> In the car, all the intake valves are open at something like 6500 RPM
> (maybe even lower.) My manifold emulates the stock manifold in this
> condition. Should work OK for the expected RPM operating range.
>
>         With a 2:85 PSRU, the max prop RPM will be 3157. As I understand
> it, this should not be a problem for a 72 inch prop.  You just have to
> pitch it correctly to absorb 243 HP at that RPM (at altitude.)
>
>         I'm planning to rig up a dyno using a big disk brake (and a lot of
> water) to find out how  many HP the engine is actually making.
>
> Bill Dube'
>
>
>
> At 07:18 PM 2/7/2006, you wrote:
>>Boy, Bill, what an intake manifold project.  If it should not turn out to
>>work as you desire - it will sure make a nice piece of artwork! Sorry,
>>couldn't resist it - I know nice artwork is not what you are looking for.
>>Looks like a lot of work has gone into it already.  Will eagerly await its
>>production and test results.
>>
>>I am still curious as to how you plan to get the engine close to 9000 with
>>the prop load.  One of the problems that typically happens is that a
>>manifold may be designed and may give great performance at say 9000 rpm in
>>a car engine.  Because they can shift gears and regulate the engine load,
>>which of course we can not do ..... unless....Aha! you plan on using  a
>>constant speed/variable pitch prop - don't you.
>>
>>At least my experience with a fix pitch prop is that due to the prop load
>>the engine simply won't get up into the rpm promise land that the intake
>>design would seem to promise.  My very first intake manifold was being
>>used by the rotary racers at the time and producing 280+ HP at untold rpms
>>- I tried it and the engine could simply not get past a 5500-6000 rpm
>>range.  I replaced it with an intake of longer, much smaller diameter
>>intakes and have now hit as high as 6800 rpm.
>>
>>In any case, hopefully your results will everything you aim for.  In any
>>case, it should provide us with an expert on carbon fiber intakes - that
>>in itself would be great 3lbs vs my 11lb intake would be great.
>>
>>Ed A
>>
>>Ed Anderson
>>Rv-6A N494BW Rotary Powered
>>Matthews, NC
>>eanderson@carolina.rr.com
>>----- Original Message ----- From: "Bill Dube" <william.p.dube@noaa.gov>
>>To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
>>Sent: Tuesday, February 07, 2006 8:49 PM
>>Subject: [FlyRotary] Six port bolt-on manfold progress (was: RX-8)
>>
>>
>>>The six port will supposedly make 248 HP 100% stock. This is at about
>>>9000 RPM, however. The four port does not make as much HP stock.
>>>
>>>I am working on a carbon fiber composite manifold for the 6 port that
>>>(hopefully) will emulate the stock manifold with all the valves open.
>>>CNC machining of the molds will commence the beginning of March. We CNC
>>>machined a foam test mold a few months ago. We did a test layup of the
>>>carbon fiber about a month ago.
>>>
>>>Attached is a picture of the CAD rendition of the six-port manifold. As
>>>you can see, it will use the stock throttle body, stock injectors, stock
>>>injector rails, and will be 100% bolt-on. Should weigh about 3 pounds.
>>>(Stock manifold weighs 22 pounds.)  High temperature epoxy will easily
>>>withstand 300 F. Back-of-the envelope calculation says the burst presure
>>>on the carbon fiber tubes should be well over 10,000 psi.
>>>
>>>     The goal is to make a lightweight manifold that will hug the top of
>>>the engine and will simply bolt on.
>>>
>>>     It is going slower than I would like, but I am working on it in my
>>>spare time and trying to keep the costs down.
>>>
>>>     Bill Dube'
>>>
>>>
>>>randy echtinaw wrote:
>>>
>>>>Gentlemen,
>>>>    I have the opportunity to purchase a 4 port or a 6 port RX-8
>>>>engine. I thought I wanted a 4 port because I thought it would be
>>>>easier to muffel. I just heard a "rumor" that the 4 port is junk and
>>>>go with the 6 port. I need 220-230 hp using the 2.85 PSRU, no turbo.
>>>>I would consider P-porting if absolutely necessary to get the HP.
>>>>Obviously, I know very little about engines and want to start with
>>>>the best I can get so, considering my needs which one do I want?
>>>>Thank you,
>>>>Randy
>>>>
>>>>--
>>>>Homepage:  http://www.flyrotary.com/
>>>>Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/
>>>
>>
>>
>>--------------------------------------------------------------------------------
>>
>>
>>>--
>>>Homepage:  http://www.flyrotary.com/
>>>Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/
>>
>>
>>
>>--
>>Homepage:  http://www.flyrotary.com/
>>Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/
>
>
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