Paint is over rated
Is the standard A curve sufficient? I have an IO-360 with 9:1 pistons and an Av star FI system. Maybe you haven?t flown yours yet, but if you have, please let me know the advantages of the EI Comander.
Thanks
What is the advantage of a CS prop for racing? Or did you add it for a different reason? I would have thought that for a race there is only one speed range...balls out!
I did not do it for racing. I expect to loose 2-3 knots top speed. That been said, One of the things that killed my speed around the track was exiting the pylons with low RPMs. The RPM would drop and i would loose a lot of speed. It would take some time to build the RPMs back up. and by then I was in another turn. So my time around the track may be slightly afected now that the RPM would remain constant.
Not sure I will be racing at Reno with this plane any more. The plane just gets beat up and a non-boosted or non-nitrous RV in the sport class is not guaranteed a spot in the field of 36 now.
I have mixed feelings about this convertion. However, All this may go away once I satrt flying. TBD at this moment.
I think you will love the constant speed prop!
Skylor
Very interesting build out. What's the empty/WT.
Cheers, Hans
I admire honesty and that's a porky plane ya have there
Hans
The first RV4 I owned weighed in at 1,080 pounds with an O-360 and Hartzell prop. And it was bare bones. And it went like snot. Of the three (3) RV's I've owned, it was my favorite.
Don't sweat the empty weight.
Hans, I came out at 1,013lb and CG of 69.9 inches. I have not flown much but it does not fell as maneuverable. I know you are big into light and simple. Me too. Not sure this was the right thing to do yet. Will report out once I get some data.
Time to start wrapping the cylinders. Mark the shape of your piece on the plastic, put RTV on one plastic sheet, put the fiberglass on top, put another sheet of plastic on top, squeegee it evenly, cut it as required, pull one side of the plastic and stick it on the engine. Leave the other side of plastic on until the RTV dries. That leaves a nice finish on the outside.
I’m curious about this too. Will you use standard inter-cylinder baffle material, or something else to seal the gaps between cylinders? I assume that it will seal the fin areas better than aluminum sheet, but how is it going to hold up in use? When it comes time to do cylinder work will it come off easily? Has this been done before, or are you blazing a new trail? Good luck. Cant wait to see the final installation.
It doesn’t look like the cylinder base fins are getting any cooling at all. If this is the case, why don’t we just point cooling airflow at the cylinder head only? Reduce cooling inlet and exit accordingly.
No concerns with the heat exposure to the fiberglas at close proximity?
I've had the idea that epoxy-impregnated fiberglass gets wonky above 200F.
I've had the idea that epoxy-impregnated fiberglass gets wonky above 200F.
Thanks Dan, that means a lot. I remember my Aerospace professor saying...."become the air molecule, flow through/around the part" or something to that effect.Those are very some shapely diffusers. I bow to Axel the Artisan!
Nice work! Will engine movement inside the cowl be any problem?
This is a mold. Not the finished part. The final part will have neoprene hose to tie up the cowl ring to the diffuser.
Have you thought about doing it like Dan did and making a flexible duct/diffuser unit? https://vansairforce.net/community/showthread.php?t=43391
I like what I see.
Only comment that I can think of is that Dave Anders has an "Angle Valve" engine. The angle valve engines have better oil flow to the valves and if memory serves me correctly, there are oil squirters on the bottom of the pistons so there should be more heat removed from the cylinders in the oil than what most of us have on the parallel valve engines.
Watching the temperatures on the first few test flights will help make sure that enough heat is removed from the engine.
Please post your test data when flying this setup.
And - - the angle valve has intake induced swirl that yields faster combustion burn needing less spark advance and lower heat rejection. The higher fin density is far superior to the parallel valve. Thus, the angle valve cooling air can be throttled down a lot more than a parallel valve and still have cooler internals.
Some familiar looking stuff there Axel - -looking cooler and faster . . . .
Axel, if you are using a felt prop seal, I have some input on that. And and pictures.