the engine operate at a 25 - 10 deg =3D = 15 Deg BTDC which is pretty retarded timing for the rotary. OR if you = set it too far advanced then the timing might be too advanced. So just recheck it when you get the chance. =20 Another possibility is your injection system might not be staging = properly. IF that were the case, the engine might work fine below the = staging point but not above it. Could possibly be a sticking secondary = injector (if too rich or lean). But, that is a bit down the likely = list. Something impeding the fuel flow might provide sufficient fuel = and low rpm but not sufficient to run at high rpm. =20 Hope some of this helps =20 Ed =20 Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.dmack.net/mazda/index.html =20 =20 =20 =20 =20 =20 ----- Original Message -----=20 From: Bill Bradburry=20 To: Rotary motors in aircraft=20 Sent: Wednesday, October 03, 2007 11:23 AM Subject: [FlyRotary] Re: Problem? [FlyRotary] Re: Coolant Water = Pressure =20 Ed, this is at about 2000 rpm. Like a fast idle. I am getting all = kinds of fuel cut like stoppages if I try to run the engine faster. I = haven't seen more than about 3700 rpm, but I just started it and have = not tried to tune anything. I figure I will have to run longer to get = it tuned and the cooling is holding that back. =20 Speaking of that, you guys were talking a while back about the = effects you see when the engine is too lean, or too rich. Talking about = backfires, etc and what each effect represents. I have forgotten what = means what.senior days, not moments! Do any of you remember how that went? I am having some problems = getting started and am not certain if I am too rich or too lean. I am = getting backfires out the exhaust at times and smoke from the exhaust at = that time. (black) I ran the batteries down yesterday trying to get started due to = this. When I originally started the engine, I flooded it. I am trying = to prevent this now and am concerned that I may not be using enough = mixture. =20 Bill B =20 -------------------------------------------------------------------------= --- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] = On Behalf Of Ed Anderson Sent: Wednesday, October 03, 2007 10:05 AM To: Rotary motors in aircraft Subject: [FlyRotary] Problem? [FlyRotary] Re: Coolant Water Pressure =20 Bill,=20 =20 You indicate you get overheating after 10-15 minutes run time. I = may have missed it, but is this at idle, max throttle or what. Also = what is your OAT. If at idle or low power then, yes what you are seeing = is not what it should be. On the other hand, if at WOT or high power = settings, then 10-15 minutes run time would be indication of a great = cooling capacity. I can not run my engine more than a minute or two at = WOT on a 80F day without temps getting into the 200F range. But, that = is at 5800-6000 rpm. At idle, the temps stabilize and I can idle all = day with safe temps. =20 My coolant system runs with no air cushion and yes, I get a = hydraulic "lock" pressure reading of as high as 25 psi immediately upon = engine start up. After a 30 - 60 seconds of running the pressure drops = down to zero and then after a few minutes running builds back up as the = coolant warms up to operating temperatures. =20 =20 Plenty of suggestion have been made about what to check - all good. = =20 Good luck. =20 Ed =20 Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.dmack.net/mazda/index.html ----- Original Message -----=20 From: Al Wick=20 To: Rotary motors in aircraft=20 Sent: Wednesday, October 03, 2007 9:30 AM Subject: [FlyRotary] Re: Coolant Water Pressure =20 Bill, the definitive test is the one I described below. Really = encourage you to do it as described. Resist assumptions. Convert your = ideas to measurements. =20 -al wick ----- Original Message -----=20 From: Bill Bradburry=20 To: Rotary motors in aircraft=20 Sent: Wednesday, October 03, 2007 6:08 AM Subject: [FlyRotary] Re: Coolant Water Pressure =20 I think that I would see air under the radiator cap if I had a = compression gas leak? I never see any air.