Singh grooves in cylinder head

[Torquemonster]

The testing has been focused around fuel consumption reductions - which we are getting good results on.

For giggles we decided to test emissions as well and were pleasantly surprised at the gains there -

so to answer your question again - yes - if the fuel is burned more efficiently - emissions clean up at no cost to power.

If we have learned anything from Smokey Yunick and Larry Widmer; the ICE as we know it leaves plenty of room for improvement in the areas of efficiency and performance.

Can you tell us what air/fuel ratio you are running?

15.2:1 according to the emissions test at 3000rpm steady.

See that's the interesting thing - we have not even started remapping yet. Yet just letting the stock ECU do it's thing - the car way more than doubled its economy at cruise. Cruising at 100kph now requires breathing on the throttle compared to before

Trust me - if we can get this concept to work on the track - you'll hear about it because we want to see less oil burned and cleaner air....

[Twinscrew]

15.2:1 according to the emissions test at 3000rpm steady.

How can you run leaner than stoichiometry yet make more power? What is the theory?

[lil289]

automotive breath,

In your research, have you discovered if the engines respond to less spark advance? It would seem if the mixture burns faster and more thoroughly that less advance would be required, resulting in less negative work, more power, etc.

Thanks

[jackdaniels]

Quick question to anyone,,
Im from Guatemala, as some know already,
And I mention these because, how must i direct a machine shop person or describe exactly what to do.
There are not very experts in machining parts in Guatemala as here, or as some of you have a lot of experience on race engines or are machinists yourselves.
My question is, if i want this to get done on Guate.. How do I ask for ir???
does the dimentions of the groves have to be some specific type?
the direction, length, and the "deepness"?
i realy liked this thread and would like to use this method on an engine some time, just that i wouldn know how to ask for something people dont know what it is...
Thanks everyone
Daniel

[Torquemonster]

15.2:1 according to the emissions test at 3000rpm steady.

How can you run leaner than stoichiometry yet make more power? What is the theory?

1 - the engine will no doubt run richer as soon as load demands it

2 - it can make more power while running leaner because it is putting more fuel to work and less goes out the exhaust.

There's enough energy in a gallon of gas to send a car almost a mile into the air if you could harness 100% of it. By vaporizing the fuel better - you get more for less - simple as that.

Say your engine now puts 28% of the fuel it burns to work. If that improved to 33% - you'd get more power on the same gas, or same power on less gas.

In a max effort engine you will lose some intercooling impact - so therefore the vapor improvement has to out weigh that loss to give a net power gain. In a street car - the improvements are right across the rpm range.

[mudracer]

So this idea might be better suited to an engine that has a large amount of area "under quench" as opposed to a large combustion chamber, am I correct?

I also assume, *(because Im good at assuming) that a long stroke would help to bring the piston speed up to help stir the air at top dead center.

Let me know if Im wrong here.

So, with that info... I could use say, a 500 caddy engine for a test mule, because its got a reasonably small chamber with a reasonably large bore, and a long stroke, right? 4.304x4.30, according to the book. If the deck was set at .005, and a .049 thickness gasket used, the quench wouldnt be too excessive, I hope. This setup might be an example on the extreme, though. Would too small or too large an engine give you a skewed number? Or would the design of the chamber limit your power ability?

If you were to use a cylinder head design with very little quench area, like the 455 pontiac stock cylinder head design with barely any quench, would you get any results of value?

Figured I would just ask that. Ideas?

I take it that this idea has not been used on a max effort racing engine due to the inherent loss in parts should it not work.


sorry if i dont make a lot of sense here. Im just thinking in print.

[automotive breath]

These grooves sound promising. My confusion is on
the jaguar 12 cylinder, the May head raised the compression and power
by having a small chamber around the exhaust valve. I know it has
limitations, but it worked better than the old flat deck head (efficiency
wise). Does anyone have an opinion on grooving the May heads? I have
considered doing this as that is the point where my Jag is at right now. I
am trying to get more efficiency out of it. Any suggestions?

Thanks,
John

Hi John,
If you are serious about this I'd like to get involved, I have ideas that could prove to be useful. What are the limitations you mention?

[automotive breath]

automotive breath, In your research, have you discovered if the engines respond to less spark advance? ....Thanks

lil,
The engine that I'm using for testing now is a flat top 355 with unported topline 50cc combustion chamber iron heads. It's a mild bracket engine designed for consistency. I put the engine in the car two years ago unmodified for base line tuning; the heads have been off twice for modifications.

