Singh Grooves
 

Searched but did not find.
Anything to this grooving stuff? The idea seems to be to channel unburned fuel towards the spark plug and break up standing vortices during combustion. Makes sense, I suppose.. but what about chamber integrity?
Somender Singh grooves in a Geo Metro!
SOMENDER-SINGH.com - Home

Thoughts?

Edit: further investigation reveals this thread at teamswift: http://www.teamswift.net/viewtopic.php?t=26432
Same guy.

Hmmm never seen theis before. Interesting I guess, might work BUT, I am sure it creates hot spots in the chamber and over the long run I bet it could crack like an SOB.

I am also sure that a concept like this is not so advanced that some combustion engineer at a manufacturer could not have come up with it.

Interesting. I would expect some cooling due to increased surface area. Taken further, the grooves could look like the "tree shaped" grooves that cutting boards had in them back in the 1960s to collect meat juice (like the skelaton of a fish with very few bones). Then maybe they would not have be as deep.

Yes more surface area will cool the combustion event more and where does that heat go? into the head where the surface area is, so there will be localized hot spots. Overall the increased heat transfer means less efficiency BUT, I am open minded to the posibility that this heat transfer can be more than offset by a more efficient burn if these groves actually work.

Tough to do an A-B-A comparison of a mod like this! :)

I had read an article quite a while ago (several years?) about this guy and his work in (I think) Popular Science. From what I can remember of the article:

He was working with cheap Indian cars that were crazy inefficient after spending years in motorsports. He managed to do some good stuff then just by grinding grooves in the headers. He also wanted to make more bell shaped combustion chambers. He went to several companies with the idea and the only one who gave him a shot was Briggs & Stratton and they only let him test the design on an old 2 stroke mower engine. At the end of the article he was to begin working with an actual car company.

Interesting to see what has become of this.

HERE'S THE ARTICLE

And it's from September 2004.

Modern Combustion chambers already promote swirl in the air flow with the focal point right around the spark plug. Cutting grooves in the combustion chamber face just lowers your compression, increases heat loss from the combustion gasses, and weakens your head.

Even on an older engine, this technique has been shown to do nothing to improve peak power or efficiency. I don't have the link, but someone sacrificed an engine and tested this on an engine dyno. It will move the rpm of your peak power and torque slightly however.

This is very interesting.....................

I found the experiment I was referring to RevSearch Engine Dyno; Grooves testing.

No real changes

Looks like it made slightly more torque in the usable rpms....
I notice that the test groove represent a much smaller % of the surface area than the multiple grooves per cylinder shown in the metro buildup pics. I wonder if they went as far as they should have?

I read this article eight years ago and just tracked it down. For some reason it cuts off. This page has the rest of the article:

Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - Singh Grooves

I found several websites where people are trying this on their vehicle, but like the Jeremah in the original post, all improvements are antecdotal.

Belongs in the Unicorn corral IMHO

I do not think that unicorns would appreciate you putting dimples on them.

tests and test results GEO Metro 10G
 

Been hearing about Singh grooves for years, and that's the first comprehensive test I've seen.

The guy that posted the link I shared earlier also ranted about that test. I usually ignore people who rant. I just remember he said that the test was worthless because they used the wrong cell. They did mention several times that the cell was a limiting factor, but it would have been prohibitively expensive.

I did not see an overall conclusion, just many tables and summaries after each series of tests. They certainly seemed thorough. I also do not remember anything about three valves compared to four or five. Did they say why it would not work.

What was the difference they showed in MPG and HP?

Why is this not in the unicorn corral? It's unproven and totally speculation.

Singh himself went to the trouble of having his modifications tested when he started out... But verification from Singh groove users is hard to find, especially as not many bother to really test them properly.

Always thought this was Unicorn stuff, myself, and probably not compatible with more modern multi-valve cars... Especially if you can't eliminate the effects of ECU relearning like these guys did by using a MegaSquirt.

