Cooling Plenum, Was: Re: Importance of good baffle seal
Posted: Sat Feb 18, 2012 9:26 am
Wayne you have brought to mind someting have been contemplating for a while and
that is building a proper sealed plenum for the cooling air.
I have seen a couple of pictures in the mags. that show something like this
where a complete box is formed around the engine in a way that mimics the baffle
enclosure but since it is assembled before the cowl top is put on you can be
sure that there are no uncontrolled air leaks. Of course you have to attach
flexible ducts from the cowl intakes to the plenum but that can be done.
What do you guys think of the idea? Given Wayne's story it sounds like a good
way to design out the doubts & problems of fitting & trimming baffle rubbers and
wondering if that is why the engine runs hot.
The units I have seen were fibreglass and I believe blow molded in polyethelyne,
of course blow mold tooling would be pricy......
Anyway, just wanted to toss the idea around & see what you think.
Dave
"Wayne G. O'Shea" wrote:
David A. Ricker
Fall River, Nova Scotia
Canada
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that is building a proper sealed plenum for the cooling air.
I have seen a couple of pictures in the mags. that show something like this
where a complete box is formed around the engine in a way that mimics the baffle
enclosure but since it is assembled before the cowl top is put on you can be
sure that there are no uncontrolled air leaks. Of course you have to attach
flexible ducts from the cowl intakes to the plenum but that can be done.
What do you guys think of the idea? Given Wayne's story it sounds like a good
way to design out the doubts & problems of fitting & trimming baffle rubbers and
wondering if that is why the engine runs hot.
The units I have seen were fibreglass and I believe blow molded in polyethelyne,
of course blow mold tooling would be pricy......
Anyway, just wanted to toss the idea around & see what you think.
Dave
"Wayne G. O'Shea" wrote:
--FYI for those guys complaining of high CHT's you might want to have a good
look. Have a local guy here with an O-320 in a Luscombe that has been
removed and shoved engine back up the overhaulers @$$ 3 or 4 times in the
last year and a half.... telling him he did a shit job on the overhaul. Case
has made trips to ECI, cylinders have been redone twice etc and still
running high. One of our chapter members said to him last week.."you really
should take that ratty baffle seal off and put some new stuff on...it sure
might help". When he finally gave in and listened the CHT's dropped ONE
HUNDRED!!! degrees F! Makes you wonder if any of the nine or ten thousand
dollars in extra work and a year of aircraft downtime (and the fun of
pulling a motor on and off using a tripod on the beach!!) and tinkering
actually did anything.
Cheers,
Wayne
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David A. Ricker
Fall River, Nova Scotia
Canada
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