"Leo Lichtman" wrote in news:9o4lk.283436 $ snipped-for-privacy@bgtnsc04-news.ops.worldnet.att.net:
I don't think that has had much, if anything to do with it. Lead actually acts as a lubricant. The advancement of materials, super precise CNC controlled machines that allow tighter tolerances and features that were not possible before, considerable strides in tooling, along with the massive advancement of Design tools such as CAD, FEA, sensors, data aquisition systems, etc. has had the most effect.
Actually he also invented interchangeable parts. See
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for details.
"It was Whitney's idea to make all the parts of his rifles so nearly identical that the machines parts could be interchangeable from one gun to another. "
Bruce-in-Bangkok (correct Address is bpaige125atgmaildotcom)
I think we came out a head on that one. The cure for no lead made for a more durable valve system.
Wes
-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller
On Sun, 03 Aug 2008 06:07:59 -0400, with neither quill nor qualm, Wes quickly quoth:
(Right you are, Bruce. Lead cushioned metal parts, I don't believe it caused any wear.)
Perhaps in one way. But the pollution from MTBE, lead's old replacement, is still gumming up the works badly. Do what you feel in your heart to be right - for you'll be criticized anyway. You'll be damned if you do, and damned if you don't. -- Eleanor Roosevelt
MTBE was not a replacement for lead. It was a fraudulent government mandated additive to oxygenate the fuel. It was highly toxic, and actually lowered fuel economy to the point where more fuel was burned and that wiped out the intended environmental benefit that the idiot do-gooders sought to solve in the first place.
Lead was used as an octane booster and was selected not for its incidental lubricity, but rather because it was the cheapest thing out there to boost the octane.
"Roger Shoaf" wrote: (MTBE) was highly toxic, and actually
^^^^^^^^^^^^^^^^^^^ It was also very prone to leak from the underground tanks. It invaded the water supply in many areas, and has been very hard to remove.
On Sun, 03 Aug 2008 12:05:17 -0400, with neither quill nor qualm, Wes quickly quoth:
At least the lead killed the in-tank bacteria and didn't pick up water to rust or freeze in your fuel lines/tanks.
-- Do what you feel in your heart to be right - for you'll be criticized anyway. You'll be damned if you do, and damned if you don't. -- Eleanor Roosevelt
On Sun, 3 Aug 2008 10:38:52 -0700, with neither quill nor qualm, "Roger Shoaf" quickly quoth:
It is both an octane booster and oxygenate according to the Wiki article.
Indeed, and now, with $4+/gallon fuel, it's really costing us. DAMN!
Right, the lubricity was incidental.
-- Do what you feel in your heart to be right - for you'll be criticized anyway. You'll be damned if you do, and damned if you don't. -- Eleanor Roosevelt
Since Wisconsin has required up to 10% alcohol in gas sold in the SE corner of the state, gas line antifreeze is no longer necessary. The alcohol combines with the water and keeps it from freezing. Maybe chemistry is different where you live.
Of course, the alcohol cuts gas mileage 10-20% and we pay extra for it...
Thanks for sharing your experience, William. If any designers out there know of significant changes in car engine block metallurgy over the last
50 years or so, and are able to share them, I would be very interested to hear.
I'm under the impression that cast iron blocks and/or cast iron cylinder liners were the norm in the 1950s, and that cast iron liners still are today, but I could be wrong. There have been some engines which use coated aluminium cylinders, but after the Nikasil and sulphur problems in the 1990s, I thought they were in decline.
Cast iron blocks have been around since day one of engine production. However the iron alloys used today are FAR superior. It allows thinner castings that have tighter grain patterns and through the use of newer alloys the wear and machining characteristics are such that the blocks made today last longer.
99% of the aluminum blocks use steel liners cast into the blocks. The rest use a type of chrome plating of the cylinder walls. Most of them are not built for long life though. Many are air cooled small engines. Things like lawn mowers and weed eaters. The industrial/heavy duty ones have iron or steel liners.
