Koenigsegg free valve system

[Isaac Zachary]

Wouldn't the overhead valve problem only apply if it has valve/piston interference? If there's no interference then the engine should technically still be able to run on the other cylinders. My dad once had a V8 with a valve stuck open and he kept driving on seven cylinders.

Unless the intake allows the spark to reach the manifold with a stuck intake valve. I remember my dad disconnected that one cylinder's sparkplug wire because he was afraid it would backfire up through the carb. Or maybe it was backfiring and wouldn't start as a result. I can't quite remember.

What I do remember is that it ran pretty well on seven cylinders, at least after he disconnected the sparkplug wire to that one cylinder with the stuck valve.

[Piotrsko]

Originally Posted by freebeard

Interesting. SAFE
When a valve of an overhead valve engine fails, the engine stops and an emergency landing usually ensues. When a valve of a side valve engine fails, only one cylinder ceases to function and the plane has the power to make a landing at the nearest airport, saving both airframe and passengers!

Partially correct. If the valve failure doesn't affect the combustion chamber (typical because it's usually the exhaust valve that fails open) and If you have an appropriate altitude you could make the airport engine off, but 75% power should be what you're cruising at. If you're mantaining 75% power, and no other issues you continue the flight if you haven't soiled your pants. Except for the soiled issue BTDT. You can maintain level flight all the way down to 50% power, but you're flying really slow.

Iirc, the reason we don't have slide valves on aircraft is they tend to get stuck often or they stop sealing due to the extreme rich mixtures fouling the guides.

Drove a dodge van like that for a long while as a 7 cylinder with the plug wire removed on a non computer distributor. Doubt the new stuff would allow that, might run until you turn it off but wouldn't restart.. Dont have anything that uses sparkplugs anymore to try it.

[freebeard]

Partially correct.

That's why I labelled it 'interesting'.

[cRiPpLe_rOoStEr]

Originally Posted by Isaac Zachary

Wouldn't the overhead valve problem only apply if it has valve/piston interference? If there's no interference then the engine should technically still be able to run on the other cylinders. My dad once had a V8 with a valve stuck open and he kept driving on seven cylinders.

AFAIK nowadays most engines have interference.

[Isaac Zachary]

Originally Posted by cRiPpLe_rOoStEr

AFAIK nowadays most engines have interference.

True. But it seems kind of silly to make it a flathead engine just to make sure it won't be an interference engine.

That would be like making it have points just to make sure it's not a wasted spark system.

[R.W.Dale]

When an intake valve sticks you still have a massive internal vacuum leak and huge loss of power. Side valve or not. An engine does not happily run on the other cylinders

Freevalve is default closed. With no camshaft in the mix a valve will be closed unless valve retention is lost. Interference isn't even a concept that applies unless you can somehow fall electronically out of sync

[cRiPpLe_rOoStEr]

Originally Posted by Isaac Zachary

it seems kind of silly to make it a flathead engine just to make sure it won't be an interference engine

If I would ever make a flathead engine, or fit an off-the-shelf one into a vehicle, I would do it because they look cool to me, even though some OHV could serve me eventually better.

That would be like making it have points just to make sure it's not a wasted spark system.

Odd enough, IIRC some old motorcycle ignition systems which had points were actually wasted-spark too.

[oil pan 4]

Figured it was DOA.
https://youtu.be/XV4NavUIznc

https://m.youtube.com/watch?v=XV4Nav...ature=youtu.be

[freebeard]

Watched that video, wasn't impressed -- comparing 1.6L engines in various states of tune with 211/230/300 didn't prove much. VVT made the least difference.

I'd consider the boxer four from the 1930s with 25-60HP. A newly designed engine case[s halves] with the freevalve technology built into it and oil-cooled flat heads producing 230-300HP would be acceptable. Especially if it would weigh less. No throttle body and improved emissions just the gravy with a cherry on top.

edit: Almost forgot



Maybe a VR-12 flat motor?

Originally Posted by Wikipedia

Design
See also: Flat engine
Unlike most flat-twin, flat-four, and flat-six engines, flat-twelve engines typically use the crankshaft configuration of a 180° V engine. Instead of the boxer engine design of each piston having its own crankpin, flat-twelve engines have each pair of pistons sharing a crankpin, and thus are flat, but not boxers.

[cRiPpLe_rOoStEr]

Originally Posted by oil pan 4

Figured it was DOA.

I didn't really expect it to become mainstream so soon, but there might be some applications to which Freevalve is eventually reasonable to say the least.

Now that newer direct-injection gassers (and flexfuels too) are plagued by the particulate filters, just like Diesels have been for a while, a claim that Freevalve would keep port-injection competitive still sounds interesting, as port-injection fares better when it comes to PM and NOx, so it would allow for a much simpler aftertreatment.