The ignition timing is 6 degrees lower now than it was when I put the engine in the car. The ET is on average 0.20 seconds quicker and two MPH faster now. This is the most consistent bracket engine I have ever run.

*************************************************************

I post pictures of high compression SBC engines. I don't run these; they belong to friends. Running compression ratios in excess of 13.5:1 they run high octane fuel that burns slowly. I don't tune these engines, they tell me they run best with 42 degrees advance. That's what I would expect them to run unmodified, so I don't know. Again, I don't run high compression engines and I'm not doing the tuning.

[automotive breath]

so, conceivably, some redneck like me could get the grinder out, cut some grooves in some old cracker heads, and *( IF i get it right, and thats a BIG IF) make more power and get better mileage?...
..

Let me know what old heads you want to try, I'm give you my thoughts, try to help you get it right.

[Mike Moore]

We build racing engines for airplanes, yes airplane racing just like NASCAR. The props limit the engines to relatively low RPM on direct drive engines, usually less than 3000 RPM, most are less than 2700. Most of these incorporate true hemispherical chambers and piston domes, low compression, 9:1 and less for turbo's, and fixed timing, around 24BTDC. We can already get B.S.F.C.'s of .40 and less, down to .38 lean of peak (LOP). I dont know how one could get an A/F of above 15:1, but I would sure like to learn.

Anyone incorporate these grooves in a hemispherical head, like a Chrysler or a two stroke? Parts are so expenisive, I cant afford to groove up a set of jugs and not have it work. It looks like a potential stress riser too. Our firing pressures are around 1200psi on a stocker and over 1400psi on a turbo. With 5.25 inches of bore, that is a ton of force.

Anyone??

[panic]

Vizard reports using ratios as lean as 28:1 with very high vacuum advance.
Why does this work?
As long as the mixture can be lit - wide gap, high voltage, short voltage rise, etc. - extra air is no more "wrong" than the 79% nitrogen already present. Remember: 14.7:1 etc. is the percentage of air vs. fuel by weight, the percentage of oxygen vs. fuel is much higher - about 3.5:1 for octane.
The cylinder is a pump, but the working fluid isn't air/gas mixture, it's anything in the cylinder, including oxygen, fuel, nitrogen, argon, water vapor (this is why water injection can add both power and mileage). Combustion has a single purpose: raise the temperature of the working fluid.
Extra air raises the effective compression (not the ratio) by increasing mixture density (more molecules present), and reduces pumping loss because the throttle opening must be greater for the same power (lower manifold vacuum = lower pumping loss). Any fluid could be used, but air is available and already being metered (extra nitrogen alone might be better but not as easy).
Since all the fuel is used, the additional oxygen is only working fluid instead of a combustion component, then it becomes an exhaust product - the same as the 79% nitrogen is now - working fluid released after doing its work.
The downside: the mix only develops 65-70% of available power (90% @ 16:1, 80% @ 20:1), requires lots of timing for the slow burn, etc.

[MadBill]

One of the most relevant results of what Panic is saying is that leaning out the mixture from LBT only raises temperatures up to a certain AFR, dependent on various combustion factors. Thereafter, the air is effectively inert, having no fuel left with which to react. A simple example of this is NOx production, which is very temperature sensitive. Leaner than ~ 16:1, engine-out NOx production drops off, since combustion temperatures decline past the point at which 100% of the fuel is consumed, due to the lower fuel mass and the greater 'inert' air mass now present.
Another good example is an alky engine. Numerous racers have encountered the distressing situation of richening up a suspected lean mixture, only to melt down the engine due to the increased heat release from the greater mass of combustible fuel in the still-too lean mix.

[automotive breath]

... A simple example of this is NOx production, which is very temperature sensitive. ....

That’s exactly how gas fired turbines control NOx, they lean the mixture to a point just before flame out, that’s where the lowest flame temperatures and NOx emissions can be found.

air:fuel | E ratio | flame temp.
11.7:1 | 1.26 | 1968
12.7:1 | 1.16 | 2047
13.7:1 | 1.07 | 2114
14.7:1 | 1.00 | 2122
15.7:1 | 0.94 | 2071
16.7:1 | 0.88 | 1996
17.7:1 | 0.83 | 1926