I've been using Torco Accelerator. Seems like the best bang for the buck, and it seems like it actually works. I hope it's not just wishful thinking. 11.25/1 c/r, iron headed SBC and no signs of detonation with 38* total advance.
Gunk makes one...part number m5012 available at any auto parts store. I use it all my older small engines , on older car engines I had hardened exhaust seats installed
From what I learned from my boss when I was working in a race shop in my early twenties lead was just a lubricant just like sulfur is to diesel fuel Does nothing for octane boosting From his research adding Marvil Mystery Oil will preform same function it produces a ash when burned that lubricants the valves As a side note the owners manual for my father’s ‘63 Mercedes 190 diesel said you could use kerosene if you added so much engine oil to it which we had to do because diesel fuel was not that plentiful back then We had a diesel tank at the house You knew you were at the race track when you smelled the cam 2 burning
Just get an Aviation Fuel Card and use AVGas as the lead substitute. AVGas can sometimes end up cheaper because there is no road taxes added.
No, I just run whatever they have at the pump wherever I am. I have one that likes 91 or 93 when I'm racing, otherwise 87 (or 85 or 86 if I'm in the Rocky Mountains).
Well, that was bad information. Yes, the lead is a lubricant of sorts, it plate's out and acts as a sacrificial surface. on the valveseat and valve stem But he was completely wrong about it not decreasing detonation resistance. Tetraethyl Lead is one of the most effective antiknock agents and this was the reason it was introduced into gasoline....not the lube factor. In fact, if it wasn't so poisonous to living things it would still be in wide use.
I use some every once in a while. About 5 years ago, I bought about 12 gallons of actual tetra ethyl lead. The date on the jugs is 1988. Not sure what the shelf life is, though. It was very cheap, so I'm not out much if it isn't any good.
Back in the 90's, Australia changed to lead-free fuel. There was a big rush on lead additives. They were sold on the premise that lead is an upper cylinder head lubricant, and that without some form of additive you would suffer from valve seat recession in older cars. If you fitted hardened valve seats, then no longer any need for the additive. I'm not so convinced. I've done a stack of daily driver miles in the sedan version of my avatar over 15 years with no lead additive, and have not seen any valve seat recession. I haven't seen anyone in Australia yet who has suffered from it either. Suspect some of the claims for the lead additives are closer to snake oil. YRMV. Cheers, Harv
here's your first confirmation then, its a thing, it happens. When I was doing engines for a living it was quite apparent. Granny drivers not so much. Its not apparent now as there is nothing around doing big hard miles without hardened seats or inserts.
I have added a bit of diesel (about 1ml/litre of gas) for a few cars which didn't have hardened seats. I read a report on the "valve saver" gear, it was mostly diesel.
Some engines came with hardened exhaust seats. I hand cut the seat on a 218 a bit back, you could sure tell the difference between the intake and exhaust. I wonder if OHV older engines were the same? Oldest set of heads I have left and accessible are mid 70’s Chevy, so probably have them (hard exhaust seats) from birth.
Of course. You need a solvent to mix the active ingredient in. Also, average Joe may not be too good at mixing chemicals at ratios like 0.00001 : 1 with enough accuracy (and may often think more is better), so it makes sense to dillute consumer products so you have to pour a larger amount of them in the tank.
Oops my apologies you are correct My fingers were typing faster then my brain last night To much alcohol in my gas Aw man didn’t mean to bring that up…
On my first old car I did religiously as I was told and thought catastrophic failure would ensue. then I ran out one day far from home and the city and had no choice but to drive home . magically nothing catastrophic happened. Someone posted , unless your beating on your ride all day , everyday I don’t think it matters one way or another .
Yes. The Chevy shop manuals from the early 70s mention that they started to induction harden the exhaust seats, for use with the new unleaded fuel. I've had the seats go out in exactly one Chevy with unhardened seats....a 283 in a 58 wagon.
Bought this RV with 70K on the clock and limped it home, hard working miles for the little SBF. The exhaust seats were so far in the heads the lifters were bottomed. Put on some '80s junkyard heads and put another 50K on it. Main factors for seat recession in old heads? Heat certainly, valve spring pressure, miles, cast iron makeup, rpms?
All my old cars have had the heads rebuilt with hardened seats and SS valves so they don't need leaded fuel.
Most flathead ford v8s have hard seats from the factory. I think it mostly depends on the quality of the casting for soft seats. That, and valve spring pressure. I have soft seats in a few cars. Albeit they dont see daily driver milage. A friend was daily driving his c10 with a lumpy cam and some old 461 heads. One day he lost a cylinder. We pulled the heads and one valve had sank a seat. By that time, every guide was so worn you could wiggle the valve stem 1/16 back and forth. Pretty sure they had ALL of the miles on em. My other buddy jj rode his old 76 ironhead chop on a 4 day ride. After the second day, we had to back off the exhaust valves. That became the morning ritual for the next couple days. When we got home, the valve had worked its way 1/4 in into the head. It also had big cams and heavy springs, and the benifit of being a quality AMF casting.
If you do a little research into the effects of lead on the environment and on people exposed to it you won’t worry about it being gone from our fuel. Not that I’m all green and hugging every tree in the neighborhood but lead was phased out of fuel for a valid reason. We don’t need it.
I’m a real scientifical person. The engine needs gas so I use it. I’ve put far more miles on older engines withou lead than with. Never an issue. I’ve only heard of issues in some heavier vehicles. That being said, the last set of head I had built got hardened seats. Wasn’t very expensive. My flow chart for using unleaded gas: Put unleaded gas in ride. Drive the crap out of it. If nothing happens -cool If something happens-fix it
As a side note I work on a lot of propane powered units at work the 4.3 vortec engine is a “standard” engine in a ton of forklifts Yale Hyster HELI Hengcha Clark Toyota And many others. propane runs lean and hot and does not offer the lubrication gasoline does. About 10 years ago toyota got a ton of 4.3 that would eat valve seats . Only Toyota . They are the #1 forklift manufacturer in the world ( we’ll them and all the companies they own in total , semantics , but anyways) was this industry sabotage ? Or just a “ bad batch”
Hey Mike. If the seats are not hardened Ive heard you need a lead additive. Thanks guys for all the info, it helps
You might need one, you might not. If it's an engine that's working hard all the time, it might have problems, or it might not. If it's loafing most of the time, you'll probably be fine without.
The Jalopy Journal
