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Opeler
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18 Posts
Discussion Starter · #1 ·
Hi all,

The manual shows that the timing of a standard 1900 cc engine should be set at top dead centre. However, I have a Fuel Star fitted to my engine and it seems that you can easily set it at 8 degrees before top dead centre and it still does not ping. It idles a lot better as well. What ignition setting does your car run on?

My car is 1900cc, it has the flat top pistons fitted, hardend valve seats, electronic ignition with standard points, fuel star and no further modifications.
 

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Old Opeler
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5,564 Posts
Fuel Star

A fuel Star is a snake oil gizzmo that fits into the fuel line and has little cones of tin in it to "condition" the fuel so that 10:1 CR engines can run on regular no-lead fuel - without pinking!

Strangly enough they seem to work!!??

Hi Cees, just type Distributor in the Search Box and lots of info on advance and advance curves will appear.

THe early 9:1 CR motors used more advance than the later low compression ones.

9:1 CR 32 to 36 crank degrees advance in the distributor with a total of up to 38 to 42 dgrees advance - 2 to 10 degrees initial.
Though they are set up at O degrees initial and Rally Bob's article in the Technical Library mentions, from memory, best power at 32 to 36 degrees total (check his article) - without vacuum advance being taken in to account.

Low CR about 4 to 6 degrees less, mainly for emissions reduction.

Just make sure it does not detonate under load.:(
 

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Opeler
Joined
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18 Posts
Discussion Starter · #4 ·
Thanks Jim, your explanation of the fuel star is correct. Although I have hardened valve seats fitted to my engine I still decided to fit a fuel star. This unit is also recommended for modern cars, as the manufacturer claims it will save you fuel. independent tests in Australia indeed showed a fuel saving of between 5 and 12 %. I also do not quite understand how this comes about. There are various brands [and different sizes] on the market and they are all guaranteed to last 100,000km.

Have you done any work on your car Jim, now it is freshly painted?


Cees
 

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Old Opeler
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5,564 Posts
No Advance!

Since the later Low compression cars have less advance in the distributor it may be possible to use a '72/'73 distributor with greater initial advance so that total advance does not exceed the best power setting. It is said that the automatic trans engines have a "quicker" curve for better acceleration.

Just have to watch detonation in the mid-advance rev ranges on hard acceleration as the peak cylinder pressures would occur at this time in the peak torque rev range. The more efficient the cylinder filling ( porting/bigger carbs/extractors/cam etc) the more likely things will get too high pressure somewhere and knocking will start.
Overheating doesn't help either!

I am sure there are people out there in the USA race/rally scene who have done lots of experimenting with this topic.

Not a lot happening with my GT yet as the Bathroom restoration had to be completed for Christmas - payback; you know how it is!
 
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