Thanks
Thanks for all the nice comments. I'll try and answer some of the questions:
The only potential gotcha I see is the amount of air you're stealing at the back of #3. I think you'll find your oil is going to run pretty cool with that monster cooler. I have Van's standard cooler with a 4" SCAT in the same location as you do, and a 2" scat for cabin heat is taken off of my #4 baffle.
I agree and I can't tell you how many time I went back and forth on what to do here, but I finally just decided to build it and deal with it during testing. I figured I can always choke down the flow to the oil cooler if I need to but adding flow would be more difficult. The cabin heat scat can also be moved to behind #4 if necessary. I'll have to see how the cabin heat works also, since I have mufflers and am running them in series. More experimenting.
Did you lay up the top from the top of the cowl?
What cooler did you use and did you make the plenum for the oil cooler?
The only thing I see that could be an issue is the inlets being aluminum and mating with the glass. The engine moves and the cowl is fixed. Any insulator between the cowl and inlets?
Yes, I used the top of the cowl as a form to lay up the top of the plenum.
I used some non-reinforced silicone rubber to join the cowl rings to the diffuser. I've posted a link to a video below that shows how much movement the system can accept. I hope its enough.
I'd suggest cutting back the length of the aluminum intake diffusers and increasing the length of the silicone rubber. The engine case torque reaction is significant, and adding length to the silicone tube will reduce load on the aluminum parts. My intakes are glass reinforced urethane. Your unreinforced silicone should give a bit more, a plus.
Same or related issue...make sure you have at least 1/2" cowl clearance at those upper front corners. Your parallel valve heads are easier to package in this regard so it may not be an issue. My angle valve head offers less clearance to work with in the RV8 cowl. I thought it had enough clearance but it still bumps on start-up or rough running.
Dan, first off I want to say that a lot of this design was inspired by if not directly copied from your plenum. I've got a long ways to go to get to your level of craftsmanship and knowledge but it's something to strive for. Thanks for raising the bar.
You may be right about cutting the diffusers back some but right now I think the system should allow sufficient movement of the engine relative to the cowl. The non-reinforced silicone stretches fairly easily. How long it will last is another issue that I'll have to keep a close eye on. Here's a link to a video showing how much movement the system will accept easily.
http://www.youtube.com/watch?v=7WIbDXnEhjU
I have 1/2" of clearance all the way around between the plenum and the upper cowl.
Do you have also a 4" Scat on the exit side of the oil cooler.In the affirmative how far down did you carry the scat tube: between the exhaust pipe ?
No, right now the oil cooler has no exhaust ducting. If I find I need to choke the flow to the cooler, I'll probably make something that will allow me to choke the exhaust rather than the inlet.
Which oil cooler did you use, can you post a couple pictures that show that setup better please?
I have an Aero Classics 8000074 nine row cooler. I'll try and post some in a couple of days.
And, NO! I don't want to go into business making these. This was a ton of extra work. About 3/4 the way into this I was kicking myself for not just building to plans but the first things I made were the cowl rings so I was kind of committed.
Thanks again for the comments,
Chris