=20 To check a piston engine for head gasket leaks, you would put = the cylinder at TDC and pressurize the cylinder to about 150 lbs with = compressed air and check the radiator for air bubbles.How do you check a = rotary? I will check the pressure sender against a mechanical gage. =20 There is obviously a heating problem, but I think the pressure = is higher than it should be until just ready to boil. I shut the engine = off at 210*, and at 22+ lbs, the boiling point should be well above = 250*?? =20 Thanks for the suggestions of where to look, guys. =20 Bill B =20 ------------------------------------------------------------------------ From: Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On Behalf Of Al p Wick Sent: Tuesday, October 02, 2007 7:49 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Coolant Water Pressure =20 Your coolant reservoir should be above engine.=20 =20 1) If it is, remove two cups of air from the reservoir. Then = repeat your test.=20 2) If you now see pressure rise above 22 psi within 5 minutes of = cold start, you clearly have compression gases leaking into cooling = system or bad gage. =20 3) Air in the block is 10 times more significant than any other = cooling factor. Make darn sure you don't have any. It causes local = boiling, high temps, strange behavior. =20 Operating with two cups of air under cap is an important safety = and diagnosis advantage. Everyone should do it. With that two cups, you = only see 22 psi if you have a genuine problem. You only see 0 psi if you = have genuine problem. The pressure is then a very fast and reliable = indicator of system integrity. So two cups of air has no negative effect = on system efficiency, just a substantial improvement in safety. Only = time it could be a negative would be if your reservoir was way too = small, way too low, or flowed way too much coolant. =20 Since you describe high temps AND pressure, I suspect you have = temperature problem. =20 I deliberately overheated my engine many times so that I was = intimate with pressure and temperature patterns. Then tested various = concepts. Don't recommend you do the same. =20 -al wick =20 =20 On Tue, 2 Oct 2007 12:38:55 -0400 "Bill Bradburry" = writes: I just recently got my Renesis started again after finishing = my cowl. I seem to be getting very high coolant pressures. I can only = run the engine about 10-15 minutes before hitting the redline at 210*. = My water pressure is at 27 Lbs at that time. I only have a 22 Lb = radiator cap, so I assume that I am blowing into the recovery tank, but = I have not confirmed that. My oil temp has never exceeded about 165*. = It might have gone higher if I could have run longer??? =20 This whole water pressure thing has me a little baffled. = Since this is a closed system and the only way pressure can build is due = to the expansion of the coolant after heating???, I am confused by some = comments that have been made from time to time. I remember something = that Tracy said about his pressure would build for a time, then go to = zero. It seems to me that the pressure should correlate to the temp = pretty closely since it is a closed system??=20 =20 Can someone enlighten me a little on the science of this = pressure? It seems to me that there could be some pressure build up on = the positive side of the pump, but it would go negative on the suction = side, so the net effect of the pump should be close to zero?? =20 Also, my Renesis had only 1800 miles on it when I bought it, = so I did not have to tear it down. As a result, I am somewhat in the = dark as to how the water flows through the system. Could someone help = me with that? I had to remove the thermostat tower for height clearance = , so I made an adapter plate that takes water from the top outlet of the = pump and sends it to the radiator (double pass), then from the radiator, = it returns to the lower inlet of the pump. =20 Thanks, Bill B =20 -al wick Cozy IV powered by Turbo Subaru 3.0R with variable valve lift = and cam timing.=20 Artificial intelligence in cockpit, N9032U 240+ hours from = Portland, Oregon Glass panel design, Subaru install, Prop construct, Risk = assessment info: http://www.maddyhome.com/canardpages/pages/alwick/index.html -Al Wick Cozy IV powered by Turbo Subaru 3.0R with variable valve lift and = cam timing.=20 Artificial intelligence in cockpit, N9032U 240+ hours from = Portland, Oregon Glass panel design, Subaru install, Prop construct, Risk = assessment info: http://www.maddyhome.com/canardpages/pages/alwick/index.html ------=_NextPart_000_000E_01C805F2.3D706620 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Grass?  what grass? {:>)
 
