Cowling vents and heat shields

So after melting various bits and bobs in the engine bay I finally installed some vents to vent the hot air after shutdown. I have not painted them yet but I think they look ok.

I was going to go to the trouble of sinking them in the cowling flush and so on but thought I'd trial them and maybe one day do that or probably just paint them first and fly till all the bugs are sorted. They are just a vent I bought on ebay, plastic and screwed onto the cowling. I have flown about 4 hours with these on and have noticed no change in engine temps during flight but after shut down, if you hold your hand over the vent, you can feel the hot air venting. This makes me smile.

Before I added these vents I had lots of trouble. I don't know if this caused the MGL RDAC to fail but I guess I'll never know.

I have also added some very crude looking (at this stage) heat shield over the engine mounts and trigger modules.

The heat shields are just made with some 6061 scrap I had and stainless zip ties and the insulation is a sticky backed  sheet that I have just stuck on and crudely moulded onto the accessory plate. I have also double wrapped the exhausts with two layers of exhaust wrap now too.  Since doing these small things my engine mounts have not needed changing and they seem to have stopped compressing even after the shortest of flights.

This pic shows the near new engine mounts after about 4 x hours flight. They had melted and crushed up and the pin was rubbing badly on the accessory plate. You can feel it in flight when they have worn or melted down as the engine begins to vibrate badly telling you that's the end of flying for that day mister.  Oh don't worry about the horrible brown leaks down the lower engine block, it's not oil , it's permatex from the initial engine build :)

 A vain attempt to add a washer or two to keep them tight, you can see how much the back one has compressed so I fitted a new front rubber and some washers to try and limp me through another flight.

Probably hard to see but the pin was rubbing on the accessory plate. New mount time again.

An indicator of how much it sagged as the prop rubbed on the cowling and scratched the paint,,, wasn't happy at all.


These lower three pics show the trigger modules and how much they had swollen up like balloons due to the heat from the turbo after shutdown, I assume, as inflight they have air running over them. I expect it was just the radiant heat when turned off cooking them or maybe in flight who knows. All I know is that since fitting the shield over the trigger modules they have stopped swelling. Both the top and bottom modules are swollen like this now but they aren't getting worse thankfully.  I emailed tech support early in the piece to ask about modules swelling up and was told I was the only one they had seen this happen to. As usual I guess I have done something wrong and not followed the instructions carefully enough. Anyway, it's fixed now. I will probably order 2 x new modules and another complete set of engine mounts and fit them so that now with the shielding in place the components should live long and happy lives in my cowling with the vents on the roof.