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Home > Forums > Automotive Engineers > Activities > Engine & fuel engineering Forum

Scuderi~Split Cycle Engine, anything to it?(2)

Read More Threads Like This One

ornerynorsk (Industrial)

12 Apr 12 15:24

http://www.foxnews.com/leisure/2012/04/10/scuderi-files-patent-for-split-cycle-engine/

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

jmw (Industrial)

12 Apr 12 16:49

Oh Snap..... I posted on this in the Engine and Turbine engineering forum.
My question was whether the balance was right between increased complexity and advantage.

JMW
www.ViscoAnalyser.com

ornerynorsk (Industrial)

12 Apr 12 16:52

Sorry JMW, didn't see your posting. Please re-route to JMW's link, all.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

jmw (Industrial)

12 Apr 12 18:26

Na.
Here is OK and it isn't a double post because different people posted.
Not everyone covers both forums so its justification enough to leave both running.

JMW
www.ViscoAnalyser.com

GregLocock (Automotive)

12 Apr 12 18:49

1) The Twingle engine of the 1920s

2) Anybody equipped with a copy of Heywood and a brain can identify the likely reasons why its performance (in a general sense) is likely to be ho hum. There are some offsetting advantages, maybe there is some magic there. They have sternly resisted the temptation to publish hard numbers for efficiency and bsfc and power.

3) They have a lot of lawyers and money

Nuff said.

Cheers

Greg Locock

New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

GregLocock (Automotive)

15 Apr 12 5:02

Couple of idle thoughts

1) why is the charging cylinder the same displacement as the combustion cylinder?

2) has anybody got a quick estimate of the losses associated with the redundant compression/transfer/expansion portion of this engine's cycle?

Incidentally underneath the hood there are a lot of similarities with our old friend the Bourke engine, and really with any crankcase charged two stroke.

Cheers

Greg Locock

New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

MikeHalloran (Mechanical)

15 Apr 12 13:50

1) I think it was just easier to 'split a four' for the ancient prototype that way. Some recent illustrations suggest a difference in bore, but I haven't noticed any specific discussion of the point.

I suspect the primary reason for not exploring simple alternatives is that every configuration change becomes an excuse for the Research Institute that's been eating their money to restart the simulation build effort from scratch.

I haven't been able to get a straight answer about how many actual engines exist, or ever existed. The published claims seem to be all based on simulations.

Mike Halloran
Pembroke Pines, FL, USA

jmw (Industrial)

15 Apr 12 18:13

Try this website which includes a diagram showing different chamber sizes.

JMW
www.ViscoAnalyser.com

jmw (Industrial)

15 Apr 12 18:14

Mike, it seems the fox news link has a better diagram.

JMW
www.ViscoAnalyser.com

SMOKEY44211 (Automotive)

23 Apr 12 10:06

I was able to get BSFC #s from one of thier engineers at the SAE conference in Washington D.C. last year. 296g/Kwh. Nothing spectacular. Have to give them credit for thier ability to raise money, too bad they're flushing it down the toilet on this dog.----Phil

jmw (Industrial)

24 Apr 12 6:53

BSFC #s ?
Sorry, I'm not from the texting generation.

JMW
www.ViscoAnalyser.com

SomptingGuy (Automotive)

24 Apr 12 6:56

That's got to be a simulation prediction, not physical.

- Steve

hemi (Automotive)

24 Apr 12 18:50

Quote (jmw):
BSFC #s ?
Sorry, I'm not from the texting generation.

BSFC values (numbers) - not really texting generation usage here.

jmw (Industrial)

24 Apr 12 19:00

Sorry, no hash sign then.

JMW
www.ViscoAnalyser.com

GregLocock (Automotive)

24 Apr 12 19:20

Here's some numbers for other engines

http://en.wikipedia.org/wiki/Brake_specific_fuel_consumption

Cheers

Greg Locock

New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

SMOKEY44211 (Automotive)

24 Apr 12 20:17

I'm a little behind the curve when it comes to high tech. Just got a rotary dial cell phone.----Phil

patprimmer (Publican)

24 Apr 12 21:52

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930093158_1993093158.pdf

This report made in 1944 mentions BSFC as an acronym for Brake Specific Fuel Consumption. I think 1944 is well before the advent of texting.

I also remember using # as a symbol for number going back to mainframe computer days like the 1970s.

Regards
Pat
See FAQ731-376: Eng-Tips.com Forum Policies for tips on use of eng-tips by professional engineers &
http://eng-tips.com/market.cfm
for site rules

jmw (Industrial)

25 Apr 12 5:26

I'm digging my foxhole a little deeper now folks. wink

JMW
www.ViscoAnalyser.com

140Airpower (Automotive)

4 May 12 17:46

This is a very ingenious idea, but it is complicated. It appears that there is 1 induction stroke, 1 compression stroke, 1 power stroke and 1 exhaust stroke for 2 paired cylinders per 1 revolution. This is the same as for any 2 cylinders of a 4-stroke engine. It uses only 1/2 the injectors and spark plugs.
However, it has only 1/2 the intake ports and valves and 1/2 the exhaust ports and valves and it looks like the durations of the intake and exhaust events are shorter than they can be in a 4-stroke. The intermediate port and valves are extra restrictions in the chain. It appears to me that the performance of the 2 coupled cylinders would have to be much poorer than for 2 cylinders of a 4-stroke. The BSFC should be higher also because of the added pumping losses in the intermediate port and transfer problems.
The conflict between induction of the pre-compressed charge into the power cylinder and the compression stroke at the same time and the timing of the spark with the induction port still open looks restrictive for induction, compression and spark timing, but only experimentation can tell if or how much of a problem this is.

Is this right? What am I missing?

BTW, the second intermediate valve won't seal well opening to the outside of the chamber. Why is that necessary?

malbeare (Automotive)

5 May 12 19:00

140airpower,
Elegantly and politely put . basicly this design in its present form has no future . Why not do away with the charging cylinder and add or substitute a turbocharged intercooled positive displacement supercharger (roots), The result would be better.

A tidy mind not intelligent as it ignors the random opportunities of total chaos. Thats my excuse anyway
Malbeare
www.sixstroke.com

SMOKEY44211 (Automotive)

10 May 12 19:30

Update. They are now posting BSFC numbers on their website. Looks like 233gr/Kwh with turbocharger. Malbeare I agree with your thinking. Looks like someone within the organization is starting to get it.------Phil

GregLocock (Automotive)

10 May 12 21:52

If you look carefully at those graphs they are simulations, not tests.

233 is a bit hohum, but I suppose you could argue it is good for a two stroke on gasoline, but then as two strokes go it is more of a 4 stroke.

Cheers

Greg Locock

New here? Try reading these, they might help FAQ731-376 http://eng-tips.com/market.cfm?

SMOKEY44211 (Automotive)

14 May 12 20:24

Good eye Greg. I failed to notice that.-----Phil

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Scuderi~Split Cycle Engine, anything to it?(2)

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