Message-Id: <5.2.0.9.0.20040505204138.024cdd70@mail.teleport.com>
Date: Wed, 05 May 2004 20:53:52 -0700
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
From: Michael McGee <jmpcrftr@teleport.com>
Subject: Re: [FlyRotary] Re: Coolant Pressure Gauge
In-Reply-To: <list-3208098@logan.com>
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I have not had my hands on a Renesis engine but the photos I've seen of the 
Renesis front side plate looks very similar to the 13B.  Now, the front 
COVER is very different.  The water pump housing on the Renesis is part of 
the front cover casting.  This is a long way of saying I don't know yet.

I expect that we will be eventually casting adapter plates for both if they 
are different.  We plan on eventually having a plate that will also work on 
Lycoming conical and Dynafocal II mounts as well.  So, the answer to your 
question is eventually yes.  It will likely be a year before you see one 
for a Renesis.  We will need to have a few flying and most likely a few 
revisions before we expand beyond the existing pool of 13B engines.

How far along are you on your -7A?

Mike


At 20:23 2004-05-05, you wrote:
>Mike
>
>Is the dynafocal mount adapter you are developing something that would 
>work with a Renisis on my RV-7A?
>
>Kelsey Jewett
>On May 5, 2004, at 2:03 PM, Michael McGee wrote:
>
>>The alternator speed isn't a problem, it doesn't care how fast you spin 
>>it (unless you have an alternator that is way out of balance).
>>On my RV-4 with Lycoming engine the alternator is over-driven about 4:1, 
>>I have the 2-1/2 inch stock alternator pulley, the crank/ring gear pulley 
>>is about 10" diameter so the alternator will see 10,000 at cruise.  This 
>>is typical of most Lycoming installations on experimentals and is not a 
>>problem on thousands of planes.
>>
>>My e-shaft pulley is 4-1/2 inches dia.  I think it is a stock pulley as 
>>the timing pointer is at the edge of the pulley.  That makes the 
>>alternator over-driven at 1.8:1.  Using a 6000 rpm cruise with my RD-1C 
>>that makes the alternator spin at 10,800.  Close enough.
>>
>>There are enough Lyc drivers that were uncomfortable with this that 
>>someone makes a 4" pulley for the alternator.  Aircraft Spruce 02-03 
>>catalog page 245, p/n 07-06828 $48.95.  (A waste o' money except for the 
>>feel good factor.  If you'll accept MY explanation I'll accept your 48.95 
>>and SAVE YOU shipping costs!
>>P-)
>>
>>Regarding water pump speed, I've been working on this for a few weeks 
>>with my 13B dynafocal adaptor.  I've mostly come to the conclusion (yet 
>>open to more data or ideas) that the factory pump and pulley are sized to 
>>provide the needed flow capacity at any given engine speed at the 
>>horsepower levels we are running at.  So, to make it easy I'm sticking 
>>with the stock pump at the stock pulley ratio.
>>
>>Mike
>>Mike McGee, RV-4 N996RV, O320-E2G, Hillsboro, OR
>>13B in gestation mode, RD-1C, EC-2
>>
>>At 12:06 2004-05-05, you wrote:
>>>Well, that's interesting.  This reminds me of a nagging question I have 
>>>had, but haven't asked.
>>>
>>>I was curious about the need to go to a smaller crank pulley to slow 
>>>down the water pump and alternators.
>>> From memory, the crank pulley is about 5-1/2", the alternator pulleys 
>>> are about 2-1/2", and the water pump
>>>pulley is about 4" diameter.
>>>
>>>So, running an RD-2C (2.85 ratio), the alternators will be turning about 
>>>20k during climb-out and the wp will be turning
>>>about 10K rpm.  That seems too fast to me.  I could probably find larger 
>>>pulleys for the alternators, but
>>>then there's the water pump pulley.  Your unplanned experiment would 
>>>suggest that we can run the wp slower
>>>and still cool adequately.
>>>
>>>This brings me to a second option.  I think a simpler approach would be 
>>>to reduce the size of the crank pulley.
>>>The problem is that I haven't found a multi-V reducing pulley at any of 
>>>the after-market suppliers.  I really don't
>>>want to change over all the multi-V pulleys to single V pulleys, but 
>>>that is one option.
>>>
>>>Another solution might be to find a smaller pulley from another vehicle 
>>>and adapt it to fit the rotary.  If that doesn't
>>>work, I could have one made.
>>>
>>>So, am I worrying about nothing, or is this a real problem?
>>>
>>>Mark
>>
>>
>>
>>>>  Homepage:  http://www.flyrotary.com/
>>>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
>
>
>>>  Homepage:  http://www.flyrotary.com/
>>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html