Vince Frazier
Joined: 10 Jan 2006 Posts: 132
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Posted: Tue Mar 30, 2010 6:11 am Post subject: hot cylinder cures |
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Kelly,
Great catch. Thanks for reminding me. I'll add that tip to the web page.
I've caught that on several new RVs and it's really easy to fix. So easy, that I neglected to even list it on the web page.
The easiest way to fix this is to simply remove the screw holding the baffle to the cylinder, take a regular washer and poke it in between the baffle and the front face of the #2 cylinder then put the screw back in the baffle to hold it in place. Do the same for the #3 rear face (or #5 on a 6 clylinder). Go fly and note the immediate temperature drop.
Thx,
Vince
SNIP From: Kelly McMullen <kellym(at)aviating.com>
Subject: Re: baffle sealing and hot cylinder cures
Be very careful what you seal up. #2 and #3 cylinders MUST have air on the intake port side, which is the side against the baffles. You need a minimum 1/8" gap between cylinder head and baffle there, probably 3/16 would be better. Lycoming does not cast any fins on the cylinder head on the intake port side. If you seal that, your cylinder will run 40-50 degrees hotter. It is a well known issue with Lycoming engines.
Kelly
A&P/IA
On 3/29/2010 7:08 AM, Frazier, Vincent A wrote:
Quote: | SNIP Regarding the requirement for sealing compound (silicon?) around
the baffle-to-engine
areas, what is the recommendation here? Is sealant absolutely necessary?
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Quote: | FWIW, a very often overlooked, LARGE air leak occurs at the bottom aft
edge of
the rear cylinders where they meet the case. There is often a huge, very hard to see hole there. Stick a flashlight back under and behind the cylinders and shine it up and forward. I'll bet you find a huge hole there. If nothing else, plug those! IMHO, this is a possible reason that many rear cylinders are unnecessarily hot.
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_________________ Vince Frazier
3965 Caborn Road
Mount Vernon, IN 47620
812-464-1839 work
812-985-7309 home
F-1H Rocket, N540VF
http://vincesrocket.com/ |
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