Thread: Interesting split cycle engine

Originally Posted by austastar

Hi,
found this link that others may be interested in.
cheers

built in supercharger + the storage bit (which makes the difference in economy I would say)

Smells like BS to me.
I can see a lot of downsides (like enormous pumping losses) and nothing to give the proclaimed combustion efficiency benefits.

If they publish BSFC charts for their test engines I'd like to see them.

Originally Posted by Dougal

Smells like BS to me.
I can see a lot of downsides (like enormous pumping losses) and nothing to give the proclaimed combustion efficiency benefits.

If they publish BSFC charts for their test engines I'd like to see them.

Nothing like keeping an open mind, is there!!

The firing after TDC seems to be the breakthrough here, as it does significantly reduce pumping losses.

It remains to be seen whether it works well or not, but increasing restriction on NOx emissions is going to be a big challenge for engine makers (particularly diesel) in the future, and if this design can reduce that it's a plus.

I like the air-hybrid potential, but I remain to be convinced on that one.

Cheers,

Lionel

Originally Posted by Lionel

The firing after TDC seems to be the breakthrough here, as it does significantly reduce pumping losses.

Yet all the downsides to firing after TDC on conventional engines still apply, the main one being a big drop in efficiency and fuel economy which drowns the reduction in pumping losses.

Set the timing on any petrol or diesel to after tdc and see how it runs. They probably run okay at 1000-1500rpm.

I don't think comparing a conventional internal combustion engine firing after TDC with this one firing after TDC is necessarily a valid comparison.

If their explanation is accurate, "the high pressure air entering the cylinder and resulting massive turbulence" overcomes or at least reduces the usual disadvantages of after TDC timing.

They claim their 1 litre engine produces 135hp at 6000 revs.

They might be onto something. Time will tell. I do think I have heard these sorts of claims before, but maybe one day someone will get it right.

So they have a 1 litre engine producing 135hp at 6000rpm.
That's 100kw and works out to ~160Nm.

Sounds impressive for a 1 litre engine. But this 1 litre engine is effectively 2 stroke and pumps the same air and fuel as a 2 litre 4 stroke engine.
135hp from a 2 litre 4 stroke at 6000rpm is rather average. Especially as there's no mention of emissions controls which existing engines meet and still produce far better figures.

I remain skeptical, the whole feel of the web presentation is one tailored to trolling for investors. If you think it's a solid investment, feel free to part with your money. The name "split cycle" has previously been used to scam investors. I don't beleive this is a similar scam, but I also don't beleive it's going to challenge 4 stroke engines anytime soon.
[ame="http://en.wikipedia.org/wiki/Split_cycle_engine"]Split cycle engine - Wikipedia, the free encyclopedia[/ame]

I'm glad you have my financial interests at heart, but don't worry; I have no intention of investing in this venture.

I will need a lot more evidence before I am convinced that this design is a goer.

I was just responding to a couple of specific points in your earlier post. You had used the way a conventional engine runs with ATDC timing as a reason to suggest that this design might be OK at idling speeds. I just thought that fact that it produced even average power at 6000 rpm suggested that that it could run reasonably efficiently at much higher revs.

I am not getting excited about the possibility of this engine revolutionising the automotive world. I was just making the point that they CLAIM to have solved the usual problems associated with ATDC timing.

It may be a lot of fuss about nothing and may turn out to be quite impractial, but as the OP said, it is interesting.

I find this one interesting too.

[ame="http://www.youtube.com/watch?v=uP7gGUCPJj0&NR=1"]YouTube - OPOC.avi[/ame]