flyrotary@lancaironline.net Mailing List Archive

Mark,

Thanks for the reply.

The compression gage I have has a button on it that acts like removing the valve. Also, the reading on the front rotor are higher.

Yes, while it is a difficult to determine since the needle jumps around, I think I have trained myself well enough to get the readings.

I am getting 60 psi on the rear rotor on all three pulses AND when I release the button the cumulated psi is still at 60. I get the same events on the front, however, on the front, the readings are at 80 psi.

I am my mothers primary care giver and have to tend to some errands for her today (my "Sunday") so I will not likely get to the hangar today but I will be pondering what is going on and be keeping my ears and eyes open as I can usually make some access to the internet.

Again, while resigned to the idea of cracking open the engine, I am concerned that whatever the problem is may be missed AGAIN since I just went through this.

I also meant to mention that the engine turns over smoothly and I do not hear/feel any grinding of parts.

Thanks again.

Chris

From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of Mark Steitle [msteitle@gmail.com]
Sent: Monday, February 14, 2011 5:00 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Low Compression in rotor 2...still

Chris,

Sorry to hear that you're still having hard starting problems. Just for clarification, are you reading 60 psi on all three rotor faces? Did you remember to remove the schraeder valve from the compression gauge? Otherwise, you're reading a compilation of all three, not each individual pulses. You should get three separate readings. If one is high, followed by two low readings, then it is likely a bad apex seal as a single apex seal will cause low readings for two rotor faces.

Mark

On Sun, Feb 13, 2011 at 11:51 PM, Chris Barber <cbarber@texasattorney.net> wrote:

oh, and the initial/build lube has been with Marvel Mystery, Vaseline, assembly lube with some cleaning fluid mixed in too. I am using Royal Purple Synthetic for my oiling, even though I broke the engine in initially with dino oil.

Chris

From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of bktrub@aol.com [bktrub@aol.com]
Sent: Sunday, February 13, 2011 11:27 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Low Compression in rotor 2...still

This is a puzzler. How are you lubing the apex springs? Not that that has anything to do with it, just wondering. Also wonder how funtional the apex springs are when the motor is spinning- shouldn't centrifugal force drive the seals out against the rotor housing walls?

I hate to be a pessimist, but did you check the side seals and corner seals also?

Brian Trubee

-----Original Message-----
From: Chris Barber <cbarber@texasattorney.net>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Sun, Feb 13, 2011 7:29 pm
Subject: [FlyRotary] Low Compression in rotor 2...still

To remind y'all, following very hard starting, I discovered bad apex seal springs in my rotor 2 most likely due to detonation. I cracked the keg and replaced the rear apex springs and sealed it all back up. While apart, I did not discover any damage other than the bad springs.

I have been trying to tune the engine, however, even using BOTH my EC2's , I am still having problems with very hard starting. When I do get it to start it is at full lean and I believe only if I switch over to B. Once started I can take the mixture from full lean to a more moderate setting (even if the tuning is still lacking) and it will run on A or B about the same. I have reset A to factory settings. I do have a bit larger injectors, per Mistrals recommendation, but did crank her up to 22. MAP and adjust Mode 3 once started to just over the mid point per the EC2 manual.

It takes an extended period of time of cranking (maybe 50 or 60 seconds...betting my starter is hating me) before it starts and then kinda just starts running as a continuation of the starter being turned, instead of the engine actually "firing up".

I pulled the plugs to check inside and unlike before all the apex seals are nice and springy, HOWEVER, when I do a compression check I am only getting about 60 psi on the rear rotor. I am getting about 80 psi on the front rotor, which is what I expected.

Guys and Gals, I just rebuilt this rear rotor. I am confidant that I got it together properly...but, obviously, I shouldn't be so confidant as the facts is the facts. The rear rotor is only 60 psi which IF I understand correctly would lead to hard starting (and perhaps some rough running as the engine does not seem as smooth when running as it has in the past).

I have been getting it to run with much effort over the last few weeks but kept it at lower power. Today, however I did run it up for several seconds and was able to produce a steady 6300 RPM at 33.4 MAP.

I had it suggested that the new springs needed some time to "set", but I am not really thinking this holds water...or compression for that matter. I also tried squirting in some MM oil and compression did come up a bit, but the REALLY hard start remains.

I am once again mostly resigned to tearing open the engine to see what I must have missed. But since I am pretty sure I did it right before WHAT, pray tell, may you fine gentlepersons suggest I look for when/if I open her up again???? Or, even better, suggestions that would prevent a teardown. FYI, the plugs looked like I would have expected....brownish ashy with no oil build up. Also, I am not having any current indication of coolant in the chambers (don't ask me how I know how to look for that tell tale sign [-(

Please feel free to ask probing questions regarding my method and or attempts.

I am betting ya'll are getting tired of hearing from me.....

Chris Barber

Houston