Lead additives?

I'm sure this opening up an old subject but does anyone add a lead substitute to your old cars? How often, every tank? I know you can get the valve seats changed, my GT6 engine had that done when it was rebuilt, but I have a few older cars and a motorhome that can burn leaded fuel. Does anyone have any evidence that unleaded fuel causes harm?

thanks mike

I've been using the Sunoco GT 100 unleaded race gas for about 5 years in my race Spridget. The head's been off several times and I see no real evidence of excess wear such as seat recession. The car runs about 25 track hours per year. My car has 10.75:1 compression and runs about 30 degrees of total timing advance.

I know a lot of folks use these additives as octane boosters. But if you look at the amounts of lead (and "lead substitutes") contained in the additives, you will see that you'll really need about one full container per gallon to do anything useful in terms of octane.

I dump my left over racing fuel, 110 Leaded in my 77 gray market, no cat, Mercedes 450 SLC to get a little more zip and some lead on the valve seats. I might do it with the older spitfires too but the motorhome, 454 engine, 6 MPG will just have to make due with pump gas.

thanks

mike

Older article

Cool mercedes, I'd be worried about plugging up the fuel injection with the additives. Mine is a 280slc. I don't think the race gas would do anything special for the mercedes, I've tried about every snake oil and the car consistantly runs the same.

Is the mercedes a manual?

I wish it was, not a big fan of automatics but it's still a fun car to drive.

We all wish they were manuals, but that wasn't in the 70s mercedes buyer's dna. Nice car and thanks for some photos. I kind of wonder what the manuals feel like. Cool photo and I love the slc's.

I hate to say this the the manual gearbox is a lot like the one on a 240d. The V8 cars are way better suited to the automatic. I was underwhelmed by the few I have driven with the manual.