The summary is before the tables. Lower fuel consumption and cooler operation in most conditions. I wonder, though, if it would have been better to do a "before" test for both engines... just to eliminate the effects of manufacturing variances which might cause one engine to naturally run better. But the preparation of the engines sounds pretty good, if they're telling e true, and they were pretty thorough, otherwise.

Strange that the wideband shows less oxygen in the exhaust and that the engine runs cooler even with less fuel being injected. Does the groove promote better burn by pushing the air towards the plug as the cylinder goes up?

documented improvement
 

" Why is this not in the unicorn corral? It's unproven and totally speculation. "
http://farm4.staticflickr.com/3432/3...05ef56c1_b.jpg

there is a documented improvement in fuel economy at a common load and rpm with that particular 10g engine , shown is a before and an after
same engine
before
and
after installing singh grooves
no other variable

upwards of 20% improvement at the same load - that is significant

it is not rational or accurate
to say that this improvement is un documented and pure speculation with this 10g engine -

read the test description - then read the test results
if your opinion at that time does not agree with posted facts
that is fine
run the test your self , post your test results , prove these posted test results to be
in accurate ... other wise these test results stand .

this is pretty neat. never heard of this before.

This is from memory alone from almost 30 years ago so take it with a large grain of old salt.

The Mercedes Diesel engines of the early 1980s passenger cars had grooves radiating from the prechamber. The idea of grooves radiating from the point of combustion, assuming my memory is correct, is at least 30 years old and possibly much older. I am not sure when Benz started grooving the area around their diesel prechambers, but apparently they were a useful part of creating turbulence in the combustion chamber. They probably also helped to reduce the Diesel knock typical of most diesel engines.

Personally I don't doubt Sing accomplished an improvement with his grooves. Turbulence in the combustion chamber helps to create a more homogenous mixture which according to research in Homogenous Charge Compression Ignition (HCCI) has the potential to improve mileage and efficiency by 25%, while reducing emissions to the point of elimination of any aftertreatment of exhaust gas. HCCI means the instant of ignition occurs throughout the combustion chamber versus ignition starting in a single spot and propagating through the combustion chamber.

My belief is that Sing "discovered" the effect long after it had already been utilized by manufacturers like Mercedes Benz and possibly others long before the example I saw personally when I worked at a dealership in Houston Texas in 1982. Naturally with crude engines of the type with archaic fuel delivery systems that Sing was working with the grooves would make a greater difference in turbulence, compared to more modern designs that incorporate turbulence as a basic part of their design, with modern fuel injection and feedback mixture control, the value of Sing's modification is greatly reduced and possibly eliminated altogether.

regards
Mech

Are we reading the same chart? I see different VAC, different TPS, different TQ, different HP (i.e. different load), and to me lower numbers are better for BSFC.

I read that these grooves can cause heads to crack.
It doesn't do much good if they work but cause your cylinder head to crack after 50,000 miles.

Unless you could keep your engine combustion chamber almost perfectly clean or at least very clean these grooves would likely cake up with soot. So unless you are running water injection any gains will be lost over time, rather quickly.

If these grooves were so effective then why haven't the OEMs picked up on it?
Apperantly Mercedes tried them at least for a little while and only used them once in production.
Pre-combustion chambers in general tend to be pretty cracktastic I would be hesitant to add more potential crack starting points.

On the chart, it says "4th gear 3000 RPM," so wouldn't that just mean that it isn't requiring as much fuel to be at the same point in the powerband after the grooves are created? I'm no engineer, so I could be completely misunderstanding that.

I am tempted to perform said grooves on my Austin Mini.
But then, the engine is 1959 technology so in this particular instance, it is possible it really helps.

Hypermilers generally do reversible modifications, so we can do ABA testing, and make sure that it works. Honestly, I feel that it is unproven, and I would hate for it to not work out for you.

So the other 4 tests I've read where the results showed a negative impact on power and fuel were what? :confused:

These "tests" are hardly scientific, they are being used on terribly in-accurate machinery.