| Kelly,
Yes, the slide throttle is history, mainly because,
1) I concluded that the location of the primary injectors being upstream from the slide was causing puddling of the fuel and surging, and hence poor low speed/idle characteristics, although this was not a problem at mid to WOT. I could have relocated the primary injectors but there were other issues as well (see 2 through 5)
2) I suspected cross-feed from one port to the next during low throttle operations, although I couldn't verify that was happening I felt it may be contributing to the rough operation mentioned above,
3) It dripped fuel upon shutdown, not a lot, but it caused me some concern,
4) the nature of the design prevented me from balancing the individual rotors, and
5) it required a modest force to operate; the new TB's are silk smooth.
I located a triple-set of like-new 46mm 1 BBL throttle bodies from a Sea Doo or snowmobile that looked like would work with very little modification. It required a new throttle shaft to be fabricated since it was one piece and the spacing was wrong for the 20B, but Bob Darrah and his Bridgeport were happy to help me with that. I'm very happy with the end result.
The nature of the p-port necessitated the TB's to be located very close to the ports, else I would have gone with a larger single TB feeding into an airbox like most have done. Not sure that wouldn't work here, but I've read that with the p-port engine the TB should be as close as possible to the ports. These TB's have the injector bungs cast into the body just downstream of the butterfly, exactly as I needed. Low end performance has improved considerably. I just need to figure out why the #1 rotor cuts out in mid-range.
Mark S.
On Thu, Mar 22, 2012 at 3:44 PM, Kelly Troyer <keltro@gmail.com> wrote:
On Thu, Mar 22, 2012 at 9:57 AM, <bktrub@aol.com> wrote:
Yes, that change certainly did the trick. I've only flown once since due to weather, but the engine runs great. First thing I did after tuning A was to copy to B before flying. Now I'm re- doing the cooling air scoop so that it doesn't look like a hideous wart underneath the fuselage. The cooling system works great, but it was kludged together while trying to arrive at a workable configuration.
Brian Trubee
-----Original Message----- From: Tracy < rwstracy@gmail.com> To: Rotary motors in aircraft < flyrotary@lancaironline.net>
Sent: Thu, Mar 22, 2012 6:14 am Subject: [FlyRotary] Re: #1 rotor cutting out
Sorry Mark, that came out a bit harsher than I intended! BTW, the current
version of the EC2/3 software (since about two months ago) now programs both A &
B when you tune A. You can still program B differently when running on B if
desired as changes to B do not affect A.
On your rotor 1 symptoms between 3800 and 5000, I was wondering if you still had
the resistor between CAS and EC2 that you were using to try and make the Renesis
CAS work. If so, you might try eliminating it since you are using the original
CAS. That's one reason I was anxious to hear if B had the same symptom.
Sounds like the CAS sensor circuit change I installed in (Brian's ?) EC2 13-BREW
fixed the high rpm breakup problem so anyone having similar symptoms on BREW or
Renesis engines using the EC2 should have that change too.
Tracy
Sent from my iPad
On Mar 21, 2012, at 4:56 PM, Mark Steitle <msteitle@gmail.com> wrote:
> Tracy,
>
> OUCH, that hurts! OK, here's the rest of the story. I've changed my
> intake manifold and changed injector sizes, so I'm back to the tuning
> phase. The B controller won't run right now as I haven't copied A to
> B yet. I'll have to do that before I can try the B controller.
> Thanks for reminding me that I typically do things the hard way.
>
> Mark
>
> On 3/21/12, Tracy <rwstracy@gmail.com> wrote:
>> Trying the B controller should always be the FIRST thing to try since it is
>> the easiest. This needs to be ingrained in all EC2/3 users mental (or
>> preferably written) engine failure check list. Everything including the
>> coil & injector drivers are swapped out when selecting B controller. Based
>> on the number of time I have asked if the B controller was tried when called
>> about an engine anomally I have concluded that very few builders are even
>> aware it it there : ).
>>
>> Tracy
>>
>> Sent from my iPad
>>
>> On Mar 21, 2012, at 3:58 PM, Mark Steitle <msteitle@gmail.com> wrote:
>>
>>> I have been chasing a problem with my p-port 3-rotor where the #1
>>> rotor cuts out at around 3800 rpm, but comes back at around 5000 rpm.
>>> When this happens, I can hear a change in the exhaust, and I see the
>>> EGT on #1 drop way down to around 500*, so that's how I determined
>>> that it was the #1 rotor. The other two rotors continue to run
>>> normally.
>>>
>>> I have tried swapping coils, replacing the #1 rotor's plugs & coil
>>> wires, and swapping injectors. I have not tried the B controller, but
>>> that sounds like what I should try next. My suspicion is there may be
>>> a defective coil driver circuit in the EC-2. I have borrowed another
>>> 20B EC-2 to try, but won't be able to do the swap until this coming
>>> weekend.
>>>
>>> Since things have been so quiet on the list, I thought I would post
>>> this strange problem and see what suggestions others may have.
>>>
>>> Mark S.
Mark,
Cannot quite make out exactly what you have done to your intake but it appears you may have
done away with the slide throttle and added traditional throttle bodies with primary injectors
after the throttle plates and secondary injectors before the throttle plates ??.............I am sure
you will fill us all in if that is not correct (with more detailed photos).................<:)
Kelly Troyer
Dyke Delta_"Eventually"
13B_RD1C_EC2_EM2
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