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Old 11-08-2009, 07:36 PM   #11
blacksheep98
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Well I precieved that when advancing timing you are fireing off the fuel mixture at a more volatile state. see if the honda fires off the fuel at a pre determine point just before top dead center on the stroke that is your base line, if you advance it more than stock thus firing off the fuel in a more advanced manor you would be generating more space for tha air to fuel mixture to expand before hitting top dead center and this would allow a greater expansion of the fuel causing a hotter and more volatile combustion. The end result theroretically is a more efficient burn of the fuel/air mixture which in turn would generate more heat. This point seems mute though since I found my answer with the other members noticing no change in the fan coming on and off. Sorry for the motor head babble, Im an advid engine builder although be it for hot rods mainly big block chevy's
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Old 11-08-2009, 07:50 PM   #12
firefighter212
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You gotta keep in mind that the timing specs. are set from the factory for cleaner burning engines and not for performance,E.P.A. standards.Just like when you see the top fuel burning dragsters at the line.How much unburnt fuel you think is coming out of those headers?Alot more than you think.It`s all about performance and not the environment when it comes to H.P. from a race perspective.
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Old 11-08-2009, 08:59 PM   #13
mcvierh
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Increasing power output is the primary goal of all engine tuning. Understanding the equation that determines engine power output is very helpful.
Pb= ni nc nm nv pi Vd (N/X) F Q (ref: Engines An Introduction by J. Lumley, pp. 26)
where:
Pb brake power output
ni indicated efficiency
nc combustion efficiency
nm mechanical efficiency
nv volumetric efficiency
pi inlet air density
Vd displacement volume
N rotational speed (RPM)
X revolutions per power stroke (always 2 for a four stroke engine)
F fuel/air ratio
Q heating value of fuel





The engine builder determines some of these factors (an obvious one is Vd). Other factors can be optimized by the engine tuner. Let's examine each factor in more detail.
ni indicated efficiency is based on the pressure-volume relationships and heat transfer (losses) during the engine cycle. Compression ratio is a primary determinant. Octane requirements and the effect of compression ratio have already been discussed above. Heat losses are difficult to optimize and beyond the scope of the engine builder or tuner. AFR has an affect on gas properties (specific heats at constant volume and pressure) and thus a minor influence on ni that contributes to the shape of the torque versus AFR curve shown above.
nc combustion efficiency is the percent of fuel that is burned. The value is usually close to 1.00 (100%). Good mixture distribution between cylinders, high swirl, and optimum ignition timing influence nc.
nm mechanical efficiency includes all friction losses in the engine (and drive train for the case of chassis dyno measurements). "Blueprinting" an engine can reduce friction losses. Lower viscosity synthetic oils reduce viscous friction loses (the effect can be several horsepower). Windage and pumping losses associated with the crankcase and oil systems should also be considered. Gear drive camshafts have lower friction losses than chain drive arrangements. Evo style V-Twin engines have inefficient charging systems. Changing to a series regulator reduces high RPM alternator losses. Careful attention to all areas that influence nm can result in gains of a few horsepower with the additional benefit of reduced heat generation and fuel consumption.
nv volumetric efficiency is the actual volume of air inducted into the cylinder divided by the cylinder displacement. The value of nv can exceed 1.00 (100%) in a well tuned race engine by means of inertial (ram) and resonant effects within the intake and exhaust systems. Head design, including valve size and port shape, and camshaft characteristics greatly affect nv. Modifications that affect nv are the traditional realm of the experienced engine tuner and can result in significant power gains.
pi inlet air density is a function of pressure and temperature. A restrictive air cleaner or throttle body reduces inlet air pressure. Excessive heat transfer from the intake system increases inlet air temperature and harms performance. While so called "cold air intakes" are commonplace in the sport compact marketplace, inlet air temperature effects are usually overlooked by V-twin engine tuners. The effect is significant as a 20 degree C (36 degree F) rise in inlet air temperature results in a 6% power reduction.
Vd displacement volume is the most basic engine parameter and has a direct effect on engine power.
F fuel/air ratio is the inverse of air/fuel ratio (AFR). The effect on power is somewhat more complicated than the equation suggests. The effect is only linear for lean mixtures (above 14.7 AFR) where excess air remains and all the fuel is burned. The lean part of the torque versus AFR curve shown above is where the equation applies. For performance applications, engines are always run rich. Additional fuel cannot be burned due to lack of air and the torque curve levels off and then starts to drop at very rich AFR values.
Q heating value of fuel, i.e. the energy released when a given mass of fuel is burned. Q is varies slightly with different grades of gasoline (regular 87 octane is about 42.7 MJ/kg, premium is about 43.5 MJ/kg, and fuels blended with high levels of MTBE and/or ethanol have lower heating values).




