Cowl bottom lip

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Re: Cowl bottom lip

Post by 6643 »

Victor G » Tue May 17, 2005 3:09 pm

You have a couple choices with your exhaust stacks.

Leave them alone.

Recut the stacks with the proper slant as they are attached now.

Or, swap them side to side. Problem here is, as mentioned above is that they may not come out in the exact same spot and will rub on the side of the cowling, meaning more material removed from the holes in the cowling or try and (gulp) re-bend them(good luck)

The cowling doubler should be riveted in. Not something you would remove and re-install on a regular basis.
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Re: Cowl bottom lip

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Michel Charette » Tue May 17, 2005 9:06 pm

Victor, about the temperature graphs, I was mistaken, they were actually for the installation of intake baffles (winter kit).

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Re: Cowl bottom lip

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Victor G » Tue May 17, 2005 10:15 pm

Michel,

I could see where the temp graphs would be for the inlet covering. As I recall you are somewhere in the vicinity of Montreal? The last time I was there, it was -39 degrees. Wayyyyyy cold (Jan of 1989 perhaps?, memory foggy)

Dave,
I checked the two STC's I have for 0-200 installs, both the Gary Rice out of TX and the Lucas/Emmet (1999 version)(which I believe Randy Thompson now has this STC, have to get with him on the latest version) require a lower cowling doubler.
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Re: Cowl bottom lip

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Randy Thompson » Tue May 17, 2005 10:32 pm

My STC requires the cowling doubler and a blast tube on the oil screen.
Randy

A&P IA. Holder of STC for O-200A's in 120, 140 & 140A's. Engine overhauls on C-85's ,C-85's with O-200 crankshaft, C-90's and O-200A's
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Re: Cowl bottom lip

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NC76220 » Tue May 17, 2005 10:56 pm

My 1946 140, with C-85 is one cold blooded beast, it seems for my New England climate to be somewhat over cooled. Perhaps that is why the 1947 version has a more tightly cowled shape, with a smaller outlet hole below the cowl.

If I had a '47 or later bird, I would be looking for a set of Ser Vair cowl flaps. That would give better cooling when hot and less drag when cruising.

The modificatins to Michael's ship look like they may be designed to close the hole a bit and offer less drag. In the USA these modifications would mostly likely be illegal. My advice in the near term would be to return the cowl to its original configuration.

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Re: Cowl bottom lip

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Dave Z cf-eku » Wed May 18, 2005 3:22 am

I think you are talkin about the seaplane cooling lip, which mine still has. My 140 was originally on floats, two weeks out of Kansas for a few years. I found that my oil temp was a little on the low side, so i since removed about half the size of it w/ a cut-off wheel. Look in the parts book under options, I think you'll find it thar...
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Re: Cowl bottom lip

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Michel Charette » Wed May 18, 2005 8:14 am

Hmmm, perhaps Dave! I thought they were standard issue... What I'd like to see is a picture of a standard 1948 C-140 cowling opening !

And yes Victor, it can get bloody cold at times near Montreal but that does not prevent us from having temps in the high 90s in summer... yep, large temperature swings. You'd be surprised to see how the temperature can vary sometimes within 24 hours ! But we get used to it.

While I was searching for these temp graphs I also read the exhaust STC papers. There is also mention of the blast tube on the oil screen (it's there) and the doubler. If you look at the picture carefully, you'll see it, right between the aluminum cowling extension or lip and the cowling itself. Next time I get to the a/c, I'll take detailed pictures to show you.

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Re: Cowl bottom lip

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Randy Thompson » Wed May 18, 2005 9:11 am

I flew a Cessna 182 from California to Montreal for Expo 67. It must have been a warm time of year as I don't recall severe cold.

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Re: Cowl bottom lip

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David Sbur » Wed May 18, 2005 10:32 am

Randy,

When your 0-200 STC was the Lucas/Emmett STC did it require the lower cowl lip? Since mine doesn't have one and shows no signs of ever having one I better find out. Part number 0452248, right? My 337 shows it was installed as per Lucas/Emmett STC revision 5/11/81 yet I see no signs of it and there is no recorded accidents/damage to the lower cowling in the logs. I do know that the parts book show that this is installed in serial numbers 14365 and up, 140 models only, I'm a 140, serial numbr 8748, an obvious conflict of information between Cessna and the STC (OK, I'm grasping at straws maybe...).

Regardless, my engine runs very cool, presumably because of the old style lower cowl design.

My 337 shows an install date for the 0-200 and it's related stuff of 7/24/86. I do have a blast tube installed for both alternator and oil screen housing.

Dave Sbur/Vancouver WA
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Re: Cowl bottom lip

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Randy Thompson » Wed May 18, 2005 10:44 am

The cowling doubler, part number 0452208, was required since the original STC was drawn in 1967. Over the years different cowls have been interchanged. The important part is that the lip be there for cooling. I have seen them in many shapes and sizes depending on the cowl in service. That part number was for one of the two or three different cowlings.

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