Heat shield on top of cowl

[Bill.Peyton]

Has anyone used heat shield on the top cowl. Now that I have run the engine on the ground a few times I've noticed how hot the top of the cowl gets. I wonder if putting some reflective self adhesive shield may help

 

[N15JB]

I did put heat shield on the lower cowl where the exhaust comes close to the cowl, but none on the upper. After 200 hrs the glass and paint both look like new.

Jim Berry
RV-10

 

[DakotaHawk]

Cylinder Head Temps are going to be 350F or less just before shutting down the engine. You can expect the upper cowl to get hot, but never hotter than 350F. On the other hand, your in-flight EGT can be as high as 1500F. Although 350F may be hot to you, it's nothing near the EGT temps where you really need the reflective heat shield.

 

[Wayne Gillispie]

My top cowl is fine. Part of my lower cowl heat shield came loose. I would definitely not want a piece in that higher velocity air blocking cooling airflow. I always open oil door after shutdown.

 

[Bill.Peyton]

Thanks guys!

 

[DanH]

Bill, if you'll seal and paint for a slick finish the Vans self-adhesive aluminum foil sticks well. Work it with a soft plastic squeegee for maximum adhesion.

The shiny aluminum is a reflector for radiated heat. An insulator like fiberfrax slows conducted heat. A combination is the most effective approach. For example, here are fiberfrax strips which shadow the pipes, under self-adhesive aluminum.

As for the upper cowl, if you have a plenum cover it already intercepts radiated heat from the engine. If not, some aluminum foil may help. Air temperatures in the upper cowl reach the low 200's after shutdown, which should not hurt your cowl.

 

[vfrazier]

We have a similar insulated foil product which works well, along with several others that we like.

Insulation products

For a tidy installation, we recommend sealing the edges of the heat shield mat with RTV (red silicone or similar) or Proseal (use the baggie technique). This will look nice and help prevent any edges from coming loose, particularly if your cowl isn't as smooth and shiny as Dan's very nice cowl.

I have not heard of anyone having heat problems with the upper cowl. It does get quite warm, but not enough to harm anything.

 

[artrose]

Yes. I was getting some paint blistering on the upper cowl and I installed a sheet of lightweight self adhesive foil back automotive heat shield. Quick, easy, cheap, and works great.