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Dave,
I had a similar problem with mine, and found that the throttle body I was
using (for 5.0 Ford) had a bypass built into it allowing air to go past the
closed throttle plate. I filled it with silicone to seal it up.
Steve Brooks
-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On
Behalf Of Ed Anderson
Sent: Tuesday, July 17, 2007 8:00 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Hi Idle RPM was : [FlyRotary] Re: The adventures of
Chris and Dave.. PART DEUX
David,
If you can not get the idle below 1800- 2000 rpm, then I would strongly
suspect an air leak. It does not take much of one, to let in enough air so
that your manifold pressure stays above 12-13 " Hg. At 16" H20 you are
making power. First, make certain your throttle plate is indeed closing
fully, make certain there are not any unnoticed openings/lines on the TB
that may be open. Then check for air leaks in the intake system from TB to
block.
Here is the method I use (there are undoubtedly others), I take a large
shop vac and tape it to the intake of the TB making it air tight with (of
course) duct tape. Get some soapy water or kids bubble blowing fluid and
then spread the liquid around all mating surfaces. TB to Mount, Mount to
intake manifold, any junctions in your intake and finally manifold to block,
around your injector mating surface with block or intake. Also spread some
around all bolts/nuts you may have plugging any part of the intake. If
there is an air leak the bubbles will show you where.
Good Luck
Ed
----- Original Message -----
From: "David Staten" <Dastaten@earthlink.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Tuesday, July 17, 2007 12:10 AM
Subject: [FlyRotary] Re: The adventures of Chris and Dave.. PART DEUX
> And the fun continues.
>
> The oil pan gaskets arrived from Atkins Rotary a few days ago, and we
> decided to do the big swap today. I had previously "sealed" the pan and
> CCI sandwich mount with a Permatex brand can of aviation grade liquid
> gasket. I was thinking I had simply made a a mistake in my method of
> applying it up until this point. We disconnected a few hoses, positioned
> the hoist and used my two covenient lifting points (one is on the front
> iron, between the alternator and the plug side, the other is a nut that
> backs up onto a RD1B mounting bolt. The nut is superfluos because the
> point it mates with the housing is threaded as well). As soon as we lifted
> the motor, and dropped the pan bolts, it was clear that this particular
> flavor of permatex was NOT UP TO THE TASK. The pan and plate separated
> under the force of gravity. No cling whatsoever.
>
> We scraped the remaining sealant with a putty knife, and then our
> fingernails. Cleaned out the pan, used WD40 first, then cleaned up all
> traces with a rag with a conveniently available solvent (93 octane).
> Placed the gaskets on, one at a time, used grey permatex for a new gasket
> material (I had previously bought it for this purpose, until i was
> practically GIVEN the other "bad" sealant by a local aviation parts house
> owner). Unfortunately had to drop the siphon tube as well, since we didnt
> have enough clearance to remove the plate without doing so. My oil pickup
> tube bolts have a sandwich spacer to extend the pickup, and the bolts were
> drilled and safety wired. Was a chore to reinstall in the close quarters
> we had, but it was accomplished. Reinstalled the 6 mm pan bolts, and got
> to re-safety wire 10 of those today. We refilled the oil with mineral and
> then restarted the engine.
>
> We were unable to improve/get slower than 2500 rpm and 16"mp, and we
> were making significant thrust. Just yesterday, before we changed the oil
> and re-did the pan, chris said he was gettin 12-1500 rpm and good idle,
> prior to some tuning runs. Leaning made it run rough, so the tuning
> appeared spot on. When we advanced the throttle we had some surging, and
> this corresponded with Chris saying he could only tune a part of the way
> due to heating. The surging is presumed to be caused by straddling an
> untuned area next to a tuned part of the mixture map. We played with
> trying to locate any air leaks that could account for our closed throttle
> excessive rpms. We may do some tweaking of the throttle cable interface
> and ensure we truly are closed. We also discovered we had a bigger oil
> leak than we originally suspected.
>
> I noted that we had a dry oil pan seam, but had oil dripping from the
> starter. Then I noticed oil was all over the inside of the flywheel chase.
> When we restarted, I was able to see oil coming from the spline shaft hole
> in the baseplate of the RD1-B. We have not noticed this before, but we do
> not believe it started just today. The oil line in is a stainless 1/8"
> hard line with AN4 fittings. The forward oil drain gets warm. In the past
> the aft oil drain and tubing did not. I did not check it today. I do not
> know if we are having a prob with excessive oil flow/pressure versus
> drainage capacity. Cant find the RD1-B manual, so have a request in to
> Tracy for electronic manual and also feedback on the RD1 before we de-mate
> it. May possibly have other small leaks associated with the hard line
> being misaligned, and i have some stainless braid AN4 I can put hose ends
> on and use for this purpose. Also possibly some leakage at the psru oil
> return fitting on the block, since that was not dabbed with thread sealant
> prior to runs. But steady oil flow from the spline shaft is unmistakeable.
> The shaft slings it all over the flywheel chase and into the air, where
> its coating the prop (and has been since day 1)
>
> Chris called tonight to mention that timing was something he was
> thinking of as a possible culprit. I agree that it may be a factor, but
> typically i thought timing "problems" resulted in degraded performance.
> Our problem is we are making too much power (and heat) in what should be a
> closed throttle condition. Any feedback on timing would be nice.
> PARTICULARLY ON HOW TO GET IN THERE WITH A TIMING LIGHT, since the prop is
> installed, and the timing marks are up close to the radiator.
>
> We are continuing to have an intermittent NOP indication on the EM2.
> Chris is going to re-terminate his connections on both ends to see if that
> makes a difference, before we junk the whole wire run.
>
> Thats all for now. Fire away with any and all feedback
> Dave
>
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