Richard Connell
Well Known Member
Some people PMd and asked me to show some more pictures of my plenum.
I have a Barrett IO-540 with CAI, 9:1, showplanes cowl and a Hartzell 3 blade.
When I built my RV7 I never really enjoyed the fibreglass aspects of the build.
It wasn’t difficult, I just never warmed to it.
As the RV10 canopy loomed in my future I was quietly dreading it.
Anyway, after many many months (maybe even years) it was finally done, and I had learned some new skills in the process. Thats what its all about right?
So I decided to build some internal centre console tunnel parts as well which turned out better than I had expected.
So I thought Id try my hand at building a plenum for my engine.
Brief summary: I layed up the basic shape using the top of the cowl as a mold.
I then made some balsa/glass edges. Glued them all together and formed a solid plug that mimicked the final shape sitting on the engine.
In order to seal around the dipstick I formed a well in the top of the plenum.
I finished it up nicely with some 2k primer and topcoat then took a mold off it.
Finally I used a vacuum resin infusion process to pull a part from the mold.
It came out pretty good first go. A few minor flaws which were relatively easy to fix.
I had some larger intake rings machined - with rounded ridges to wear better long term. Floxed them into the cowl halves waxed.
Then made up some ducts from the rings to the plenum and attatched them to the plenum.
I 3d printed up a sleeve to attatch to the dipstick top which screws into the oil door well bottom.
Still need to join the rings to the duct with some sleeving. Its on the long list of minor jobs which seem to take a lot longer to get done once flying.
Id hate to think how much time I put into it, but if seems worth it now that its done, and I learnt a lot along the way.
The plane comfortably meets book values or a few Kts quicker.
I probably set my expectations too low for this plane TBH. My benchmark was equivalent performance to the 7 - I expected the 3 blade to hurt cruise performace.
Its much better than I expected.
I have a Barrett IO-540 with CAI, 9:1, showplanes cowl and a Hartzell 3 blade.
When I built my RV7 I never really enjoyed the fibreglass aspects of the build.
It wasn’t difficult, I just never warmed to it.
As the RV10 canopy loomed in my future I was quietly dreading it.
Anyway, after many many months (maybe even years) it was finally done, and I had learned some new skills in the process. Thats what its all about right?
So I decided to build some internal centre console tunnel parts as well which turned out better than I had expected.
So I thought Id try my hand at building a plenum for my engine.
Brief summary: I layed up the basic shape using the top of the cowl as a mold.
I then made some balsa/glass edges. Glued them all together and formed a solid plug that mimicked the final shape sitting on the engine.
In order to seal around the dipstick I formed a well in the top of the plenum.
I finished it up nicely with some 2k primer and topcoat then took a mold off it.
Finally I used a vacuum resin infusion process to pull a part from the mold.
It came out pretty good first go. A few minor flaws which were relatively easy to fix.
I had some larger intake rings machined - with rounded ridges to wear better long term. Floxed them into the cowl halves waxed.
Then made up some ducts from the rings to the plenum and attatched them to the plenum.
I 3d printed up a sleeve to attatch to the dipstick top which screws into the oil door well bottom.
Still need to join the rings to the duct with some sleeving. Its on the long list of minor jobs which seem to take a lot longer to get done once flying.
Id hate to think how much time I put into it, but if seems worth it now that its done, and I learnt a lot along the way.
The plane comfortably meets book values or a few Kts quicker.
I probably set my expectations too low for this plane TBH. My benchmark was equivalent performance to the 7 - I expected the 3 blade to hurt cruise performace.
Its much better than I expected.