T.E.L. to help protect valves from regressing.

[rustybronco]

http://bmwmotorcycletech.info/valves.htm

About 3 or 4 ounces of aviation leaded gasoline, in the commonly available grade called 100LL (100 octane Low Lead) is needed per gallon of UNleaded car gas, for good protection on the 1979 and earlier airheads. On a practical basis, less than this amount seems OK, and many have had good results by simply adding a cupful (a cup is 8 ounces officially, but in practice is 5-8 ounces) every few tank fillups. NOTE that this usage for road vehicles is illegal in the U.S. Still, many who have lawnmowers, etc., with old type seats, add a small amount of aviation fuel to their tanks.


For those wishing more exacting information, aviation fuels containing either 4 or 8 grams of tetraethyl lead per gallon are, or were, common. Leaded fuel for airplanes was typically available in 87 octane, and low and high leaded 100 octane. Today, only 100LL is likely to be found at airports. It is commonly accepted that approximately 0.1 gram (some say up to 0.3 for high protection) of tetraethyl lead per gallon is enough to provide reasonable valve seat protection. This is FAR LESS than the amount required to boost octane any appreciable amount. Using the 4 gm/gal specification type of aviation gas (100 LL), only .025 gallon of aviation gas is needed per gallon of unleaded car gas. A gallon is 128 ounces (U.S. measure). Thus, only 3-1/4th ounces of aviation gas per gallon of unleaded car gas is required for acceptable protection. Frankly, less is needed, as aviation piston engines normally work very much harder than our airheads.

 

[tkent02]

I melted my spark plugs down to little nubs doing that a long time ago.

 

[rustybronco]

Adding 100LL in small amounts to unleaded fuel caused your spark plugs to wear at an advanced rate?

That doesn't make sense.

 

[Dogma]

Adjusting valves isn't that big of a hassle is it? Maybe on the Beemer?

 

[tatu]

Adjusting valves isn't that big of a hassle is it? Maybe on the Beemer?

It is a problem every couple of hundred miles having to do tappets because of valves tightening up, I had that on my T140.
I used an additive still was a problem....

http://www.ebay.co.uk/itm/Castrol-V...additive-/380170558179?_trksid=p2054897.l4275

The only real way to deal with it is have the proper hard new seats installed, then fixed forever.

 

[tkent02]

Adding 100LL in small amounts to unleaded fuel caused your spark plugs to wear at an advanced rate?

That doesn't make sense.

No they didn't wear, they melted in about an hour or two. Avgas is different, it is a naptha based fuel, which burns a lot hotter. I tried to save a few bucks by pouring the fuel from the coffee cans used for airplanes to drip their overflow into, so I'd pour a little into the bike. Maybe a cup or two. Maybe more. Certainly much less than a gallon. Couple hours later the bike is missing badly, pulled a spark plug and it was just a little nub. No electrodes left at all. All four were like that. New plugs, new gas, had no further problems for years and years. This on a nearly new 1977 GS 550, back in 1978.

 

[tkent02]

Adjusting valves isn't that big of a hassle is it? Maybe on the Beemer?

Super easy to adjust valves on Beemers.

 

[rustybronco]

http://www.unep.org/transport/pcfv/pdf/VSR-FinalDraft.pdf

Especially read pages 11 and 12.

 

[tkent02]

http://www.unep.org/transport/pcfv/pdf/VSR-FinalDraft.pdf

Especially read pages 11 and 12.

They pretty much say don't worry about it.

Kind of like we've been doing.

 

[gearhead13]

I used to run avgas in my hod rod car, sometimes almost a full tank. Never had a problem. I was young and thought that more octane meant more horsepower. It had almost 11-1 compression.

 

[tkent02]

Yeah it was fine in my Barracuda, too but not in the bike. I don't know why.

 

[chuck hahn]

Ahhh Maybe at a ratio of a cup or more, as you described it was too hot???

They did say about 4 to 8 ounces ( or something like that ) per tank full.

 

[chuck hahn]

some additives.....

http://www.ebay.com/sch/6000/i.html...mpt=Motors_Car_Truck_Parts_Accessories&_rdc=2

 

[rustybronco]

They pretty much say don't worry about it.

Kind of like we've been doing.

Looks like that's the case for the bikes coming out of Japan. Unfortunately there are other machines made pre '74 and those bikes made elsewhere such as Europe.

 

[tkent02]

There are lead substitutes that won't burn up spark plugs.

 

[rustybronco]

Yes, both potassium and sodium based.

From what I've read, under light to moderate usage, the lead replacements appear to perform adequately 'in most cases'. High temp, high load not so much.

Neither is a drop in replacement for T.E.L.

Going to get me a fiver of 100LL, mix it with 87UL and dole it out in the Beemer and my W-6.

 

[chuck hahn]

Would any of the lead subs be of any value in the GS engines Dale?????

 

[rustybronco]

In my opinion and what I can tell so far, there is no need to use T.E.L. or a T.E.L. substitute in any of our engines.

What I do think, it's a good idea to run valve clearances on the larger end of the scale. That way more of the heat gets transferred from valve to seat than it is to worry about using lead or a lead substitute- in these engines.

Not an expert on the matter. Just was worried about valve seat regression.