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Glad to hear you are back in the air, Joe.
Joe, Oil pressure sounds fine to me in the 4000 rpm range. However, I get 70 psi at 5000 and above and its been that way since first flight in 1998. I forget the details of your project, but from your e mail it sounds like you have an fairly straight forward oil installation. I know the racers sometimes have oil foaming at higher rpm which can reduce oil pressure (tiny air bubbles in the oil), but have not know it to be a problem with the flying crowd. Also I have found high oil temps can cause a 5-10 psi drop (depending on how hot). My system if filled with 4 1/2 quarts of oil, so I would say you have plenty of oil.
Also forget your prop dia and pitch, so can't comment on whether you are over propped, but that is not that uncommon on first flights as I think we all over estimate the power we are going to initially produce {:>). I will tell you that in almost all cases power increases as tuning and associated things are improved - so don't cut down the prop, just yet. My initial flights were in the power range or around 135-140 HP because I had initially put a racing induction system, and I was certain I was going to produce gobs of power because the components were all race components - didn't work out that way. Unless you have a pretty restrictive filter I doubt you will find removing it makes much difference. I was using a 2.17 gear box and a 68"x72" prop for reference.
You'll work all of this out, nothing I see to be alarmed about.
Ed
----- Original Message ----- From: "Joe Hull" <joeh@pilgrimtech.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Wednesday, May 31, 2006 1:35 PM
Subject: [FlyRotary] Status Update
Since I got my engine back in the plane two weeks ago a couple of things
have happened I thought I should report on. First, I got my medical back
(sleep apnea issue resolved with the FAA until next year). Second, it
stopped raining for a couple of days and I was actually able to go try out
the re-built engine.
Oil pressure is now about 59-60 in the 4000's RPM range. Still goes down
slightly to 54-57 after 5000RPM. But that's a lot better than it was. Am I
in the ball park now? The Haynes manual indicates that oil pressure should
be north of 60 above 3000RPM.
Now that I have reasonable oil pressure and can push the engine a little
harder I'm seeing higher oil temps. Water temp is OK no matter what because
the electric fan kicks on and keeps it under 190. But the oil temp is about
205F at 4500RPM (54F OAT) and about 215F at 4900RPM. So, I'm planning some
cowling changes to see if I can get more "suction" out of the cowl exits -
and may add another exit area where I know there is low pressure.
Still not happy about the lack of power. I know I'm still over propped for
this engine. I put the plane into a dive to get the RPM up to 5700RPM (best
HP) and then level out and it cannot maintain the 5700RPM. About 5000-5200
is the maximum I can maintain (depends on altitude). I'm going to try taking
the air filter out and see if that has any impact at all on RPM.
Exhaust noise - my wife said the plane was way quieter than a "normal"
airplane when I flew over our house yesterday at about 1500ft AGL. Of course
I was only turning 4200RPM so I could stay at about 100kts. Also a guy at
the airport said it sounded like I have a sewing machine in my airplane and
not an engine. I'm not sure whether he meant it was a loud sewing machine or
a quiet one (I was on my take-off roll and wasn't in a position to chat)!
Thanx,
Joe Hull
Cozy Mk-IV #991 (In Phase1 Flight Test - 22.4 hrs flown)
Redmond (Seattle), Washington
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