Hi all

I know this has been discussed previously, but I ran a search and it looks like it has been cleaned out.

I have a 1977 Datsun 1200GX.
In South Africa I have heard last night that in 2005 leaded fuel is going to be phased out and by 2006 only unleaded fuel will be available.
My questions:

1. If our unleaded fuel are not compatible with my engine.What damage will it cause.
I do not want to remove my head now to prepare it for unleaded.
I rather want to keep driving it until the valve guides are worn and then convert the head to be able to handle unleaded.
Is only the valve guides going to get damaged?
What simptoms will my datto have to show me this occurince.
2. Those of you running unleaded, did you have to reset the timing?
3. Catelitic converter.
I have talked to lots of exhaust shops here and no one is using catelitic converters here.
One guy said "we just take them off and cut the sencor's wires that are plugged into them".......WHAT AN ASSHOLE!!!!!
My dad drives a 1995 volvo 850 and did some research for when his exhaust goes and this was one guys answer.
Someone else said they butchered one open when it was removed and saw it looks like a normal exhaust.
They just put in another exhaust box and drill a hole in it for the sensor.

I know our datsuns don't have sensors.
Must I then just put on another silencer?
thanks

> 2. Those of you running unleaded, did you have to reset the timing?

No.

> 3. Catelitic converter.
???

It might be best if you check the South African government web site (or local forums) and see what they are saying. A lot of this depends on what the government requires of the car owner, and what the government will require of the fuel suppliers.

If your unleaded is the same as the US, NZ and Australia then you won't have a problem with your valve guides at all. As long as your timing is correct and the engine isn't pinging then your head will be undamaged by running unleaded. I have never run leaded in an A series and have never had a problem with valve recession. I have driven 850k's a week for the last 2 years using a standard A14 with absolutely no fuel related problems. Except maybe the time I pulled on the choke and the linkages went inside out and she revved to 10000 before i shut it off.... That was kind of fuel related.

I think the unleaded will eventually mess up the valve seating surfaces. I'm not sure though.
The catalytic converter reduces unburnt hydrocarbons in the exhaust to water and carbondioxide. It's not a "muffler" although it does muffle the noise a bit. If your car was not designed with a cat then I don't think you'll be required to add one.
Don't worry about it to much. You and your Datsun will live. They got rid of leaded fuel here in California many years ago. They eliminated 92 octane about a year ago, too.

If your country adopts the same rubbish that NZ has got, then boo hoo for you. Your datto should be fine on it, however the stuff we get is crap. Our alleged 96 octane is tripe, leave your car sitting for a week or two and the octane drops to buggery. Plus, forget about running a grey pipe. All my cars run a black one since we lost lead. sigh My blown A14 pings bad at full throttle unless I dope the fuel with avgas.

Like dd said, it depends on the local government for requirements, but if it wasnt fitted with one, then its unlikly that you will need to fit one. Also since the a series has an alloy head, the valve seats are already hardened they are not going to be affected like the traditional cast iron heads.

Running a higher octane fuel doesent hurt, but not essential.

Hi guys, I had a A12 rebuilt a few months ago and my first question was that I want to run on unleaded my bloke said no prpbs the 1200 already has "steel valvle seats"and he said although it is called unleaded it still contains a percentage of lead.
I ran this car with the fresh motor for about 5 thousand k's and did not have a drama.
Ade

Many older engines with iron heads simply had the valve seats cut directly into the casting. The Tetra -Ethyl Lead that was used to slow down the rate of combustion of the fuel [thereby raising the octane] also laid down a coating of lead over everything in the conbustion chamber.

Most importantly, it coated the exhaust valve & the exhaust valve seat. This acted as a lubricant & protected the seat from harm & it's a system that worked a treat. Unfortunately, the lead that made it to the atmosphere was causing serious brain [intelectual] impairment to small children in urban areas. [Now you know why i live in the bush] Lead had to go as the social price was too high.

If one of these older engines is operated without the leaded fuel, the protective layer is steadily eroded away untill the glowing red hot valve comes into contact with the now unprotected valve seat directly. It then welds itself to a few microscopic grains of metal & rips them from the valve seat. This tiny bit of metal is blown into the exhaust system by the searing flame on the exhaust stroke.
This goes on & on for months or years, depending on usage & steadily the valve eats it's way into the head. This is called valve seat recession. With solid lifter engines, you will need to constantly adjust the tappets as the gap will be steadily closing up.

If the valve, & more importantly, the exhaust valve seat are made from a suitable material, there is no problem, & please note, unleaded fuel has NOTHING to do with valve guide wear.

You will NOT need a catalytic converter. The converter does what it's name says. In the presence of a catalyst, some of the bad air in the exhaust is converted into less, or non toxic output. This happens at high temperature, which is why they are located near to the engine.
The converter is NOT a silencer, although it does tend to moderate exhaust volume somewhat. This is just a spinoff of the design

You can not legally remove a catalytic converter from a car that was equiped with one from the factory, here in Australia.

The sensor you speak of is part of the EFI system, so there is no need to fit one, unless you are going to run an EFI system that uses it.

The timing will NOT need to be reset, unless the octane rating is low & you experience detonation problems [pinging] This would hold true of any kind of fuel.

I am thinking of using a specific petrol company here in South Africa.
They have recently launched a new unleaded petrol.
They are advertising that their fuel are direct injection compatible.
This does not have efect on me of course.
BUT. They also state that they have stuff in the fuel that they call "lead replacements" and also state "can be used by most cars that use leaded fuel".

Hopefully they did research on the problem that I will have if I use normal unleaded fuel.

Thanks for the info Dodgeman.
Something else.
If the valves do grind away steadily as you have mentioned at the valve guides due to no lead to protect it, wil it cut so deep that it will get to my GX head's aluminium?
Or is the valve guides too thick so that I will notice that something is wrong before this will occur. For example noisy valves or rattles.

my jeep runs on leaded ( super) but i cant remember what the head is made of..it's a 250 falcon.. 4.1 non X flow, ne 1 now wat the head is made of... ne way it runs on super... and we do a bit of travelin and not every servo sells super... so we carry this little bottle of " flash lube" ya mix i think it is 1 mill of the stuff to a litre... then in the can ur mixin it in u give it a shake and poor it in...... using unleaded fuel...... i dont think it owuld hurt to use it ..