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Old 30 May 2012, 05:02   #21
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Couple of questions for you who seem to be so clued up on the petrol front because I am intrigued! Is RON the percentage octane level of the fuel? Or is it some other measure? Because octane itself is aliphatic of course and the companies refine these to produce branched and cyclic isomers which promote efficient combustion but would not be called octane despite having 8 carbons. Also, how can ethanol increase the RON if it is a measure of octane, or is RON nothing to do with the level of octane rather a measure of the energy density of the fuel?

The biggest problem with ethanol on boats is storage of the petrol in the tanks. If left for long period (eg winter) condensation within the tank is a much more serious problem. Cars are much less likely to be stood for extended periods of time as boats are so the problem does not exist.
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Old 30 May 2012, 06:06   #22
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Injector Failures

As I understand it the reaons injectors fail on E-tecs come down to the following:

Problem - Particles in the fuel leading to the injector filter screen getting blocked
Symptom - Engine runs rough will not hit top RPMs and hole shot is affected sometimes the injector "ticks" loudly as it is starved of fuel.
NB - The warning buzzer will probably not go off for this fault and no fault coded would be present.

Problem - Injector suffers corrosion through water in the fuel. Even a small amount of water in fuel can cause problems particularly if the engine is not used for long periods and the water just rests in the injector.
Symptom - As above however the injector will likely not tick any more as it bolloxed.

Problem - Injector suffers internal electical failure of the coil
Symptom - The engine will throw up a warning code and the engine will go into limp home mode. This does happen although unlikely to happen until engine is heading for 1000 hours, there have been some issues with bad batches of injectors in the early days however these were resolved. Unfortunately the odd injector does fail.

It is worth noting that for blocked injectors if corrosion is not the cause then there is a process that can be done quite simply to clean the injectors however not everyone is that keen on getting their hands dirty !..
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Old 30 May 2012, 07:17   #23
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Originally Posted by gotchiguy View Post
Couple of questions for you who seem to be so clued up on the petrol front because I am intrigued! Is RON the percentage octane level of the fuel? Or is it some other measure? Because octane itself is aliphatic of course and the companies refine these to produce branched and cyclic isomers which promote efficient combustion but would not be called octane despite having 8 carbons. Also, how can ethanol increase the RON if it is a measure of octane, or is RON nothing to do with the level of octane rather a measure of the energy density of the fuel?

The biggest problem with ethanol on boats is storage of the petrol in the tanks. If left for long period (eg winter) condensation within the tank is a much more serious problem. Cars are much less likely to be stood for extended periods of time as boats are so the problem does not exist.
1/. Octane rating does not relate to the energy content of the fuel. It is only a measure of the fuel's tendency to burn in a controlled manner, rather than exploding in an uncontrolled manner. Where the octane number is raised by blending in ethanol, energy content per volume is reduced.

(simplistic description)
Research Octane Number (RON)
The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing the results with those for mixtures of iso-octane and n-heptane.
Motor Octane Number (MON)
There is another type of octane rating, called Motor Octane Number (MON), or the aviation lean octane rating, which is a better measure of how the fuel behaves when under load, as it is determined at 900 rpm engine speed, instead of the 600 rpm for RON.[1] MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern gasoline will be about 8 to 10 points lower than the RON, however there is no direct link between RON and MON. Normally, fuel specifications require both a minimum RON and a minimum MON.

2/. Correct about storage, any water will lower the boost from ethanol in both octane, rvp and vli. (typically 4-5 rvp at 5% ethanol. this is further complicated by the denaturant used in the ethanol prior to blending)
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Old 30 May 2012, 10:06   #24
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Quote:
Originally Posted by gotchiguy
Couple of questions for you who seem to be so clued up on the petrol front because I am intrigued! Is RON the percentage octane level of the fuel? Or is it some other measure? Because octane itself is aliphatic of course and the companies refine these to produce branched and cyclic isomers which promote efficient combustion but would not be called octane despite having 8 carbons. Also, how can ethanol increase the RON if it is a measure of octane, or is RON nothing to do with the level of octane rather a measure of the energy density of the fuel?
I believe that running the fuel through an aliphatic catalyst, with a dilithium doping agent will
Increase the octane rating as it raises the theta particulate density. This only applies in the Delta quadrant of course, as theta enrichment was banned in the alpha quadrant by the kittemer accord.
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Old 30 May 2012, 10:54   #25
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Outstanding
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Old 30 May 2012, 11:06   #26
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Quote:
Originally Posted by Pikey Dave View Post
I believe that running the fuel through an aliphatic catalyst, with a dilithium doping agent will
Increase the octane rating as it raises the theta particulate density. This only applies in the Delta quadrant of course, as theta enrichment was banned in the alpha quadrant by the kittemer accord.
Finally someone who can explain it in easy to understand terms! Thanks PD
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Old 30 May 2012, 11:50   #27
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I believe that running the fuel through an aliphatic catalyst, with a dilithium doping agent will
Increase the octane rating as it raises the theta particulate density. This only applies in the Delta quadrant of course, as theta enrichment was banned in the alpha quadrant by the kittemer accord.
'Scotty' tried it but it didn't work on the 'Enterprise'. Of course he was immediately arrested by the inter galactic federation for breaking the accord!
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Old 30 May 2012, 11:55   #28
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Originally Posted by wellhouse

'Scotty' tried it but it didn't work on the 'Enterprise'. Of course he was immediately arrested by the inter galactic federation for breaking the accord!
Bilges here we come,
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Old 30 May 2012, 13:09   #29
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[QUOTE=Pikey Dave;465181]I believe that running the fuel through an aliphatic catalyst, with a dilithium doping agent will
Increase the octane rating as it raises the theta particulate density. This only applies in the Delta quadrant of course, as theta enrichment was banned in the alpha quadrant by the kittemer accord.[/QUOTE AV AN ORANGE OUT THE BOX SON
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Old 30 May 2012, 14:40   #30
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Quote:
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an aliphatic catalyst,
Do you know what aliphatic means...
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