Originally Posted by Glowgeek

I'm curious what you fellas think about how using crankcase pressure to create tank pressure will affect engine lube. If I was using max tank pressure and regulating I wouldn't worry because of low flow, but I'm not. Whether I use the solenoid as a programmable air bleed or just use an open Tee fitting to bleed off pressure there will be a lot of waste air travelling out of the engine. I fear it will carry away the needed oil mist.

Here's the 220 back plate modded for using check valves. They both leak but that's not critical. Once installed I realized I may not need both checks, just one for checked air inlet. If I don't use an outlet check the crankcase would pull air in through the inlet check and the pressure line, reducing overall tank pressure and perhaps retaining more lube in the crankcase.


In order to set up this system to provide roughly 1 psi at wot I'll start and run the engine off of muffler pressure first while monitoring the checked crankcase output pressure. It should just be a matter of selecting the correct size orifice to bleed off excess pressure. The solenoid will be used for fueling as normal on this go around. If this works as good as muffler pressure the crap trap is history for $10, the cost of an inline check valve and a plastic tee fitting. I may need to add a remote needle to control bleed off pressure, or maybe a piece of brass tubing that can be crimped, not sure yet.

Here's my thinking; When using a fixed air bleed orifice (Tee'd into the pressure line), the more air volume pumped the higher the tank pressure will be. I'm not sure if the pressure rise with rpm will be linear or exponential, but I'm guessing exponential based on my muffler pressure tests.

Originally Posted by 1967brutus

Meanwhile: How to do more of the same and still keep it somewhat "interesting":

Still a first and rough attempt, the OS/Graupner Wankel (Mk I) running on gas, with the electronic mixture control.

The changes are extremely remarkable:
-Barely any crud from the muffler anymore
-It appears to be quieter, which I think has to do with no more afterburning in the muffler.
-Fuel economy has improved by at least a factor 3 if not 4. I was really amazed that the same fuel tank that normally would be empty within 5~7 minutes even at mainly part load, now allready feeds the engine for 20 minutes at the same throttle regime, and at least 1.3rd still left.
-Idle and partload, no more fuel spray from the carb, and idle now happens at throttle openings as used from a normal reciprocating engine, instead of "half open and slobbering rich".
-Noticably lower running temperatures, at least at idle and part throttle, although I have not yet had the balls to keep it flat-out for prolonged periods of time, because lower than "searing hot" still is pretty hot. Yet, the cooling ring remained cooler, and it had all apearance that after reducing throttle, temperatures dropped quicker as well.
I tried to measure the "core temp" and the highest reading I could get was 148 deg C by IR-gun, at which temperature the engine did not show ANY signs of overheating, but yet... Brrrr,
But what is VERY noticable is the lower exhaust temperature at partload. I held my hand at 3"behind the tailpipe to see how much oil the engine is spewing, and that was no problem up to about 8K RPM.

It has all appearance that a wankel, just like so far all the engines I have done, needs time to "settle" on the changed lubricating conditions, because throughout the test the engine started to run better and wanted an ever so slightly leaner mixture.
The oil in the engine is less diluted by fuel therefore more viscous and less voluminous, and less polluted by soot. It appears this reduces internal friction.

It is an entirely different engine now... Still a bit tricky to get going, still very sensitive to the mixture, but all in all it still is improving as well.

I saw a peak of a touch over 13K (13050) with an APC 9 x 5, which should translate to 0,47 hp, and that is a fraction more than I have seen from this engine so far.
Previous peak was 12960. That was in December last year, so lower temperatures and higher air density.

I'm happy...