I’ll be honest with you. I’m very surprised by the interest and enthusiasm that this engine generated. But the interest and enthusiasm is obviously there and it doesn’t seem to be going away and that tells me that it’s time for someone to pour a big ol’ bucket of depressing reality to extinguish all that wonderful youthful enthusiasm. And I decided that someone will be me. So let’s get started.

I’ll say it right off the bat. This is a very creative and out of the box design. However being creative, does not necessarily mean that it is capable of penetrating the vehicular market or revolutionizing anything. The first patent related to this engine is from 1974 and the inventor Eduardo Taurozzi worked on the engine and promoted it throughout the 70’s, 80s and 90s and since then it has never been mass produced in a vehicular application, not even a small or limited production. 1974 was 50 years ago. That is half a century. If development started 10 or even 20 years ago there would still be hope, because getting new designs to the market usually takes a lot of time and research and development and fighting to prove their merit and so on and so forth. But 1974 is telling us with great certainty that we will not be seeing this in a mass produced car or motorcycle, probably ever.

But it’s very important to understand the following. The friction between the piston, essentially the piston skirt and the cylinder is very very small in a conventional engine. Remember we’re not speaking about the piston rings here. This engine still has piston rings to contain the air fuel mixture and the combustion in the combustion chamber and these rings are still a source of friction, a much greater amount of friction than the friction between the piston skirt and the cylinder walls. There is no contact between the piston skirt and the cylinder walls. Contact between the two is prevented because a layer of oil is constantly splashed and/or sprayed onto the cylinder wall and the piston skirt then rides on this film of oil.

the piston skirt does still subject the cylinder wall to significant loads. When combustion occurs the major thrust side of the piston places a significant load on the cylinder wall. Load is placed here because of the position of the rod and the crankshaft in relation to the piston. The load of combustion acts normally on the piston and it’s pushing it down. But the rod is angled, the wrist pin is right under the center of this load whereas the rest of the rod is offset from the center of the load. The result is that the rod is trying to flip over. As it’s trying to flip over it pushes the major thrust side of the piston into the wall, However oil is great at resisting loads and if the engine is working as it should this load can never disperse or break apart the film of oil and the piston skirt and the cylinder wall never make contact.

However, this load still creates friction and it’s the reason why cylinders wear oval over the life of the engine. But remember, the life of the average engine in a car is around 300.000 kilometers. Uneven cylinder wear is a problem that has been solved long ago. It does not shorten the life of the engine.

So let’s address the claim, 30% reduced fuel consumption. The friction that stems from the entire piston assembly accounts for around 45% of the entire frictional losses of the engine. Frictional losses account for only 10-15% of the overall losses of the engine. If we completely eliminate the piston related friction than we have eliminated only 45% of this 15%. That means that we have reduced overall efficiency only by 6.75%. But of course it’s not 6.75 because we have been massively over-optimistic here. Our hinge does not eliminate the piston rings and it does not eliminate the wrist pin. So it does not eliminate the 45% friction. Of this 45% piston skirt friction accounts for 12.5% percent, rings are around 22.5% percent and the wrist pin is the remaining 10%. We eliminate the piston skirt friction, let’s assume that we reduce ring friction by half since we get rid of the oil control ring pack and we eliminate piston rocking. We don’t really do anything about the wrist pin. So the hinge more realistically eliminates something like 21.25% of the total friction, not 45%. And this gives us a total potential efficiency increase and fuel consumption reduction of 3.2%.

A special thank you to my patrons:
Daniel
Pepe
Brian Alvarez
Peter Della Flora
Dave Westwood
Joe C
Zwoa Meda Beda
Toma Marini
Cole Philips

00:00 2 solutions, 3 problems
02:41 Skirt friction
08:29 30% more efficient?
11:09 Sealed bearings
16:16 Balance and manufacturing
20:57 Ring torture