Glad you didn't Mark!
I didn't run into this problem due to my obsession with weight. That was the only reason I made an aluminum mounting bracket for mine. Never would have guessed that steel would be a problem.
Tracy
On 9/17/07, Mark Steitle <msteitle@gmail.com> wrote:
Bill,
I don't seldom give up on a problem, but I came awfully close this time.
Mark
On 9/17/07, wrjjrs@aol.com <
wrjjrs@aol.com> wrote:
Sure can't Mark,
I wasn't trying to impugn the RX-8 parts either. There are always a few idiosyncrasies with any part set. I have seen parts not function properly because they put out too strong a signal. On some of the older magneto CDI 2 cycles I worked on the eletronic advance wouldn't work because the thyristor trigger was always getting too strong a pulse. (A single wave rectified device) The solution was simple we doubled the gap which got the voltage to the thyristor trigger back in the correct range. we then got 25° of advance instead of 5°. The moral is to never give up, and keep a record of what you have done so you don't cover the same ground twice. That is unless you want to to verify the trouble. You then hope it's repeatable!
Bill Jepson -----Original Message----- From: Mark Steitle < msteitle@gmail.com> To: Rotary motors in aircraft <
flyrotary@lancaironline.net> Sent: Mon, 17 Sep 2007 1:27 pm Subject: [FlyRotary] Re: One for the smart guys
Bill,
I have not heard of any problems with the Renesis CAS in the RX-8's. I'm not sure this qualifies as having a smaller signal. We measured approx. 30 volts at higher rpm. My engine has been running great ever since I replaced the CAS bracket. I got my trigger wheel through Bob Mears, but had to buy the whole assembly (hub, pulley and trigger wheel). But Bob's price was very reasonable, and he even delivered it to my hangar. You can't beat that kind of service with a stick.
Mark
On 9/17/07, wrjjrs@aol.com <
wrjjrs@aol.com> wrote:
Mark, I'm building a 20B also so I was interested in your problem. The renesis CAS uses the small magnet/reluctor system right? We had many of this style on the motorcycles, and they were more problematic than the moving magnet type. Probably due to a smaller signal output. One of the systems that has been discussed here before, (the old mopar EI) had a bunch of metal plates close by. They must have used a stronger magnet!
Bill Jepson
-----Original Message-----
From: Mark Steitle <msteitle@gmail.com>
To: Rotary motors in aircraft <
flyrotary@lancaironline.net>
Sent: Mon, 17 Sep 2007 10:07 am
Subject: [FlyRotary] Re: One for the smart guys
Bob,
I tried to reply twice to your message but the list server didn't like the attachment. So, I'll try to explain it here.
I got a hint from the shop manual, in the section on ignition where it talks about small filings of ferrous metal powder adhering to the CAS and causing problems with engine control. Sounded like it could apply to a big ferrous metal bracket too. In the end it was just a hunch that paid off big time. So, the moral of the story is to keep ferrous metals away from the CAS.
Mark
On 9/17/07, Richard Sohn <unicorn@gdsys.net> wrote:
Bob,
you can not really meassure it, unless you use a setup intensionally looking for this particular issue. Even than, you can only compare it to some other setup. I have gone throu quite a bit of that using my own designed trigger finger for the single rotor, using a pickup coil from the Mazda distributor and the Renensis CAS. On the first design, the end was at 4500RPM.
The problem is the flux change rate, which is getting more critical at high RPM.
The safest approach is to have a hard look at the stock installation and copy that as much a possible. Do not get closer with any ferritic metal than in the stock installation.
I should have caught Marks problem, but I was under the impression he was using stock installation.
The setup I am using on the single rotor is tested up to 8k with no problem.
FWIW.
----- Original Message -----
Sent: Monday, September 17, 2007 9:36 AM
Subject: [FlyRotary] Re: One for the smart guys
I would like to know how you figured it out? thats a tough find.
Dennis, Nope, part of the conversion was to install the stock Renesis timing gear. The problem has been fixed and the Renesis gear is still there. Just in case you're wondering, the timing gear wasn't installed backwards nor was it clocked incorrectly.
Mark
On 9/15/07, Dennis Haverlah <clouduster@austin.rr.com
> wrote:
Mark, Was the frequency of the teeth going by the wheel too high for the CAS? Dennis H. Mark Steitle wrote:
Bob,
While good things to check, neither of these were the cause of my problem. At Tracy's suggestion, I changed the air gap on the CAS to no avail.
Mark
On 9/15/07, bmears9413@aol.com <
bmears9413@aol.com> wrote:
I haven't cheated and looked at the manual.....since your gonna tell us anyway...eventually...but problems I've had before in race cars...plug wires running parallel to each other, and too large of air gap in the pickup in the distributor. Close???
Bob Mears
Supermarine Spitfire
-----Original Message-----
From: Mark Steitle <msteitle@gmail.com
>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Sat, 15 Sep 2007 7:53 am
Subject: [FlyRotary] Re: One for the smart guys
Ed,
You are getting closer when you stated that it must be erratic ignition. (I wish I had someone to give me hints). Yes, the ignition timing was too far advanced, but retarding the timing didn't correct the problem. The coils are LS1 units, 6 ea, so any individual coil isn't firing any more often than on a 2-rotor. So, what's causing the erratic ingition? That's the question.
Mark
On 9/15/07, Ed Anderson <eanderson@carolina.rr.com
> wrote:
Hey, No Fair! Mark. Most of us do not have a Renesis shop manual. But, lets see the old CS had three wires, the new one has two wires - I get it - there is a wire missing {:>).
So it sounds like the problem was indeed ignition - well, its almost always either fuel or spark causing a problem. So if fuel is more or less ruled out it defaults to ignition. It probably wouldn't be a rev limiter as they simply cut out above a certain rpm. So either your ignition timing somehow was off at higher rpm (too much advance?) or else your ignition was erratic in its firing (such as exceeding the capability of the coils to recharge between firings - unlikely in this case).
But, without a shop manual to give me more insight, I must say I'm out of ideas.
Ed
----- Original Message -----
Sent: Friday, September 14, 2007 10:52 PM
Subject: [FlyRotary] Re: One for the smart guys
Now Rusty!!! That's too obvious. ;-)
OK, another hint... I got a hint of what might be causing my problem from the ignition section of the Renesis shop manual.
Mark
On 9/14/07, Russell Duffy <rusty@radrotary.com
> wrote:
OK, I'll give you a hint... it was related to my decision to change over from the original CAS to the Renesis CAS. I got that bright idea from last year's rotary get together at Tracy's.
I've got it. YOU were the problem :-)
Rusty
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