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  #1  
Old 06-07-2020, 07:12 PM
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werxcv01 werxcv01 is offline
 
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Default O-360 RV-8 cylinder fins covered

Working on the condition inspection with an I/A he commented about the orange rubber wrapped around each cylinder. I bought this flying -8 last year and am still learning about it, even though I was a partner in a -6A for 10 years, also bought as a flying aircraft. This -8 has an O-360 and fixed pitch prop and an aluminum plenum. Anyone familiar with this wrap? It appears to cover from the 2 o?clock to 10 o?clock positions on the inner fins and from the 3 o?clock to 9 o?clock positions on the outer fins, with the top of the fins uncovered.
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  #2  
Old 06-07-2020, 07:35 PM
noelf noelf is offline
 
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What are the CHTs? Is each cylinder instrumented?
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  #3  
Old 06-07-2020, 08:08 PM
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CHT’s seem normal, perhaps a bit lower than I saw in the -6A with an O320. Maybe 335-360. It has a 4 cylinder CHT/EGT gauge from Electronics International.
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  #4  
Old 06-07-2020, 08:33 PM
BillL BillL is offline
 
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My IO360M1b parallel valve is wrapped about that much. Wrapping the cylinders will make no difference to the CHT measurement or very little, but shifting the airflow will. It does not mean that nothing is happening, just not reflected in the CHT. Removing them completely might even increase the CHT due to increasing air demand by cylinders dropping plenum pressure, thereby lowering mass across the heads.

What engine is this, parallel or angle valve?
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  #5  
Old 06-07-2020, 08:57 PM
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Is it something like this?



https://www.kitplanes.com/so-youd-like-to-go-faster/
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  #6  
Old 06-08-2020, 05:53 AM
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werxcv01 werxcv01 is offline
 
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I believe it is a parallel valve engine.
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  #7  
Old 06-08-2020, 05:55 AM
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It does look very similar to the photo you posted, Ken.
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  #8  
Old 06-08-2020, 06:11 AM
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So the cylinders are wrapped, or the heads or wrapped, or both?

Pictures?
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  #9  
Old 06-08-2020, 06:50 AM
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Both cylinders and heads are wrapped. My original post did not use the correct terminology.
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  #10  
Old 06-08-2020, 08:26 AM
Marc Bourget Marc Bourget is offline
 
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I haven't seen this approach before and am confused (seriously- not kidding).

It doesn't "fit" with my prior experience.

What is the benefit from blocking cooling air access to the "top" of the cylinders??

Plenty of support in the NACA cooling papers that argue this approach increases cooling drag and lowers heat transfer - especially on the "bottom" of the cylinders.
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