Lynn, I have no idea what a homogenizing muffler is. Explanation?
The homoginizing muffler is a big can tight against the engine, with the short tubes for headers. A large diameter tube through the end of the can has hundreds of holes for the gasses to escape into the tube, then out of the muffler and into the down pipe. Next to the engine it must be very strong and made of Incolnel or Stainless to stay together. The header pipes have no tuned length, and back pressure may cost HP. The can dumps lots of heat under the cowl.
Since I'm not modifying the port timing, changing to earlier rotors with
counter weights, I think the thing to do is to turbo it.
Early rotors would be lower compression than the Renesis rotors at 10:1. So turbocharging would be less a problem. Use 3MM apex seals in ceramic. The Renesis rotors have tapered side seals (I am told) Never seen one myself. The apex seals and grooves are short as they never cross a port opening. Both intake and exhaust ports are in the irons.
I like your
idea of a huge compressor with no waste gate. A few pounds of boost
with a large volume. Seems Mazdatrix has abandoned the turbos for a
supercharger that does just that. 6 lbs of boost with the low end model
and 12 lbs for the bigger. Any idea who makes a turbo like that? Or a
supercharger that is small and will hold up to continuous use?
My thinking is that a poorly thought out turbo installation can produce low boost
for several reasons.
One would be a compressor wheel too large. Another would be the turbine wheel too small.
Fine. So it only makes 3 pounds or 6 pounds close to sea level, and 1 or 2 pounds at 8,000 feet. Perfect.
No muffler, or very little muffling required. No waste gate required. Lycoming sea level HP at 8,000 feet where the Lycoming has only 117-145 HP. By by Lycoming powered friends
Superchargers can have very long lives. Big GM 2 cycle diesels have the big 671 superchargers bolted tight to the blocks on millions of engines, running for billions of hours around the world.
Lynn, My water at 185 f and oil at 205 f was at WOT at 8000ft, prop at
2450 and engine at 6980RPM. Yeah, the oil is high. I may be having the
situation that Tracy spoke of. Back pressure inside the cowl due to the
radiator having less restriction than the oil cooler. At high speed,
the cowl flaps don't help. Better than it was though. When I back off
on the throttle, it drops fast, although I don't remember how much.
That oil temp is costing you HP. With better cooling you might need more prop. How nice. You can tell you are close on rejection rate when the temp comes down with a bit less throttle. I use 3 40 row Setrab coolers and that is not enough on a scalding hot day. The driver just short shifts to bring the temps down. Like shifting at 9,200 RPM instead of 9,600 RPM. Then if you are back under 180 you can do a lap shifting at 9,600 again with no problem.
If the oil temp goes over 200 and just stays there or only comes down after a number of minutes at a lower throttle setting, then you are not close, on rejection rate and must make a change. OIl temps above 160 are costing HP.
Lynn E. Hanover
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