Hi Jonnychooch,
Thanks for you interest!
what temperatures did you see in the charged air from your design.
I never was able to keep it running long enough to measure it. Theoretically it will pick up internal heat from the hot engine parts as well as heat from being compressed.
On a factory designed inline 4,5,6 cylinder, v8 ,v10 , v12 etc engine you would need some major redesign work due to the negative effect of apposing piston stroke on a open block design which would cancel out the positive pressure cycle,the need to chamber each individual cylinder into compartments throughout would be required.
Correct. No open block design for this to work. In line engines would require main bearings and their supporting web between each adjacent cylinder. This is desirable anyway for a high performance engine. Opposed engines would require a main bearing and web between adjacent opposed pairs. And v type engines could use a different crankshaft with overlaping rod journals, so that both pistons (across from each other) traveled up and down at the same time. This is already done in 90deg v6 engines.
None of this would be difficult to do in an engine designed from the ground up. However, modifying most existing engines would be more problematic.
Issues with increase back pressure would force atmosphere into oil system via all open internal oil journals and thus reduce oil flow due to pressure difference, probably best to require supply and return oil ways with seals.
The problem isn't oil pressure and oil flow to the bearings. That can be increased a small amount to compensate for the slight pressure (2 psi to max 15 psi) in the crankcase. The problem is all the oil that escapes into the airstream and has to later be separated from the induction air! A sealed lubrication system could be used to totally eliminate oil entering the air stream along the lines you sugested.
problems with piston ring oiling / sealing due to crank side pressure , probably different tolerances required and sealing redesign for correction.
I have several ideas for solving these issues with a sealed lube system. And these issues are not a problem with a conventional lube system that requires air/oil separation.
The oil starvation issues can be partly over come with a proper dry sump setup , remote oil reservoir, multi stage oil pump and collection system.
This is what I started to do when I tore down the engine and found bearing damage. I was only able to run the engine for a few minutes before all the oil would get trapped in the separator and I would have to shut it down.
Was never able to drive it this way, so I blocked off the intake reeds and unhooked the boost plumbing from the carb and drove the car that way for a couple of years or so. Because the oil sump I made was not properly baffled, it would starve the engine for oil during hard cornering. And some of the epoxy I used to "stuff" the crankcase and seal the intake reed valves came loose and wound up in the oil supply! Not good! This is what caused the bearing damage, along with high oil temps caused by elimination of the factory oil cooler. .......IF induction air had been flowing through the crankcase all the time, it would have cooled the oil and heated the air as per my design.
Piston to cylinder wall lubrication would need some fancy work.
Only with a sealed lube system. Not a problem with the conventional lube system and air/oil separation.
Gudgeon pin lubrication would need separate supply and return oil ways & oil seals to reduce oil vapor and positive pressure reversal causing reduced lubrication.
Again, not a problem except with the completely sealed lube system. I have incorporated all the required lube points in a totally sealed system idea I have. Never built it!
The concept is totally possible as you have proved but without complete block , crankshafts, conrods etc being redesign to deal with much of above , and as you stated you found the engine very close to failure due to oil lubrication problems, ouch.
The main failure was the
inability to separate out the oil, and then running it in normally aspirated mode for two years while the epoxy was letting loose inside the engine! And yes, I have contemplated building a complete engine from the ground up. Decided the cost and time required are beyond my present means.