Creating a perfectly balanced gasoline 4 CYL engine - with no balance shafts?

[FelixDeCat]

This is an enlightening video explaining the efficiencies of the 4 cylinder engine and its biggest limitations - using balance shafts which are extra weights added to counter imbalanced dynamic forces (adding weight and friction) and the fact that mass produced gasoline fours are limited to around 3.0 liter displacement. The first half of the the video explains these in detail from the ground up. Watch a 1.25x to get the information quickly.


The second half of the video (which is time indexed) describes a project that supposedly has a "reinvented" connecting rod, which is the source of engine imbalance and is also able to displace 7.5L @ 5000RPM for 654HP. The initial engine is meant to be an outboard motor for boats.


The video maker is skeptical since this would be an incredible and valuable discovery and could be "too good to be true."

 

[Heartbreaker]

I already watched that video before and there is no detail at all on how they did this.

They claim their design is patented, so they should be showing it off to the world, now that they have patent protection.

Edit: Found the patent:

US10378578B1 - Internal combustion engine using yoke assemblies in unopposed cylinder units - Google Patents

An internal combustion engine includes one or more unopposed cylinder units where each cylinder unit drives the crankshaft via a yoke assembly rather than a conventional connecting rod. The yoke assembly is formed by a connecting rod assembly that can have an upper portion having a connecting...

patents.google.com

 

[herm0016]

because 16 extra sliding surfaces should reduce friction over 3 easily lubricated rotating bearings with no thrust on them?

seems like its just an over complicated way to do it.

I want to see someone build a commercial opposing cylinder engine.

 

[Heartbreaker]

because 16 extra sliding surfaces should reduce friction over 3 easily lubricated rotating bearings with no thrust on them?

seems like its just an over complicated way to do it.

I want to see someone build a commercial opposing cylinder engine.

It will increase friction, but the point is to get rid of i4 engine imbalance.

 

[herm0016]

It will increase friction, but the point is to get rid of i4 engine imbalance.

the goal is efficiency. seems like a boxer or a 90* v4 is a better way having primary and secondary balance natively.

 

[Heartbreaker]

the goal is efficiency. seems like a boxer or a 90* v4 is a better way having primary and secondary balance natively.

For this application (outboard motors), packaging efficiency is large factor. Making I4 configuration ideal. Have you ever seen a boxer or v4 outboard motor?

 

[herm0016]

eh? tons of V4 outboards. 60's and 90's i cant off the top of my head think of any 4 strokes, but plenty of 2s from Evinrude and Yamaha. plenty of v6/v8 and even a v12 that is new now.

i wonder what the 4 stroke issue is, could be packaging and/or cost. I see the problem this "solves" but I don't see this having a great advantage. many things can be redesigned, but actually improving them is much harder than coming up with a way that is different.

 

[Heartbreaker]

I see the problem this "solves" but I don't see this having a great advantage. many things can be redesigned, but actually improving them is much harder than coming up with a way that is different.

Inline engine 4 will be simpler to design and manufacture than a V4 or boxer. One cylinder bank vs two.

Inline 4 already dominate the automotive market over Boxer and V4 despite poor balance.

For automotive use right now if you need more power than a NA 2.5L i4, it either Turbo Charging or V6.

But if you could build a perfectly smooth i4 in the 3.0L to 3.5L capacity that would be a great option.

 

[Meghan54]

Too bad the engine design that's inherently balanced, an I-6, is just too damned long for fwd use.

 

[FelixDeCat]

Too bad the engine design that's inherently balanced, an I-6, is just too damned long for fwd use.

The answer? A even firing 90 degree or 60 degree V shaped dual bank 6 cylinder.........or is it?

I used to own a 1977 and a 1978 280z back in late 80s / early 90s. There were lots of fun both had a long engine bay to accommodate the fun to drive and extremely easy to work on In Line 6 Cylinder Engine.

 

[Heartbreaker]

Update interview with CEO.

Still ZERO about the tech that makes it work. Patents pending, and they don't want to say anything about design until patent granted.

IMO, no one should invest in something like this before you see the patents, since that is the whole point.

 

[RLGL]

i wonder what the 4 stroke issue is, could be packaging and/or cost. I

The 4 stroke outboards are so smooth that one can set a beer on the cowling while running and not kill the head of foam.

 

[fralexandr]

Rotary. Not exactly a 4 cylinder, and it has other issues like burning oil, but it's well balanced without a balance shaft.

 

[FelixDeCat]

Update interview with CEO.

Still ZERO about the tech that makes it work. Patents pending, and they don't want to say anything about design until patent granted.

IMO, no one should invest in something like this before you see the patents, since that is the whole point.

Another good video, but he could not give more details due to patents pending in foreign countries. If you know anything about patents, "prior artwork" is a big issue, so it makes sense you want to keep certain details under wraps for now.

He did make an interesting point however around the 13 minute mark. As of now, it is far more feasible and economical to run a gasoline powered engine on a boat due to way gasoline can be stored in a much smaller container and deliver run time at full throttle for hours vs the size and weight of a battery necessary to deliver the same amount of performance.

There simply is no comparison and that include theoretical improvements in battery density to energy storage ratios in the future:

 

[FelixDeCat]

Rotary. Not exactly a 4 cylinder, and it has other issues like burning oil, but it's well balanced without a balance shaft.

Interesting. Almost seems to need its own thread covering experimental rotary engines.