I prefer easy math (can fit in one line):

 

Rotary: 1 spark/plug/revolution, 1:1 spark plug:coil,  at 8000 RPM=  8000 spark/min/coil

Car: .5 spark/plug/revolution, 8:1 spark plug:coil, at 4000 RPM= 16000 spark/min/coil

 

So the rotary in our application has half the duty cycle on the coils for equivalent engine work loads.  I think maybe some cars have 2 coils, which would make the rotary at 8000 rpm the same duty cycle on the coils as the car at 4000 rpm.

 

Did someone already say that?

 

Dave Leonard

 

On 1/18/06, Ed Anderson <eanderson@carolina.rr.com> wrote:

 

----- Original Message -----

From: Ed Anderson

To: Rotary motors in aircraft

Sent: Wednesday, January 18, 2006 5:01 PM

Subject: Re: [FlyRotary] Re: LS1 Coil Failures

 

Cause still to be resolved, Bob.  Too soon to worry, but, if truly a problem better to find it now than at 2000 MSL on some take off down the road.  Although with 6 (20B I presume) you can stand a coil failure a bit better than us two rotor.

 

Ed A

 

----- Original Message -----

From: bmears9413@aol.com

To: Rotary motors in aircraft

Sent: Wednesday, January 18, 2006 3:44 PM

Subject: [FlyRotary] Re: LS1 Coil Failures

 

Plus I really hate reading all this about the LS1 coils....I just purchased 6 yesterday.

 

Bob Mears 

 
-----Original Message-----
From: Mark R Steitle <mark.steitle@austin.utexas.edu >
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Wed, 18 Jan 2006 14:24:20 -0600
Subject: [FlyRotary] Re: LS1 Coil Failures

Bill,

I feel it is a fair assumption that the LS1 coil was never intended to run at 12,000 rpm, as would be the equivalent of what we?re doing with the rotary at 6,000 rpm.  So, we?re clearly operating it outside the design range.  Does this shorten their life?  Don?t know, but Tracy?s experience seems to indicate this could be the case.  Couple this with other extremes, such as temperature and frequency and they might not be up to the task. 

 

The coils on my 126,000 mile LS1 truck are all factory stock.  No failures (knock on wood).

 

Mark S. 

 

---

From: Rotary motors in aircraft [mailto: flyrotary@lancaironline.net] On Behalf Of wrjjrs@aol.com
Sent: Wednesday, January 18, 2006 1:27 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: LS1 Coil Failures

 

 Mark,

There may well be a duty cycle problem, but I doubt it. Older ignitions used a single coil of similar type firing all 8 cylinders. I would be more likely to suggest it was a "bathtub failure curve" failure of the solid state "trigger" circuit.

Bill Jepson

-----Original Message-----
From: Mark R Steitle < mark.steitle@austin.utexas.edu>
To: Rotary motors in aircraft <flyrotary@lancaironline.net >
Sent: Wed, 18 Jan 2006 10:51:47 -0600
Subject: [FlyRotary] Re: LS1 Coil Failures

Sorry, that's what I get for doing "head math".  Anyway, my point is still valid.  It fires 8 times more often in the rotary than in the truck/auto.  Could the duty-cycle be the culprit?  It would be interesting to see the specs on these coils.

 

Mark S.