"12 stroke", 2 stroke on demand, HCCI, etc. - the Digital Engine

[Laconian]

https://newatlas.com/camcon-digital-iva-valve-system/55827/

High bandwidth valvetrain control, lots of intriguing possibilities...

[CaminoRacer]

Guess they haven't heard of FreeValve.

[12,000 RPM]

Lots of ways to slice it. I'm still bullish on electrification. Expensive, but relatively simple and reliable. Will be cool if they actually implement this though.

I'm also very intrigued by the opposed piston 2 strokes....

[Galaxy]

Guess they haven't heard of FreeValve.

They updated the article at the end because of FreeValve.

[CaminoRacer]

They updated the article at the end because of FreeValve.

Ah, I see.

I suppose this new system does allow more freedom, since you can install a very high lift, high duration cam and then only go part of the way up for low-rpm cruising, then return back down the lobe instead of cresting it.

[Laconian]

I thought MultiAir engines could deliver some of these great things, but aren't those engines all turds?

[giant_mtb]

Powervalves on everything.

[Galaxy]

I thought MultiAir engines could deliver some of these great things, but aren't those engines all turds?

I wondered about that as well. I guess deficiencies in other areas of the engine counteract the advanced engine control potential of multiair. Plus Multiair is a hydraulic system, that adds a lot of problems.

[MX793]

I thought MultiAir engines could deliver some of these great things, but aren't those engines all turds?

Fancy heads on 25-30 year old engine designs (FIRES engine that Fiat uses came out in 1985).  Plus, the Italians don't have a great reputation for robust, complicated designs.

[12,000 RPM]

I love N/A engines but as far as efficiency goes I'm feeling like the biggest ROIs are in recapturing waste energy.... be it from the exhaust or the brakes. Character is always going to come at the expense of efficiency.... if these heads allow high revving, the rest of the engine will have to be designed around that and be less efficient overall. And I think people who prioritize engine character *generally* don't care about fuel economy.

So for my money I'd rather have the investments and focus be made in recapturing waste heat. Out of the losses pie that's where the bulk of the pain is. Plus there are huge gains to be made just in overall engine design. Look at Toyota's new 2.0L:

https://newsroom.toyota.co.jp/en/powertrain2018/engine/

It's a regular old NA engine. But through a holistic focus on efficiency and simplicity they've achieved record high thermal efficiencies in engines going into ~$20K cars. Imagine that focus integrated with an electric turbo and regenerative braking. All of a sudden fancy valvetrains become a bit expensive. Which is why I think automakers have pulled away from them.

[r0tor]

I thought MultiAir engines could deliver some of these great things, but aren't those engines all turds?

The multiair 2 in the alfa giulia/stelvio is pretty stout... Capable of ~350hp and 35 mpg with a tune

[MrH]

I thought MultiAir engines could deliver some of these great things, but aren't those engines all turds?

Yes.  Yes they are.

[GoCougs]

Guess they haven't heard of FreeValve.

FreeValve uses air and the like; this is purely electromechanical.

[FoMoJo]

Guess they haven't heard of FreeValve.

Does Koenigsegg's system have the ability to limit the opening of the valves?  Haven't kept up with it lately.

[12,000 RPM]

Koenigsegg has full control of the valves