Unleaded Fuel

Is it right to asume that a 1.8 litre aircooled engine from the States will run on unleaded fuel in the UK?

Reply to
Bill Payer
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We've had only unleaded over here for a while now too. Darnit.

Reply to
Michael Cecil

That would be "Yes".

Reply to
COX

Unless it's GEX, then it will not run on any fuel.

Reply to
none

A bit back-asswards there, aren't ya.

**************************** Andy 'Dubless for the time being ****************************
Reply to
Jeckler

The official VW position is that after x number of years running on 4 star, the relevant parts will have hardened enough to run on unleaded without probs...

Reply to
Rob Lynn

This is referring to the 'Lead Memory Effect' which is still a controversial subject in the industry. VW's 'testing' appears to have been very limited.

Reply to
Peter

This is different than lead memory, where lead deposits stay on the valves and seats for a while after switching to unleaded. What VW was referring too is that the exhaust valve and seat are work-hardened after many years of hammering, so they will run without any problems on unleaded fuel.

Switching to unleaded fuel is supposed to increase a bit head temps. So the ACVW engine will not tolerate to be out of proper tune as much as when running on leaded fuel. When switching to unleaded you should therefore check regularly the valve clearances, the ignition timing and the carb adjustments. You may have to retard the ignition timing a bit, if you hear the engine knocking.

If you don't neglect to keep the engine in perfect tune, it will run just as fine on unleaded fuel as with leaded.

Bill, '67 bug.

controversial

Reply to
Bill Spiliotopoulos

I was not aware of a VW statement on 'work-hardened' valve seats etc. Can you point me to the information on this?

Reply to
Peter

I do not have any official VW documents about running unleaded on aircooled engines, though I've seen this information show up here sometime in the past. Anyway, all T1s manufactured from 1968 and after, had hardened valve seats from the factory and can run on unleaded without valve seat recession problems. They just were not tuned for unleaded from the factory, so you have to tune them yourself (retard timing as necessary or lower CR a bit).

Bill, '67 bug.

Reply to
Bill Spiliotopoulos

As I understand it, the only change made for 1968 was the actual valves themselves. The seats and guides were fine. However the valves installed for the US market were not the same as the ones fitted for the Europeans, although by the mid 70's the 'good' valves were all you could get as original replacement parts. T the time, when the lead content in fuel was reduced in the US, there was no need for timing adjustments as it still met the octane requirement of the engine. However, since these octane numbers have dropped below the VW minimum requirement, it has become necessary to either adjust timing, or preferably, reduce the compression ratio.

VW (in the UK) issued a statement as regards the 'lead memory', declaring the air-cooled models now suitable for use with unleaded, without modification. From their statement, it seemed based on their desire to not want to be bothered by the subject any more, rather than a need to inform. With the passage of time, it becomes more unclear since so many cars are not fitted with factory original parts and, the general spread of mis-information further confuses.

Reply to
Peter

When they stopped selling leaded fuel here in Sweden all gas stations had a list of which cars that needed additives. According to that list all VWs from '78 and on are OK without lead, but VWs up to '77 needed additives. When I sent an email to VW and asked them if my aircooled VW really needed the lead they just answered that it is up to me if I wanted to run the car on unleaded or not but they recommended me to use additives. I got the impression that they didn't want people to blame the unleaded fuel when they got problems with their old engines.

/Sven

Peter wrote:

Reply to
Sven Agardh

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