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1. 08:06 AM - Re: RV8 Cowl Exit Area (Applicable to RV8 Cowls delivered in 2000 or earlier) (Scott Clarkson)
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| Subject: | Re: RV8 Cowl Exit Area (Applicable to RV8 Cowls delivered in |
2000 or earlier)
--> RV8-List message posted by: "Scott Clarkson" <sclarkson@tellurian.net>
Since the topic of cowlings came up I figured I'd mention that I have a
brand new -8 cowling with vertical induction sitting here in Northern NJ if
anybody is interested. I received it before deciding to go with the Sam
James cowling. Someone semi-local and ordering a finish kit may want to
suspend the cowling and grab mine at a substantially reduced price. It's
the newer version (2 years old) by the way. Contact me off-list if
interested.
Scott Clarkson
N360SC (reserved)
do not archive
----- Original Message -----
From: "Esten Spears" <ewspears@comcast.net>
<rv8list@yahoogroups.com>
Subject: RV8-List: RV8 Cowl Exit Area (Applicable to RV8 Cowls delivered in
2000 or earlier)
> --> RV8-List message posted by: "Esten Spears" <ewspears@comcast.net>
>
> Long - Delete Now if not interested in RV8(A) Cooling Problems with early
Vans Cowl
>
> The following is an email exchange between myself and Gus Funnell at
Van's. It follows two separate phone calls to Vans that both times I was
assured there were no different RV8 Cowls;
>
> > > > On 14 Jun 04, at 14:38, Esten Spears wrote:
> > > >
> > > > > Gus,
> > > > > Attached are 3 photos;
> > > > > 80922Cowl Exten Measurement shows the lower cowl extension I
> > > > > received with my kit (80922) in April 99 (Sun n Fun) You can
> > > > > clearly see it has a 2" drop or extension on the lower cowl.
> > > > >
> > > > > Lower CowlExtension Measurement is a photo of Ray Parker's
> > > > > (Builder# 81078) Cowl that he received in July 01. You can
> > > > > clearly see it has a 3" drop or extension on the lower cowl.
> > > > >
> > > > > Lower Cowl is a photo of Ray's lower cowl which you can see a
> > > > > new extension has been grafted into it by the cowl vendor. It
> > > > > is very obvious when you see it in person and harder to see in
> > > > > the photo.
> > > > >
> > > > > The 3" extension has about 11sq. in. more exit area than the
> > > > > 2" extension. Under the worst conditions (Angle Valve Engine,
> > > > > NoseGear Obstruction, and HOT Climate) Even the 3" extension
> > > > > is marginal. I certainly don't want to use the 2" extension.
>
>
> > > ----- Original Message -----
> > > From: "Gus Funnell" <gusf@vansaircraft.com>
> > > To: "Esten Spears" <ewspears@comcast.net>
> > > Sent: Monday, June 14, 2004 6:51 PM
> > > Subject: Re: Different RV8A Cowl Extensions
> > >
> > >
> > > > It's true that we have changed the cowl since you received yours
> > > > (more than 5 years ago). The fact that we changed it does not
> > > > entitle you to a new one at no cost. You received the one that was
> > > > current at time of shipping, as did other RV-8/8A builders at that
> > > > time. If we had to ship new cowls because we improve the old ones,
> > > > that would act as a powerful disincentive to any kind of improvement
> > > > in our kits.
> > > >
> > > > Our RV-8A here has the old style, and it works OK, even in warmer
> > > > climates, though I would agree that an extended full power climb may
> > > > see elevated oil temps. As you are aware, many early 8 builders
> > > > installed louvres on the bottom of their cowls, or enlarged the
> > > > outlets to improve cooling, though this has not been necessary on
> > > > our 8A. So you may have no problem with the cowl you have in any
> > > > case.
>
>
> From: "Gus Funnell" <gusf@vansaircraft.com>
> To: "Esten Spears" <ewspears@comcast.net>
> Subject: Re: Different RV8A Cowl Extensions
>
>
> > On 15 Jun 04, at 0:16, Esten Spears wrote:
> >
> > > Gus,
> > > First off, Thanks for your prompt reply! I do have some issues
> > > with your
> > > response.
> > > 1) Why was I twice adamently told there were no different
> > > cowls and
> > > only after I sent photos you admitted to the cowl change?
> >
> > No-one here can remember this kind of thing. The vendor who
> > makes the cowls doesn't remember, because we have changed
> > vendors and he has only ever made one kind. When I measured our
> > 8A it is obvious that it was changed, but even now there is no-one
> > at Vans who could tell you exactly when the change occurred, and
> > since we did not change the part number there is no indication that
> > there was a change.
> >
> > > 2) The suggestion that I may have no problem anyway is not a
> > > good
> > > one since carving up or replacing the cowl after a fancy Imron paint
> > > job makes no sense. Also while your company 8A has made visits to
> > > warmer climates, it basically lives in cold rainy Oregon.
> >
> > Cold, rainy Oregon routinely gets up into the 90s in summer, and
> > what I have seen, flying it in Texas, Florida and Arizona in summer,
> > is that the oil temp will get up to 220 or so, the cylinder heads stay
> > under 400 all the time.
> >
> > > 3) Instead of just telling me my request is unreasonable, how
> > > about
> > > a suggestion to correct the problem that you do think is reasonable.
> > > ie. (Maybe Vans or your cowl vendor has a scrap cowl that has a good
> > > 3" drop exit on it, in which case you could just cut it out and I
> > > could graft it into my existing cowl or Maybe make me a special price
> > > on a lower cowl) Esten Spears
> > >
> > OK, my understanding was that you wanted a new cowl. We don't
> > have any scrap cowls. If we find problems with them when they
> > come in from the vendor, we send them back to be reworked; they
> > are too expensive to throw away.
> >
> > We could give a you a discounted price on a cowl. It would be $XXX
> > (normally $XXX), which is still a lot for a problem that may not exist.
> >
> > Gus
>
> Gus,
> Thanks for the offer and explanation but I've already updated it. See
> attached photo. Changing it to a 3" drop was a lot easier than getting my
> one piece canopy skirt to fit! When I think of all the headaches, time,
and
> money various builders have spent trying to get Angle Valve 8A's to cool
> properly with the 2" drop cowls it's a shame Van's Aircraft couldn't
> disseminate the info. I fully understand you not wanting to replace the 2"
> Drop Cowls. But a simple service info letter suggesting that if you are
> running an Angle Valve Engine in an 8A and have a 2" Drop Cowl, You might
> want to modify it to 3" Drop and give some instructions for doing it. It
> wouldn't cost Van's much and could save some builders a lot of grief.
> After doing some cooling air intake and exit measurements and
> calculations, I don't see why the cowl drop was ever set at 2". The
intake
> area is 41.25 sq. in. The exit area with a 2" Drop Cowl is 44.5 sq. in.
It
> is 55.5 sq. in. with a 3" Drop Cowl. All my education and experience tells
> me exit areas should be 1.5 to 2 times inlet area! To make matters worse;
An
> RV8A has a relatively clean entrance with the cowling ramps installed but
> has a terribly dirty and turbulent exit which tends to make the required
> exit even larger! From an cooling standpoint even the 3" drop exit is
> marginal but may be the best compromise considering drag.
> Esten Spears
>
> Do Not Archive
>
>
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