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Discussion Starter #1
A conscerne came up that LRP will start disappearing all together soon. There are some additives one can add to unleaded to make it OK to run older cars.
The question is: how carefull should one be to over adding additives? Or is a bottle per fill-up OK?
Follow-up question is if those additives OK to run with octane boosters?
 

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A conscerne came up that LRP will start disappearing all together soon.
The LRP problem had me wondering as well, as I do not intend to sell the old Spider ever. But I do not think the old Alfa engines are a problem with unleaded fuel. They have aluminium heads with reasonable quality valve seats. I do not use the Spider that often but burned many tanks of unleaded so far.

Lets look at the theory. In the Voortrekker days, iron was welded by putting the two pieces on top of each other, and after heating it to red hot, beating it with a hammer till the two pieces became one. Now the same process of heating and beating happens inside your engine. The outlet valve and seat have red hot gas flowing over it and the valve spring is beating it many times per minute.

The lead in the fuel left a layer on the valve and seat so the they don't 'stick' together and start the welding process. Without the lead this do happen, if the valves and seats are made from materials that contain less chrome/nickel. Minute pieces of the valve seat will be ripped out of the seat and stick to the valve in a process sometimes called scuffing.

If you have an old car with cast iron heads, like the old GM, Ford fours, sixes and v8s you have a problem. In those engine the cast iron the heads are made of, are just cut to form the valve seat. On these engines it normally take about one tank of unleaded to damage the engine enough for it to start misfiring. The answer is to strip the heads of the engine, take it to a reputable machinist to fit modern valve seats in the heads.

Gertjie, I can not answer the additive question as I have no experience with it.
 

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Never ever ever ever use crappy LRP unless you drive a old Ford with a kent or a X tappet R 6.
Enough said.
 

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I've used unleaded in my 159 for years and nothing ever broke. In the US they've been running on unleaded and catalytic converters since the 70's and their engines don't seem to suffer from premature wear...:thumbs:

I remember my father's Alfetta and Giulietta owners manuals always had a section on catalytic converters and parking on long grass...
 

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Discussion Starter #5
Thanks Guys for the feedback -

There are lead replacement additives you could add to unleaded petrol - but if you can run Unleaded as is - then the additive question becomes mute.

The question was raised by some old toppies - I'll get my story as straight as possible to try and convince them to - leave the bottle :cheese:
 
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