Leaded Gas

[LDunville]

I hope this is not a redundant topic, which I imagine is probably is, but how do other cope with old cars requirement for leaded gas. Will my 68 911S have a problem with non-leaded premium? Should I be using an additive???

Thanks for the assistance.

[sithot]

Not much you can do other than to have hardened seats installed when the top end (or entire engine) is rebuilt.

http://www.vw-resource.com/additives.html#lead

"In the United States lead additives have been completely banned, and compounds such as Methyl Tertiary Butyl Ether (MTBE) are added to raise octane rating and promote more-thorough combustion."

MTBE is gone. NOW we have an abomination called E85. Ethanol is actually worse than MTBE. Your government at work. FWIW; other countries WITHOUT Ethanol subsidies still use MTBE. Again, your government at work.


Read the "mixing" thread if you want more information on fuels out here.

Good luck!

Tom

[docrodg]

The only downside to the removal of lead these days is in engines that have "soft" valve seats as the designers counted on lead lubricating and cushioning these seats. Engines that have a soft seat will experience seat recession into the cylinder head and accelerated valve seat wear. This problem was studied extensively by many and there are good research papers out there on the topic. The cure was to change to a harder valve seat material with larger bore in the head for the seat so there was more metal to support the seat if the head material was soft. THe engines that were known most for this problem were on american cars where they used cast iron heads and softer iron seats rather than steel or other materials.

Porsche used harder valve seats and head material than the engines that had problems.

An interesting article from Bruce Anderson can be found here: http://www.911handbook.com/articles/...adedfuels.html

While lead made a great octane booster it is bad for engines as it fouled other parts up and it is very bad for animals (like us) and the environment in general. IMHO most of the arguments against bans on some additives are based more on the cost increase in the fuel or due to a decided hatred of regulation by the government or viewpoint that regulation is taken too far. I just try to remember that we had no environmental regulation in this country until we caught a river on fire.

[Flieger]

Porsche valve seats are already hard enough. No issues with unleaded.

[super9064]

Porsche valve seats are already hard enough. No issues with unleaded.

Flieger is right, Porsches have had hardened valve seats since the 356. Can you still get race gas with lead?

[Tom F.]

Flieger is right, Porsches have had hardened valve seats since the 356. Can you still get race gas with lead?

I think that some early 356s had bronze seats, but that was long ago.

[sithot]

Closer to home for me.

http://www.worldwideracingfuels.com/default.aspx

260GT or the 107 leaded. All of my bikes have hardened seats in them (now) and it's not an issue BUT I will not leave Ethanol in anything that is going to sit for an extended period of time.

Tom

[sithot]

Stop lying

open up your freezer.

raj

Shite! Busted.

I take that back. I will leave anything with Ethanol in it in the freezer.

Tom

[Neil '67 911S]

MTBE is gone. NOW we have an abomination called E85. Ethanol is actually worse than MTBE. Your government at work. FWIW; other countries WITHOUT Ethanol subsidies still use MTBE. Again, your government at work.

Tom

MTBE was banned because it has caused the pollution of groundwater, which is widely used by people for drinking water. E85 poses no similar threat to people.

[sithot]

I never said it was good but ethanol is no better and costs more to produce and you and I pay for it. It's called the Corn Lobby in D.C..

Oh yes; a couple of things to consider before jumping on the corn-hole bandwagon:

It is just plain stupid to use a food source to make fuel.

http://www.forbes.com/sites/christop...werent-illegal
http://www.bizjournals.com/twincitie...astewater.html
http://www.jsonline.com/business/eth...146431115.html
http://www.winnipegfreepress.com/art...148178575.html
http://www.cbsnews.com/2100-205_162-508006.html