Yes, it sounds like the air should rise to the = top of your=20 slanted radiator.  However, My experience has been that unless I = run the=20 engine up to around 5000 rpm for about 15-30 seconds (does not have = to be=20 long) that I do not have much success getting air out of the = block.  It=20 seems to take that velocity of coolant flow to drag the water out of the = block.
 
You have over 700 cubic inches of core, so that = should be=20 plenty for cooling a two rotor. 
 
A multi pass radiator (two pass in your case) = can require=20 more coolant pump flow as indicated by this extract from a pretty = respected name=20 in racing/cooling circles:
 
   Double pass=20 Double pass radiators = require 16x=20 more pressure to flow the same volume of coolant through them, as = compared to a=20 single pass radiator. Triple pass radiators require 64x more pressure to = maintain the same volume. Automotive water pumps are a centrifugal = design, not=20 positive displacement, so with a double pass = radiator, the=20 pressure is doubled and flow is reduced by approximately 33%. Modern = radiator=20 designs, using wide/thin cross sections tubes, seldom benefit from = multiple pass=20 configurations. The decrease in flow caused by multiple passes = offsets=20 any benefits of a high-flow water pump.
 
 
Again, these are just back of the envelope = calculations=20 based on a great deal of assumption about your parameters.  My gut = feel is=20 that 700 cubic inches should have no problem cooling your installation = at those=20 power settings even being a double pass radiator.  So I would look = else=20 where.
 
 You indicate you have an approx. 80F delta = T across=20 your radiator core with the coolant temp a 210F.  You have a fan = which=20 apparently has the spec to draw 970 CFI across the 11" dia of the = Fan. =20 Lets assume that was the flow through the entire core.  Then that = would=20 give you 970*.0765 =3D 74 lbm/min of air mass.
 
Q =3D 75 * .25 * 80 =3D 1500 BTU/Min just due to = the flow=20 resulting from your fan - it would seem that plus whatever flow you are = getting=20 from your prop - Prop??. 
 
Hey, this  dumb question just occurred to = me=20  -  I assume you are running with a prop?? in a tractor=20 configuration.  I lose track of who has what.
 
 
Ed
 
 
 
 
 
 
----- Original Message -----
From:=20 Bill=20 Bradburry
Sent: Wednesday, October 03, = 2007 5:12=20 PM
Subject: [FlyRotary] Re: = Problem?=20 [FlyRotary] Re: Coolant Water Pressure

I have an = aluminum=20 double pass radiator with the finned core size of about 18.25 X 18.25 = X=20 2.25.  It is behind the engine and leaning rearward at the top at = about a=20 30-35* angle.  The water from the engine enters on the left lower = and=20 crosses the bottom half of the radiator to the right side then rises = and goes=20 back across the top of the radiator and exits the top left side and = returns to=20 the engine.

My radiator = cap is at=20 the top right corner of the radiator at the point where the water = starts its=20 second pass through the top half.  My pressure port is just below = the=20 radiator cap.  The pressure sending unit is in a =93T=94 with the = hose which=20 goes to the =BC=94 port at the top of the rear iron connected to the = other side of=20 the =93T=94.  I thought that this hose could have some effect on = the=20 pressure, but I am not certain why it = would.

 

Any air in = the system=20 should either rise to the top of the radiator, or if it was trapped in = the=20 block, it could come through the hose to the radiator.  All air = should be=20 found therefore? Under the radiator cap.  I have never found any = air=20 there.

 

I think I = found out a=20 little something about the fuel system today.  I only put a few = gallons=20 in the right tank and have been checking for leaks and running the = engine on=20 this fuel.  I wanted to run it down to the =93non-usable=94 level = and then do=20 the same thing with the left tank.  So I have been really low on=20 fuel.  My pressure has been holding, but I thought that I could = hear=20 bubbles from time to time going through the=20 lines.

 

Anyway, = before, I=20 could get a good start by setting the mixture at about 4 PM oclock and = it=20 would fire up in a couple of blades.  Today, I tried hitting the = primer=20 button a couple of times and it would start and immediately die.  = I=20 finally had to set the cold start on and leave it on just to get the = engine to=20 run!  Finally after it warmed up, it ran with the mixture set at = 12=20 oclock, but it was not steady.  As my fuel ran out, the pressure = dropped=20 finally to about 28 lbs and the engine started its death rattle.  = I shut=20 it off at that time.

 

The = temperature had=20 risen to 210* the ambient temp was 87-88* and the air after the = radiator was=20 168*  This is with my radiator fan running.  (11=94 and 970 = CFM)=20 probably about 10-12 minutes of running the=20 engine

.

My oil temp = was only=20 160* and the air temp after the oil cooler was 145* , I think that = this would=20 gone higher if I ran longer, because the oil in the pan was up to = 170-180* or=20 so.  The pan holds 5 qts, 8 qts in the=20 system.

