leaded

[Peter Connan]

Morning Gentlemen


I need the help of the clever guys, my apologies if this has been covered before. For some time now I have been worried about this, and it finally happened last night:
How will my old-tech 4.2 petrol handle unleaded fuel if LRP becomes unavailable.

I remember several years ago this was a hot topic in the British magazines that cater for older cars, and if I remember correctly there were two possible problems arising from using modern unleaded fuel in old engines:
1) Valve Seat Recession, which is the valve seats getting bashed into submission by the valves closing because they are operating at higher temperatures, which in turn is due to the shielding/cooling effect of the lead not being there anymore.
2) Some of the rubber/sealing elements perishing more quickly.

Now in terms of the first point, this was only seen as a problem on cast-iron cylinder heads with integral seats, but our engines already have aluminium heads with pressed-in seats, however when I asked Nissan they said I should avoid unleaded fuel, but they could not or would not tell me what was going to go wrong.

Does anybody on this forum have any knowledge of what will go wrong in the Y60 engines (and older) if they are run extensively on unleaded?

Thanks
Peter

[Jules]

Peter I will follow this thread with great interest

Shalom
Jules

[Herrie]

As far as I know, all Nissans can use both LRP and Unleaded with no problem - if you do not have a "cat"in the exhaust otherwise LRP can be a problem.

[David]

I agree with Herry, No worries - even my old 1981 2.8 Safari could use both although they stated that the timing should be slightly retarded (I think that was because the octane levels went from 95 to 93 @ the coast). I never bothered and it ran fine.

[Peter Connan]

Thanks Gentlemen
I can better now.

Peter