Shell Optimax (Super Unleaded)

[Badobsession (the real one)]

#thumbs_up# Totaly agree, the fuel companys want your money and will do anything to get it including adverts trying to get you to buy expensive fuel which does nothing worthwhile.

[hypojam]

phill50 said:

its all in your head !!!
high octane fuel will only allow you to run a higher compression ratio without detonation, since the 50 only has a 6.5:1 cr it could run on the old 2 star fuel with no effects. actually f1 teams and bike race teams run as low an octane fuel as they can get away with without detonation as it gives better performance

Supposedly the Compression ratio is 10.5: 1 .
Is that a high compression ratio for an engine?

[phill50]

these are the specs from the taishan website , although the pdf boatian manuals list it as u correctly say 10.5:1 , would think 6.8:1 is more likely as 10.5 is more like a reasonable state of tune bike or high performance car .
not that it matters they are slow and avgas would make no difference let alone optimax !!



Engine Type - TSE41QMB

Diameter x stroke - 41x37.4mm

Cylinder Working Volume - 49cc

Compression Ratio - 6.8:1

Ignition Type - C.D.I.

Gov. Power/Revs - 2.3/6500/r/min.

Max. Torque/Revs - 3.5/5500/r/min.

Max. Speed 30mph (gov removable)

Clutch Type - Auto Centrifugal
#whip# #whip# #whip# #whip#

[warlock]

What about putting some Redex in every now and again..would that help?

[cb50j]

don't know if redex would make any difference

taishanowners.proboards41.com/index.cgi?board=chat&action=display&thread=1148648014

........C

[civvy]

Well since i do a bit of drag in an 87 Crx i think i'll give my 2p,
The Engine runs cooler for one
I can run more ignition advance
I can run a leaner fuel/ air mixture
Each of these three factors prolong engine life and increase mpg.

I would recommend the Tesco 99ron or BP Ultimate 102ron, however, its an unlikely bet that it won't make any differnce to an engine that has manual management.

Unless you know what your doing ;-)

[enu06]

Redex in moderation will help to keep your carb and valves clean, so it has limited use. No point in using it all the time though.

[px166bajaj]

Well, I dunno what it is about Shell petrol, but I've always noticed a certain "oomph" after filling up with it, with bikes and cars/vans. My Dad, (who has been driving since the 1940's, and still is, at the age of 88 (if you live near Whitstable in Kent, avoid little green Vauxhall Agilas!)) said that this discussion always used to rage in the old days of motoring. Pepole used to say that Esso was the best in those days, as it was American. "Power" petrol was the worst and cheapest because it came from the Russian oilfields.

[enu06]

Any one heard this? Apparently if you squirt Redex in through the plug hole onto the piston, it will decoke the piston for you, if your vehicle has done enough miles to need it. Dont know how long you leave it to soak for though!

[civvy]

yea, an old skool trick, somepeople used to put it in their oil too. but that was when you used to buy a penny shot at the pump. and good old lead was being used!

I understand peeps having a religion like yours and your redex and thats fine but with all the technology in the fuel and oil today, additives are a very expensive for what difference they make.

Have to report my scoot prefers Sainsbury's 97ron to Optimax and i've had to put my airbox back on since i was sucking up water through the K&N8(

[larry8]

tried Shell one time but it gave me the runs.

[sunburnspain]

How time & technology has moved on.
My Dad (RiP), used to tell me that in the War they used to p**s in the tank to make the petrol go further.
No Redex then, more like Red Barrel (I really am showing my age now)

[jialing]

Re: Shell Optimax (Super Unleaded)
« Reply #64 on Today at 3:22pm »

--------------------------------------------------------------------------------
tried Shell one time but it gave me the runs.

Its not designed for human consumption no wonder you got the runs :-)

[larry8]

Yah I know that NOW (but I did run around the block a few times before I ran out of gas).

