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Need opinions - insulation wrap in engine bay

SteveR

Active Member
I'd like to get thoughts on the pictures below. This is 2,000 degree insulation wrapped around exhaust and an oil cooler tube. My concern is that this will be a fire hazard as the insulation gets coated in oil over time.

48748877907_348d4d06c9_b.jpg


48748878102_839054cf8e_b.jpg
 
This is from Vetterman's website. It may not directly answer your question but it's worth considering if you are unsure about the wrap. I don't know what your exhaust is constructed from and I am definitely NOT an engineer but take the advice from trusted sources seriously.

"Any material on the exhaust will shorten it's life and failure will occur. We are using air cooled engines and one the best heat sinks on the engine is the exhaust system. The mass air flow comes in and is forced down and around the cooling fins and then is directed over the exhaust system and then exited out the bottom. If the exhaust is covered it cannot aid in the cooling process. Our tests show that any type of wrap on the exhaust makes both the cylinder head and exhaust temperature run higher. The stainless steel used (type 321) will degrade if the surface temperature is over 1250 degrees F. We also did not find a power increase of any kind by wrapping the exhaust"

Regards,
David
 
concur

worst placement of 'insulation' is around the exhaust -- it will shorten life [constant temperature swings means precipitation of moisture, retention of heat, etc.], makes visual inspection essentially impossible... a pinhole through the pipe into the wrap and what do you have??? - a mess, if you're lucky.
Vetterman's thoughts are 'right on' -- use the airflow to cool.
 
Are Those Plastic Zip Ties????

Wrapped around an exhaust pipe? If so, I'd have a verrrrry careful inspection done of the entire aircraft. They're likely to be other surprises.
Terry, CFI
RV9A N323TP
 
A lot of LongEZ flyers used wrap around the exhaust pipe to "help" with the CHT since the cooling in most EZs is updraft. The results WERE a shortened life on the stainless or other exhaust material, mine included. In an EZ anything that broke and got out of the cowl went thru the prop!! Wrap for that service presented a whole new level of inspection in that aircraft. The good news was that a cracked exhaust usually stayed in the cowl held by the wrap and wire until inspection revealed the exhaust leak . Exhaust Wrap not a good idea.
 
Aside from the points already made about this being a very bad idea, I have to laugh a bit at the PLASTIC tie-wraps used on the exhaust insulation...
 
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