From a practical standpoint, engine power output is most readily increased by increasing the displacement volume and volumetric efficiency. Additional increases can be obtained by selecting the maximum compression ratio (about 10.5:1 for 93 octane gasoline) and careful attention to details that increase mechanical efficiency and inlet air density.
Engine control systems can only affect ignition timing and AFR. These parameters are optimized by setting ignition timing to a value near the detonation limit and AFR within the range of 12.5-12.8 at WOT. Further tuning efforts involving small changes in ignition timing and AFR generally fail to yield measurable improvements.

With that said, your engine will run cooler advanced 4*.




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Old 11-08-2009, 09:02 PM   #14
firefighter212
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Good post Mel,god love ya!!!!!!!!! lol
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Old 11-08-2009, 09:23 PM   #15
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Heres some more food for thought.
The MBT (Makes Best Torque - optimum) ignition timing for the style of each spark plug IS different.
If you were to to test spark plugs, using the geometry as the variable, and matching ignition timing for each geometry type, you will probably find that, as we did with the 4 Gas EGA EC997 dyno, that:
Spark plugs with "retracted and surface gap" style as compared to "extended tip" styles, require more ignition lead / advance to make best power.
Spark plugs with "projected / extended tip" electrodes require less ignition lead to make best power.

In other words - if you place the spark closer to the middle of the combustion chamber with a "projected tip" spark plug you will need less time (ignition advance) to reach peak cylinder pressure. That's a good thing.
Why?
With an "extended tip" style plug, as the piston is rising on the compression stroke, you will generally find that you will start the "burn" later for MBT setting - decreasing the amount of time that you are burning, heating and expanding the trapped air and fuel as the piston is still going up. Any pressure that is created as the piston is coming up to Top Dead Center tries to push the piston back down - subtracting power from the total amount of power produced on the following power stroke. This is IMPORTANT!

Soooo...... in general:
You want to build / tune an engine to have the quickest burning, most efficient combustion chamber.
Use a spark plug that requires the least amount of ignition lead for best power.
Use a fuel that has the quickest possible burn rate, without detonating, so that you end up using the least amount of ignition lead / advance for best power.

That will produce best power.
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Old 11-08-2009, 09:35 PM   #16
mcvierh
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God sometimes them n0obs just piss me off...especially them that "build engines" and don't have a clue what the fuck their putting together........
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Old 11-08-2009, 09:40 PM   #17
firefighter212
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Sometimes the grease fumes go to their head and they are in la-la land.lol
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Old 11-09-2009, 12:49 AM   #18
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hehehe...and I quote...
God sometimes them n0obs just piss me off...especially them that "build engines" and don't have a clue what the fuck their putting together........
Today 08:23 PM





hehehehe...love the stone on a Sunday evening chillin whichu guys.
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Old 11-09-2009, 10:11 AM   #19
blacksheep98
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Quote:
Originally Posted by mcvierh
God sometimes them n0obs just piss me off...especially them that "build engines" and don't have a clue what the fuck their putting together........

Unfortunatley for you I know exactly what im building when I refer to the engines I build, Ive put almost 50 engines on and engine dyno and have seen what results for paticular tunning and as a fact Ive seen hotter exhaust port temps from advanced timing. Now I know this from experence not something I googled a posted as such seen above. Although it is correct it is by far more advanced than ever needed for most.
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Old 11-09-2009, 10:23 AM   #20
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...oh n0ob...oh no n0ob...


maybe you should use the search button and just type in Mc's name...


and I would be willing a wager that he didnt google any of that, and even if he did, it is probably from a site that HE set up.

I tried that "suck my dick Mcvierh" shit when I first started posting too, but mine was morphine and hydrocodone influenced...when I STFU I realized that he is prolly one of the smartest mutherfuckers on this site when it comes to these Shadows ...

So n0ob, I PERCEIVE that you brought this on yerself, and I HOPE that you will stfu and listen to the man...

BTW...I own an ACE like yours, was wondering if you had considered a weld on or bolt on hardtail as opposed to the struts?

Its all good man.
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