[mauiscoot]

Octane boost or a higher octane will make any engine run better, cooler and a little faster. I put octane boost in my scooter every other fill up and I do notice a difference in speed and in milage. The one I use is made with jet fuel in it. When I bought my scooter 25 mph was the max speed, now I can do 40 mph. No not all from the octane boost but a increase of 5 mph when I started using it. I also re-jetted the carb., put a free flow air filter and changed the CDI money well spent. Next thing going on is a HOT COIL to go with the Race CDI. Hotter spark=more torque.

[jialing]

maybe you didnt see the notice forums closed..... moved to chinesescoots.forumwise.com

[mopo]

To stop this sharlatanism once and for all!!

How is gasoline made? What are octane ratings?
Gasoline consists of a complex mixture of hydrocarbons. Most of these are alkanes with 4-10 carbon atoms per molecule. Smaller amounts of aromatic compounds are present. Alkenes and alkynes may also be present in gasoline.

Gasoline is most often produced by the fractional distillation of petroleum, also known as crude oil (it is also produced from coal and oil shale). The crude oil is separated according to different boiling points into fractions. This fractional distillation process yields approximately 250 mL of straight-run gasoline for each liter of crude oil. The yield of gasoline may be doubled by converting higher or lower boiling point fractions into hydrocarbons in the gasoline range. Two of the main processes used to perform this conversion are cracking and isomerization.

In cracking, high molecular weight fractions and catalysts are heated to the point where the carbon-carbon bonds break. Products of the reaction include alkenes and alkanes of lower molecular weight than were present in the original fraction. The alkanes from the cracking reaction are added to the straight-run gasoline to increase the gasoline yield from the crude oil. An example of a cracking reaction is:

alkane C13H28 (l) --> alkane C8H18 (l) + alkene C2H4 (g) + alkene C3H6 (g)

In the isomerization process, straight chain alkanes are converted into branched chain isomers, which burn more efficiently. For example, pentane and a catalyst may react to yield 2-methylbutane and 2,2-dimethylpropane. Also, some isomerization occurs during the cracking process, which increases the gasoline quality.

In internal combustion engines, the compressed gasoline-air mixtures have a tendency to ignite prematurely rather than burning smoothly. This creates engine knock, a characteristic rattling or pinging sound in one or more cylinders. The octane number of gasoline is a measure of its resistance to knock. The octane number is determined by comparing the characteristics of a gasoline to isooctane (2,2,4-trimethylpentane) and heptane. Isooctane is assigned an octane number of 100. It is a highly branched compound that burns smoothly, with little knock. On the other hand, heptane is given an octane rating of zero. It is an unbranched compound and knocks badly.
Straight-run gasoline has an octane number of about 70. In other words, straight-run gasoline has the same knocking properties as a mixture of 70% isooctane and 30% heptane. Cracking, isomerization, and other processes can be used to increase the octane rating of gasoline to about 90. Anti-knock agents may be added to further increase the octane rating. Tetraethyl lead, Pb(C2H5)4, was one such agent, which was added to gas at the rate of up to 2.4 grams per gallon of gasoline. The switch to unleaded gasoline has required the addition of more expensive compounds, such as aromatics and highly branched alkanes, to maintain high octane numbers.Gasoline pumps typically post octane numbers as an average of two different values. Often you may see the octane rating quoted as (R+M)/2.One value is the research octane number (RON), which is determined with a test engine running at a low speed of 600 rpm. The other value is the motor octane number (MON), which is determined with a test engine running at a higher speed of 900 rpm. If, for example, a gasoline has an RON of 98 and a MON of 90, then the posted octane number would be the average of the two values or 94.

High octane gasoline does not outperform regular octane gasoline in preventing engine deposits from forming, in removing them, or in cleaning the engine. Consumers should select the lowest octane grade at which the car's engine runs without knocking. Occasional light knocking or pinging won't harm the engine, and doesn't indicate a need for higher octane. On the other hand, a heavy or persistent knock may result in engine damage.

[Ginger Phil]

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