Waissi Engine Update: The Differences Between Waissi and Bourke Engines

Ronnie Schreiber
by Ronnie Schreiber
waissi engine update the differences between waissi and bourke engines

Bourke Engine (click for animation)

In a comment to my post last month about Professor Gary Waissi’s new piston engine that has no connecting rods between the pistons and the crankshaft, Bourke Engine, invented by Russell Bourke. Based on the diagrams of the Bourke motor, that seemed like a good question, so I asked Prof. Waissi about it. I received his reply today. Waissi said that while there were similarities between his engine and Bourke’s, there were also substantial differences, resulting in the Bourke engine having more operating friction. Dr. Waissi also said that he hoped to have a two-cylinder prototype of his own design assembled and running by the end of this year. Waissi’s response after the jump.

Thank you for the message, and for writing the article. I am very familiar with the Bourke engine and concept; a Scotch Yoke engine. A number of similarities, including aligned cylinders, and connected piston structure. The main difference is, as clearly shown in the animation, that the Bourke Engine uses a “conventional” crankshaft with “yoke”. There is no “yoke” in the Waissi Engine, because the crankshaft is like a camshaft (a straight shaft).

The Bourke engine does also not use hydrodynamic lubrication in-between the bearing rings, which does not, in my estimation, reduce the friction, but increases it. Both engines, the Bourke and the Waissi Engine, have only primary piston forces (because of no piston rods), and therefore are simpler to balance. In the Waissi Engine design the crankshaft is actually like a camshaft — a straight shaft; and an off-set camdisk, and a hydrodynamically lubricated bearing ring. The bearing ring has a significantly larger surface area (between the inside surface of the ring and the disk outer perimeter) distributing the piston force to a larger area resulting into a lower bearing pressure.

Another advantage of the Waissi Engine is manufacturability — straight shaft vs. crankshaft — especially with multi-cylinder engines; you can use the same cam(crank)shaft for engines with different piston strokes, by just changing the disk (as the stroke depends on the disk off-set). For example in an F-1 engine the stroke is 40 mm; andf for “regular” engines the stroke varies widely (60- 70- 80- 90- 100 mm). With regular engine designs, including the Bourke engine, for every variation you need a new crankshaft. With the Waissi Engine from a F-1 engine to a pick-up truck engine you need just one.

I am currently working on a two-cylinder version of the Waissi Engine. My plan includes to get a testable version running before the end of the year. (A two-cylinder version, because it is cheaper to build).

Ronnie Schreiber edits Cars In Depth, a realistic perspective on cars & car culture and the original 3D car site. If you found this post worthwhile, you can dig deeper at Cars In Depth. If the 3D thing freaks you out, don’t worry, all the photo and video players in use at the site have mono options. Thanks for reading – RJS

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6 of 33 comments
  • Claytori Claytori on Aug 13, 2013

    The only differences I see between the Wasai and the Bourke are the diameter of the crankpin journal and the structural method of connecting the two opposed pistons. Whether you you use anti-friction (Bourke) or fluid film (Wasai) is moot. If i were to bet on which is lower friction, I would put my money on Bourke. A problem that both these engines have is balance. Unlike an opposed twin crank engine, the pistons do not "box". Instead they shuffle back and forth. Yes, you can put a balance weight on the crank/eccentric to oppose the reciprocating mass, but then you introduce an unopposed reciprocating mass acting perpendicular to the piston. Some designs of these types of engines use two pairs of pistons in a cross type arrangement to deal with this. But then you will still have the second order (moment) shaking forces to deal with. I agree with the commenters who pointed out that this mechanical fiddling doesn't do anything to improve the thermal efficiency. What is needed is something that turns more of the fuel energy into mechanical work instead of lost heat. The other area is part throttle efficiency, which is dismal for spark ignition engines.

    • See 3 previous
    • Porschespeed Porschespeed on Aug 16, 2013

      @Luke42 Very true, it's easy to see the future - it's just hard to attach an accurate date to it... Here's my case for why I see them coming in rather less than a decade on serial production vehicles. Check out my points and then make your own call. 1. It works. F1 cars have had various pneumatic and/or electro-hydraulic hybrid valve operators since the mid-1980s. Sure it needed development and it got it. Straight electric is still not quite there, but there's things afoot. Easy diagram... http://scarbsf1.com/valves.html 2. There's a ton of folks actively working on this with cubic feet of cash. Here's just one... http://www.launchpnt.com/portfolio/transportation/electromechanical-valve-actuator/ 3. Save for coatings, alloys, and treatments, fully controllable valve actuation is one of the final frontiers for the ICE. As regs tighten, it just has to happen - there are no options. 4. Honestly, people with way more resources than me have been at this since the mid 70s. My friends and I modded a Briggs lawnmower engine to run with no cam on hand-wound solenoids and the stone-age analog electronics we could afford in the early 80s - even though we knew we weren't going to be the ones who did it, we knew that it would happen eventually. (talk about cobbled together opto-electronic triggers and breadboards!) It's really that the tech, computing power, and cheap manufacturing have caught up with the ideas that many had 40 years ago. Much like active suspension (which has been in process for 2 decades at Bose) it's just waiting for the prices to drop and the market to not only demand it, but require it.

  • Fredric21 Fredric21 on May 13, 2016

    After three years, the inventor couldn't afford to renew the patent, which resigns this idea to oblivion, like many others. I'm afraid it takes $millions to even build a prototype and patent it. I should know, because I'm in the process of doing that very thing myself. I can never understand why people make their ideas public before they are able to substantiate their claims with real numbers taken off the dynamometer.

  • ToolGuy CXXVIII comments?!?
  • ToolGuy I did truck things with my truck this past week, twenty-odd miles from home (farther than usual). Recall that the interior bed space of my (modified) truck is 98" x 74". On the ride home yesterday the bed carried a 20 foot extension ladder (10 feet long, flagged 14 inches past the rear bumper), two other ladders, a smallish air compressor, a largish shop vac, three large bins, some materials, some scrap, and a slew of tool cases/bags. It was pretty full, is what I'm saying.The range of the Cybertruck would have been just fine. Nothing I carried had any substantial weight to it, in truck terms. The frunk would have been extremely useful (lock the tool cases there, out of the way of the Bed Stuff, away from prying eyes and grasping fingers -- you say I can charge my cordless tools there? bonus). Stainless steel plus no paint is a plus.Apparently the Cybertruck bed will be 78" long (but over 96" with the tailgate folded down) and 60-65" wide. And then Tesla promises "100 cubic feet of exterior, lockable storage — including the under-bed, frunk and sail pillars." Underbed storage requires the bed to be clear of other stuff, but bottom line everything would have fit, especially when we consider the second row of seats (tools and some materials out of the weather).Some days I was hauling mostly air on one leg of the trip. There were several store runs involved, some for 8-foot stock. One day I bummed a ride in a Roush Mustang. Three separate times other drivers tried to run into my truck (stainless steel panels, yes please). The fuel savings would be large enough for me to notice and to care.TL;DR: This truck would work for me, as a truck. Sample size = 1.
  • Art Vandelay Dodge should bring this back. They could sell it as the classic classic classic model
  • Surferjoe Still have a 2013 RDX, naturally aspirated V6, just can't get behind a 4 banger turbo.Also gloriously absent, ESS, lane departure warnings, etc.
  • ToolGuy Is it a genuine Top Hand? Oh, I forgot, I don't care. 🙂