Water = pressure was up=20 to 22-23 lbs and oil pressure was 70 lbs.

 

All my temp = probes=20 are within a degree or so of one another and with a mercury = thermometer in the=20 hangar when reading ambient temp and the engine is cold.  I think = they=20 are all correct.

 

I have the = air/fuel=20 ratio setup that comes with the EM-2, but it doesn=92t work till the = O2 sensor=20 gets to about 800* or so, no help on trying to figure out starting=20 ratio.

 

The timing = brings up=20 a good point.  I got the Renesis out of a wrecked car with 1800 = miles on=20 it, so the timing is set to the factory setting for the Renesis.  = I have=20 never checked it.  Does anyone know what the factory setting = would be for=20 the Renesis??

 

Staging is = a good=20 point, but I think that you are correct about having enough fuel to = run a low=20 speeds and not enough to run faster.  I was running out of fuel = and=20 probably didn=92t have enough to rip it.

 

You really = have good=20 insights when you are helping folks.. You are pretty right on with = your=20 advice.

 

Thanks,

Bill = B  (Must=20 mow yard=85Must mow yard..)

From:=20 Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Ed Anderson
Sent: Wednesday, October 03, = 2007 12:53=20 PM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Re: = Problem?=20 [FlyRotary] Re: Coolant Water = Pressure

 

Yes, too hot for that = rpm, I=20 agree.

 

Assuming  you = followed the=20 good suggestions offered by Al, Lynn and others regarding getting all = the air=20 out of the block - really important!  I almost cooked engines two = times=20 because of excess air in the coolant system.  Here is something=20 that  may quickly tell you something about the air you may have = in the=20 system.

 

  I can't recall = what type of=20 radiator set up you have, but with the Two GM cores I use which = are=20 mounted vertically, you can touch the side tank of the radiator = and=20 determine if there is air in the system.  In my case, = if I do a=20 complete drain and refill of the system, on the first run up the = core's tanks=20  will be hot approx 2/3 of the way up and then they are much = cooler -=20 indicating that the remaining 1/3 of my core is filled with air.  = It=20 generally takes me 3 runups reaching 5000 rpm before I can = touch =20 the core tanks and find them hot all the way from top to = bottom.  So=20 depending on your radiator set up that might be something you can = quickly=20 check.

 

If the mixture is too = lean, you=20 can get a backfire out the intake, too rich and its generally the = exhaust -=20 where unburned fuel cooks off.  So that and black smoke would = indicate to=20 me  too rich a mixture.  I presume you do not have an = Air/Fuel ratio=20 indicator - strongly recommend you get one, that tells you right away = whether=20 you are running rich or lean.  Even a cheap one can be a = tremendous help=20 in finding out whether too rich or too=20 lean.

 

One thing you may want = to check is=20 your ignition timing.  If using Tracy's EC2 you need to set the = static timing=20 around 35 Deg BTDC.  The EC2 backs off 10 deg from that (25Deb = BTDC) as=20 its default starting point for ignition timing.  So if you set = the static=20 timing to say 25 Deg then the EC2 would be having the engine operate = at a 25 -=20 10 deg =3D 15 Deg BTDC which is pretty retarded timing for the =20 rotary.  OR if you set it too far advanced then the timing might = be too=20 advanced.

So just recheck it when = you get=20 the chance.

 

Another possibility is = your=20 injection system might not be staging properly. IF that were the = case,=20 the engine might work fine below the staging point but not above = it. =20 Could possibly be a sticking secondary injector (if too rich or=20 lean).   But, that is a bit down the likely list.  = Something=20 impeding the fuel flow might provide sufficient fuel and low rpm but = not=20 sufficient to run at high rpm.

