Mailing List flyrotary@lancaironline.net Message #8492
From: DaveLeonard <daveleonard@cox.net>
Subject: Two problems solved, 2 more pop up...
Date: Sat, 22 May 2004 23:15:12 -0700
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Message
Rusty,  I now know what you mean about cooked items under the cowl.  I have been doing a lot of running with the cowl on lately.  Luckily cooling is no longer an issue.  Can run more than an hour under 2300 RPM with occasion bursts up to 35 MAP for up to 15 sec without overheating.  The big key in that was running 80% water antifreze and some water wetter.  Oil temps never a problem.
 
New problem:  melt down after shut down.  That turbo has a lot of very hot mass.  I flow enough air through the cowl when running to keep things cool.  Right after shut down the cowl is just luke warm to the touch.  But 5 min after shutting down the turbo side of the cowl is too hot to touch on the top and I can smell resin.  It gets a little soft to tap on it and it is starting to look a little mottled and maybe yellow (if I let my immagineation run away).  I have seen a couple of RVs with drop down hatches in the top cowl to let heat out after shut down.  Does anyone have an idea about how hot I can let the fiberglass get?  Bright Ideas?
 
Alternator Noise Fixed:  I installed a certified (that was probably my first mistake) alternator filter.  It was only 15 micro Farads and cost $40.  It made a slight improvement.  While at the local industrial liquidator I found another capasitor - 45000 micro Farads at only about 4x the size and similar weight to the certified version.  Cost?...  Marked at $1 but   "Eh, take it, I don't feel like writing up a receipt" - so I tipped him a dollar.  However, it will never get installed because on a whim I decided to try out my TELEX ANR instead of my $75 headset.  Even with the ANR turned off the alternator noise was all but gone.  I guess the filtering is good enough to catch that.  Hmmm.  Cool.
 
New Problem: RMI tach no good.  According to my RMI engine monitor I have about 4300 RPM at 24 MAP.  At 29 MAP I still only have about 4500 RPM and at 35 MAP I am still at 4500 RPM static.  I dont buy it because it sure sounds different (faster).  So I have to install an accessory Tachometer....  Tracy, where was the Engine Monitor when I was building the pannel?  :-)    I still have holes in my mixture map as every now and then I pass through a hole and the mixture goes all haywire.
 
Old problem still not fixed:  Low RPM: to keep it running it needs to be rich, so much that I billow smoke down 400 yrds of hangars.  It comes out in billows every 2-3 seconds.  Above 2200 RPM there are no problems (never were).  Will be trying some 460cc injectors instead of the 550 primaries I currently have.  If that dosen't work, the 2200 RPM will have to be the idle speed.
 
Cowl flap is installed and looks good, but dosen't seem to make any difference in temp on the ground....  oh well.
 
First flight within a month.
 
Dave Leonard (In red because Rusty alway takes the blue)(secret manifold my A## - lets hear the plan)
 

I should be able to get 200 HP out of my engine at 7K+ rpm, which is much healthier than running boost.  If that all works out, I think it will move an RV-3 along well enough.  I certainly don't miss the extreme nose heavy condition, nor the cooked items under the cowl.  I certainly won't say that I'll never go back to boost, but it just might be a little different next time :-)

Rusty (intake shaping done, boring secondary injector holes) 




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