" Why is this not in the unicorn corral? It's unproven and totally speculation. "
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 .
The Following User Says Thank You to mwebb For This Useful Post:
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.
upwards of 20% improvement at the same load - that is significant
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.
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2016: 128.75L for 1875.00km => 6.87L/100km (34.3MPG US)
2017: 209.14L for 4244.00km => 4.93L/100km (47.7MPG US)
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.
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1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white, portable 240v CHAdeMO, trailer hitch, new batt as of 2014.
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.
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.
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