 

Hope some of this=20 helps

 

Ed

 

Ed Anderson
Rv-6A = N494BW Rotary=20 Powered
Matthews, NC
eanderson@carolina.rr.comhttp://www.andersonee.com
http:/= /members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.dmack.net/mazda= /index.html

 

 

 

 

 

 

----- Original Message = -----=20

From: Bill=20 Bradburry

To: Rotary motors in = aircraft=20

Sent:=20 Wednesday, October 03, 2007 11:23 = AM

Subject:=20 [FlyRotary] Re: Problem? [FlyRotary] Re: Coolant Water=20 Pressure

 

Ed, this = is at=20 about 2000 rpm.  Like a fast idle.  I am getting all kinds = of fuel=20 cut like stoppages if I try to run the engine faster.  I = haven=92t seen=20 more than about 3700 rpm, but I just started it and have not tried = to tune=20 anything.  I figure I will have to run longer to get it tuned = and the=20 cooling is holding that back.

 

Speaking = of that,=20 you guys were talking a while back about the effects you see when = the engine=20 is too lean, or too rich.  Talking about backfires, etc and = what each=20 effect represents.  I have forgotten what means what=85senior = days, not=20 moments!

Do any of = you=20 remember how that went?  I am having some problems getting = started and=20 am not certain if I am too rich or too lean.  I am getting = backfires=20 out the exhaust at times and smoke from the exhaust at that time.=20 (black)

I ran the = batteries=20 down yesterday trying to get started due to this.  When I = originally=20 started the engine, I flooded it.  I am trying to prevent this = now and=20 am concerned that I may not be using enough=20 mixture.

 

Bill=20 B

 

From:=20 Rotary motors in = aircraft=20 [mailto:flyrotary@lancaironline.net] On=20 Behalf Of Ed Anderson
Sent: Wednesday, October 03, = 2007 10:05=20 AM
To: = Rotary motors in aircraft
Subject: [FlyRotary] Problem? = [FlyRotary] Re: Coolant Water = Pressure

 

Bill,=20

 

You indicate you get = overheating=20 after 10-15 minutes run time.  I may have missed it, but is = this at=20 idle, max throttle or what.  Also what is your OAT.  If at = idle or=20 low power then, yes what you are seeing is not what it should = be.  On=20 the other hand, if at WOT or high power settings, then 10-15 minutes = run=20 time would be indication of a great cooling capacity.  I can = not run my=20 engine more than a minute or two at WOT on a 80F day without temps = getting=20 into the 200F range.  But, that is at 5800-6000 rpm.  At = idle, the=20 temps stabilize and I can idle all day with safe=20 temps.

 

My coolant system runs = with no=20 air cushion and yes, I get a hydraulic "lock" pressure reading of as = high as=20 25 psi immediately upon engine start up.  After a 30 - 60 = seconds of=20 running the pressure  drops down to zero and then after a = few=20 minutes running builds back up as the coolant warms up to operating=20 temperatures. 

 

Plenty of suggestion = have been=20 made about what to check - all good. =20

 

Good=20 luck.

 

Ed

 

Ed Anderson
Rv-6A = N494BW=20 Rotary Powered
Matthews, NC
eanderson@carolina.rr.comhttp://www.andersonee.com
http:/= /members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.dmack.net/mazda= /index.html

----- Original = Message -----=20

From: Al = Wick=20

To: Rotary motors in = aircraft=20

Sent:=20 Wednesday, October 03, 2007 9:30 = AM

Subject:=20 [FlyRotary] Re: Coolant Water = Pressure

 

Bill, the definitive = test is=20 the one I described below. Really encourage you to do it as = described.=20 Resist assumptions. Convert your ideas to=20 measurements.

 

-al=20 wick

----- Original = Message -----=20

From: Bill Bradburry=20

To: Rotary motors in = aircraft=20

Sent:=20 Wednesday, October 03, 2007 6:08 = AM

Subject:=20 [FlyRotary] Re: Coolant Water=20 Pressure

 

I = think that I=20 would see air under the radiator cap if I had a compression gas=20 leak?  I never see any air.

To = check a=20 piston engine for head gasket leaks, you would put the cylinder = at TDC=20 and pressurize the cylinder to about 150 lbs with compressed air = and=20 check the radiator for air bubbles=85How do you check a=20 rotary?

I = will check=20 the pressure sender against a mechanical gage. =20

There = is=20 obviously a heating problem, but I think the pressure is higher = than it=20 should be until just ready to boil.  I shut the engine off = at 210*,=20 and at 22+ lbs, the boiling point should be well above=20 250*??

