Primary and Secondary Imbalance - Alfadan Outboard Motor ?

[tpenfield]

@Scott Danforth . . . & others www.startengine.com

I just came across this conceptual engine that supposedly addresses the issue of primary and secondary imbalance of internal combustion engines, which limits the size of the cylinders.

I am wonder if anyone has come across this and what your take may be - Innovation or smoke & mirrors?

 

[Scott Danforth]

not sure what you linked to.

however there are many concept engines. most of which can not be built on mass scale.

the coats rotary valve motor comes to mind.

Koenigsegg's little 2 liter is another.

 

[tpenfield]

not sure what you linked to.

however there are many concept engines. most of which can not be built on mass scale.

the coats rotary valve motor comes to mind.

Koenigsegg's little 2 liter is another.

Oopps, my bad . . .
Here is a better link . . .
https://www.alfadan.com/

 

[Scott Danforth]

another investment link

 

[alldodge]

Has some ice pics but 50% more hp and 50% less fuel . Also listed as previous crowd sourced for over $1M. Now there wanting more

Lots of long vids, no time to spend that much time right now
https://www.alfadan.com/videos

 

[tpenfield]

It seems like they have (somehow) addressed the secondary imbalance issue and can then go with larger cylinders. It seems to imply that there is a practical limit to cylinder & piston size (i.e. weight) . . . so more power tends to require more cylinders in conventional designs.

I know that Merc uses 12 cylinders to get 600 HP, whereas these guys 'say' they can do it (600 +/- HP) with 4 cylinders .

Mostly just theory at this point, not sure if they even have a working prototype. Might be cool if it all plays out though . . .

 

[Bob_VT]

Pure physical dimensions comes to mind. a single 1875 cc piston would be say 8" or so! Basically what has been described is a inline 4 that has been supersized. They are making up by increasing the volume to reduce the connecting rod. I hope they can do it. It is interesting

 

[Scott Danforth]

the merc 12 cylinder is a variation of an LS motor (a departure from their small displacement supercharged outboard architecture). so getting 600 hp out of their V12 was an easy feat, especially at 7.6 liters.

the Alfadan is 8.4 liters and 4 cylinders. that is 2.1 liters per cylinder. about 146mm bore and 125mm stroke based on one website.

Volvo dropped the ball when they killed off Seven Marine. the trail was blazed

 

[tpenfield]

Interesting stuff . . . I am just wondering what they (Alfadan) has figured out about the imbalance, where others have not . I assume that is what allows them to go up in cylinder size.

As far as engine performance, I often like to look at HP/Litre as a guide.

The traditional style engines seemed to be getting upwards of 52 HP/Litre (7.4, 8.1, 8.2 GM Big Blocks)

V-P 380 . . . 61.3 HP/L

The new Merc V-12 . . . 78.9 HP/L

Alfadan would be around the same 77.85 HP/L (with 1/3 the number of cylinders)

The old style Verados . . . 115 HP/L !!!
Let's hear it for supercharging

New Style Verados . . . 65 HP/L

 

[tpenfield]

I also wonder if having opposing cylinders on the same crankshaft/bearing point (aka 'flat' twins/quads) would address the imbalance ? Not as compact a design though . . .

 

[Scott Danforth]

I also wonder if having opposing cylinders on the same crankshaft/bearing point (aka 'flat' twins/quads) would address the imbalance ? Not as compact a design though . . .

yes, hence the boxer motors that Subaru and BMW motorcycles are fond of .