I can see that improved precision will result in a longer service life, provided that the surface finish is excellent. It's my understanding that for a hydrodynamic bearing in which the bearing's length, radius, rotational speed (for this, take the engine's idling speed) and lubricant viscosity are fixed, the maximum allowable load is inversely proportional to the radial clearance. So if the parts are very close-fitting, they will likely be able to carry a greater load than necessary when new, but the load they can carry without surface-to-surface contact will fall as the clearance increases due to wear.
Provided that the surfaces are not touching (except when starting and stopping), the wear rate will probably be at a minimum soon after the bearing surfaces are new, and after that it will slowly rise. If you are able to manufacture bearing surfaces with excellent precision and an excellent surface finish, you prolong the period in which the bearing is able to carry a greater load than is necessary, and prolong the period in which the rate of wear is low. Eventually, the bearing will no longer be able to support the load without the surfaces touching, and the wear rate will rise dramatically.
Babbitt metal can probably be seen as a bearing material which develops an excellent surface finish during the running-in period.
I imagine that multigrade oils reduce the wear rate at high temperatures and increase engine efficiency at low temperatures. I am not certain about the effect of oil additives. Do they work by adding a layer of slippery graphite to the bearing surfaces, in the way that cast iron does? Perhaps someone can explain?
A little over three percent or 13 cents a gallon for 4 dollar fuel. The complexity of using alcohol adds additional cost, iirc. Alky is mixed in close to point of final distribution.
I'm not sure that modern machine tools are more rigid, are they? Years ago they used to make some really heavy, solid machine tools.
have sensors
I'm not sure about this one. It might reduce wear due to less soot building up in the cylinder. I would be very interested to know if anyone has more information regarding this. But with electronic engine management, it also makes a vehicle way more complex to service.
There are also carburetted engines which are extremely durable. The Dennis Z Type lawnmower engine I mentioned, and the Ferguson TE20 tractor engine. Granted, these are slow-revving engines (less wear per unit time, and lower inertial forces), probably with fairly low operating pressures in the cylinders (leading to a lower transverse force per unit area). It might be that these two factors are more significant than the method of fuel delivery.
Electronic engine management has its advantages and disadvantages. On the one hand, it gives you better cold starting, fuel economy, emissions and probably better short term reliability. But if you are interested in old vehicles, or you're just cheap and want to run your old car forever, it makes home servicing a lot harder.
They could make things easier by using fewer different microprocessors (that is, standardising more), publishing more documentation and perhaps having a chip which you can plug into the microprocessor unit carrying the necessary code for a particular engine. Like a Game Boy cartridge. I can't see it happening right now, though.
That is without a doubt good advice for any machine.
Not sure about this one either. I remember starting a thread here a year or two ago about whether or not engines which burnt oil lasted longer. The consensus seemed to be that they did not:
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Incidentally, someone mentioned in that thread that the part of the piston above the rings is typically of a smaller diameter. Anyone know if that's true?
This is very interesting. I was thinking of buying some lead replacement additive for my old machines, but now I might not. Actually, I discovered that you can still buy tetra-ethyl lead in England. Freedom of choice is great :-):
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Then I read Leo's post, and also found this, which supports Leo's idea that lead "In 1985 an EPA report concluded that reduced lead levels reduced piston-ring and cylinder-bore wear, preventing engine failure and improving fuel economy. Estimated maintenance savings exceeded the maintenance costs associated with recession of exhaust valves, which is caused by the use of unleaded gasoline."
Now I'm not sure that the EPA are impartial, but I'd really like to get hold of a copy of that 1985 study. Anyone know where I might find one?
So I'm a bit unsure whether to buy a lead replacement additive for my old machines. Perhaps there's one which is better than tetra-ethyl lead from a wear prevention point of view? After all, the mechanisms of bore wear and valve seat wear are different. Maybe there's an additive which protects the valves, but doesn't wear the bore? Anyone know?
What do other people use for their vintage machines?
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