 

Thanks for the=20 suggestions of where to look, = guys=85

 

Bill=20 B

 

From:=20 Rotary motors in = aircraft=20 [mailto:flyrotary@lancaironline.net] On Behalf Of Al p = Wick
Sent: Tuesday, October = 02, 2007=20 7:49 PM
To:=20 Rotary motors in=20 aircraft
Subject: [FlyRotary] Re: = Coolant=20 Water Pressure

 

Your coolant reservoir should be above = engine.=20

 

1) If it is, remove two cups of air = from the=20 reservoir. Then repeat your test. =

2) If you now see pressure rise = above 22=20 psi within 5 minutes of cold start, you clearly have compression = gases=20 leaking into cooling system or bad=20 gage.

 

3) Air in the block is 10 times more = significant=20 than any other cooling factor. Make darn sure you don't have = any. It=20 causes local boiling, high temps, strange=20 behavior.

 

Operating with two cups of air under = cap is an=20 important safety and diagnosis advantage. Everyone should do it. = With=20 that two cups, you only see 22 psi if you have a genuine = problem. You=20 only see 0 psi if you have genuine problem. The pressure is then = a very=20 fast and reliable indicator of system integrity. So two cups of = air has=20 no negative effect on system efficiency, just a substantial = improvement=20 in safety. Only time it could be a negative would be if your = reservoir=20 was way too small, way too low, or flowed way too much=20 coolant.

 

Since you describe high temps AND = pressure, I=20 suspect you have temperature = problem.

 

I deliberately overheated my engine = many times=20 so that I was intimate with pressure and temperature patterns.=20 Then tested various concepts. Don't recommend you do the=20 same.

 

-al = wick

 

 

On Tue, 2 Oct 2007 12:38:55 -0400 = "Bill=20 Bradburry" <bbradburry@bellsouth.net>= =20 writes:

I just recently = got my=20 Renesis started again after finishing my cowl.  I seem to = be=20 getting very high coolant pressures.  I can only run the = engine=20 about 10-15 minutes before hitting the redline at 210*.  = My water=20 pressure is at 27 Lbs at that time.  I only have a 22 Lb = radiator=20 cap, so I assume that I am blowing into the recovery tank, but = I have=20 not confirmed that.  My oil temp has never exceeded about = 165*.  It might have gone higher if I could have run=20 longer???

 

This whole water = pressure=20 thing has me a little baffled.  Since this is a closed = system and=20 the only way pressure can build is due to the expansion of the = coolant=20 after heating???, I am confused by some comments that have = been made=20 from time to time.  I remember something that Tracy = said about=20 his pressure would build for a time, then go to zero.  It = seems=20 to me that the pressure should correlate to the temp pretty = closely=20 since it is a closed system??

 

Can someone = enlighten me a=20 little on the science of this pressure?  It seems to me = that=20 there could be some pressure build up on the positive side of = the=20 pump, but it would go negative on the suction side, so the net = effect=20 of the pump should be close to = zero??

 

Also, my Renesis = had only=20 1800 miles on it when I bought it, so I did not have to tear = it=20 down.  As a result, I am somewhat in the dark as to how = the water=20 flows through the system.  Could someone help me with = that? =20 I had to remove the thermostat tower for height clearance , so = I made=20 an adapter plate that takes water from the top outlet of the = pump and=20 sends it to the radiator (double pass), then from the = radiator, it=20 returns to the lower inlet of the = pump.

 

Thanks,

Bill=20 B

 


-al wick
Cozy IV powered by = Turbo Subaru=20 3.0R with variable valve lift and cam timing.
Artificial=20 intelligence in cockpit, N9032U 240+ hours from Portland, = Oregon
Glass panel = design, Subaru=20 install, Prop construct, Risk assessment=20 = info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html

-Al Wick
Cozy IV powered by Turbo = Subaru 3.0R=20 with variable valve lift and cam timing.
Artificial = intelligence in=20 cockpit, N9032U 240+ hours from Portland, Oregon
Glass panel design, = Subaru=20 install, Prop construct, Risk assessment info:
htt= p://www.maddyhome.com/canardpages/pages/alwick/index.html<= /SPAN>

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