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  #1  
Old 03-01-2014, 05:39 AM
dinowal dinowal is offline
 
Join Date: Dec 2011
Location: TWIN WATERS, Queensland, AUSTRALIA
Posts: 89
Default Cooling Duct query

Today I managed to get the cooling duct fitted & clecoed in the cowl bottom, but it is VERY close to the tappet cover on cylinder #4, less than1/8" in one spot. I don't know how far the engine moves on it's mount, but it would not have to go far to foul & perhaps wear away the duct. Should I worry?, - has anyone had a similar situation? Thanks for any thoughts, ....Cheers, DEAN..
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  #2  
Old 03-01-2014, 07:01 AM
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engineerofsorts engineerofsorts is offline
 
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Location: Austin, Texas
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Quote:
Originally Posted by dinowal View Post
Today I managed to get the cooling duct fitted & clecoed in the cowl bottom, but it is VERY close to the tappet cover on cylinder #4, less than1/8" in one spot. I don't know how far the engine moves on it's mount, but it would not have to go far to foul & perhaps wear away the duct. Should I worry?, - has anyone had a similar situation? Thanks for any thoughts, ....Cheers, DEAN..
Many of us have had a similar problem. The common solution is to cut a hole in the duct in the interfering region and glass a dimple into the area to give a more "comfortable" clearance. I'll let others define "comfortable for them. Mine comfort level was probably > 3/8".
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  #3  
Old 03-01-2014, 10:47 AM
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rvbuilder2002 rvbuilder2002 is offline
 
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An 1/8 is more than enough clearance at the #4 cyl rocker cover.
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  #4  
Old 03-01-2014, 03:29 PM
dinowal dinowal is offline
 
Join Date: Dec 2011
Location: TWIN WATERS, Queensland, AUSTRALIA
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Thanks for your prompt replies, gents - it is somewhat reassuring to know that others have had the same problem! As I have not glassed in the duct yet I think I will go ahead & make a " blister" to give more clearance, - it will give me another thing NOT to worry about when engine is started.. Cheers, DEAN..
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  #5  
Old 03-02-2014, 07:13 AM
rgmwa rgmwa is offline
 
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Location: Perth, Western Australia
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FWIW, I did the same to create more clearance.
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  #6  
Old 03-02-2014, 10:15 AM
RFSchaller RFSchaller is offline
 
Join Date: Oct 2010
Location: Phoenix, AZ
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Don't make the mistake I did. I clecoed the duct and glassed it without putting it back on the fuselage thinking the clenches would keep everything in place. It shifted just enough to not fit and I ended up having to redo it.
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  #7  
Old 03-02-2014, 03:12 PM
dinowal dinowal is offline
 
Join Date: Dec 2011
Location: TWIN WATERS, Queensland, AUSTRALIA
Posts: 89
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Thanks for that warning, - I have successfully made 'blisters' & given more room for cylinder heads 2 & 4. I Will be sure to reinstall cowls after fibreglassing while resin hardens... Cheers, DEAN...
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