Gunk lead substitute, yes or no?

Educate me about lead substitute, please. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>
As we all know that we are using unlead fuel due to emission reason. According to what I read, the lead substitute prevents valve seat damage in engine designed for leaded gasoline. Prolongs the useful life of older engines without updated valve seats. <o></o>
I went to a NAPA autoshop and asked for lead additives. The guy sold me a bottle of Gunk lead substitute. What do you guys think about it?<o></o>

No one I know uses it. There is no need for it.

+1. The Japs and Euro's have been using unleaded since the 70's, and so their vehicles have been designed for it.

If you're talking good old-fashioned cast iron dinosaur V8s that we all know and love, in a mild state of tune the standard heads will mostly do 20K - 30K miles before the valves need doing again anyway due to recession. Not many people run 70's Chev/Dodge/Ford hotrods day-to-day anymore.

I had a similar discussion about valve seats with a Navy fuels officer. Old school Warrant, so I assume he knew what he was talking about. He told me to just put one tablespoon of kerosene into each tankful of gas. That was for a car, so maybe one teaspoon for a bike?

All that'll do is make your exhaust smell funny. There is no lead in turpentine.

Please point out to me where in my post I actually mention the word "lead."

I've been using a lead sub in my old vehicles for years now. But...I'm running out of the stock I had before so am in the market for some new stuff.

One of the other things I do is also mix in 2 stroke oil at about 100;1 for all these old bikes. Keeps carbs sliding smoothly, keeps rust out of tanks, etc. I was wondering if a mild mix of 2 stroke oil like that would do just as good at protecting valves as lead would.

I use a product I get from Wal-Mart called CD2. It goes a really long way. Put some in every couple of tanks full. Cant really say whether it makes a difference or not. I have friends that add some AvGas in the same fashion. Hard to tell whether it makes a difference without doing some real complicated tests on bikes riding in the same conditions using the same gas over a really long period. I am probably doing it as much for my own well being as the bikes.

My initial question was for BMW airheads, but I guess nobody here really put lead in the gas tank for the airheads anymore, right?


On the other hand, that would be interested in to know what you guys put in the gas tank to make your old engine happy.
personally, I will down in a bottle of whatever on sale brand name fuel inject cleaner into my fuel injected vehicles. I can NOT tell any difference, but I guess it's more like a piece of mind. Once awhile I will also put some stabil in the tank.

CD2 is what I had used as well but am running out and Wally World does not carry it down here.

I put a blend of olive oil, Inconel dust, invert sugar, Worcestershire sauce, and Starbucks "Christmas Blend" in my gasoline.


I can tell it's winter time.

Can you suggest what's the best oil to use???




FIDO

*snicker*

Anyone know how a propane conversion on a mid sixties British bike would effect the valves/seats?

After consulting with Hank I've found that:

It'll push the seats right thru those limey heads you dumbass.

And then ya gotta tote around a pressure vessel fuel tank......you no better'n that don't cha 'Tuna???

If you're worried about your '80, you probably don't need to. I'm pretty sure them German engineers installed hardened valve seats by then. Heck, Japanese engineers had been since 1972 that I know of.

As far as stuff I put in my old bikes, and my new(er) bikes, and my old cars, and my new car (when I briefly owned one).....SEAFOAM! I use it for both gas and oil.

I've run BMW's going back to 1952 pretty hard and never worried about the valves. Keeping them synched is another matter.

In my Main bike, I run a dollop of marvel Mystery Oil to help lube the top end.
In bikes I rarely ride, I use 3 dollops of 80% Sta-Bil and 20% MMO. Seems to work just fine for me. As instructed many years ago, and I've been doing this for 40 years come January.

Every decent mechanic I know says lead substitute is snake oil.

I just capture slithery snakes, whip em up in the wife's blender and pour into gas tank. Works just as well as anything you can buy and is a whole lot more fun to catch. Just watch out for the ones that make rattle noises, as they tend to up the octane rating too much.

OP was asking for a lead substitute. Maybe your reply was the right answer to the wrong thread?...

And I wasn't entirely correct in my answer: in addition to making your exhaust have a faint bouquet of diesel, it'll also drop the fuel's octane a bit too.

As far as helping the valve seats goes...