Etusivu Foorumit Päävalikko Tekniikka Mikä on mikäkin suutin Vastaa aiheeseen: Mikä on mikäkin suutin

#279453

Lyijynkorvikkeesta ja 2CV:n tarvetta siitä on ulkomailla keskusteltu jonkin verran. Mm sivustolla kerrotaan näin:
“Leaded or Unleaded Gas
The other big question is if the 2CV can run on unleaded gas. When leaded gas was banned in Europe many years ago, a big discussion started. Especially in the UK 2CV owners were involved in heated discussions weather or not to use unleaded gas. Citroën went the easy way. They simply said that all their cars built after a certain year (Which I don’t remember) can be run on unleaded gas.
To answer this question, we have to look into the function of lead. In the old days lead was added for two reasons. It boosted the octane level – which of course is accomplished today by other additives, and as a lubricant/buffer for the valves. Whenever a valve closes, it smashes back onto the valve seat. This requires a tempered valve and a tempered valve seat to make them last. In the old days engine blocks and cylinder heads were made from steel. The valve seat was just milled into the head, so the valve seat couldn’t be tempered. A buffer was needed to dampen the impact of the valve onto its seat. The lead additive performed this function. Without the lead the valve seat would suffer. That’s why old style engines need a lead additive.
The 2CV however was always produced with an aluminum engine block and cylinder head. Aluminum could never withstand the impact of a tempered steel valve, that’s why Citroën always integrated tempered steel rings as valve seats into the cylinder head. Now both sides are tempered, so the lead became obsolete.”

Itse ajan 98 ilman korviketta, ja kahvinikin juon aitona 😉 ilman maitoa.