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#41
 
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Re: Reg versus Premium Fuel experiament in 09 PT Cruiser -
11-06-2009
, 06:28 AM
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...And yes, everybody knew lead was toxic, but I don't think anyone had any notion just how toxic it was. Remember only 20 years before, lead acetate was a common ingredient in cakes and candies... |
ingredients in many brushes in the d.c. motors and alternators on our
cars. I was amazed to learn that when I worked as an
engineer/engineering manager in a brush manufacturing company supplying
60% of the brushes to the U.S. auto industry.
Think about it - lead in the brushes - brushes that wear and create dust
that gets blown about into the air. Who'd a thunk that they would allow
that - but it's a fact and you never hear anything about it. Whyizthat?
--
Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')
#42
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...No you are confused. The lead didn't cause any unusual wear to the valve seats... |
--
Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')
#43
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No you are confused. The lead didn't cause any unusual wear to the valve seats. That was about the only internal component in the engine that had the same wear as unleaded. The study showed the rest of the engine does see accelerated wear when run on leaded fuel. The tests were done on modern engine comparing modern fuel to fuel of the same octane formulated with TEL. The study may have been funded by the UN. Lead is still used in some third world countries and there is some efforts to encourage them to stop. |
fact cause unusual wear to the valve seats, so I am curious where the
added engine lifetime came from here. Cite, please?
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
#44
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jim wrote: ...The current extended spark plug change intervals are really almost entirely due to the removal of lead from gasoline. Typically spark plugs electrodes and insulators erode 4 times as fast when using leaded gasoline. I wasn't aware of the faster electrode erosion with lead, but I do know that quite often spark plug life was limited because of the lead being vapor deposited onto the insulator that bridges the electrodes such that eventually the surface of the insulator became conductive and would short out the voltage before ionization/spark could occur. That's what I saw more than anything forcing spark plug replacement when I was a much younger DIY'er. |
Again this is an issue of efficient combustion which tended to be hit or
miss back in the 60's. So there was a whole science to how your engine
was running (or how it could be improved) depending on how the spark
plugs deteriorated.
-jim
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-- Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x') |
#45
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On Thu, 5 Nov 2009 19:54:01 +0000 (UTC), Brent tetraethylleadREMOVETHIS (AT) yahoo (DOT) com> wrote: On 2009-11-05, Matthew Russotto <russotto (AT) grace (DOT) speakeasy.net> wrote: In article <-NydnQPDm9rTim7XnZ2dnUVZ_sGdnZ2d (AT) texas (DOT) net>, Steve <no (AT) spam (DOT) thanks> wrote: Also left out of the discussion is the fact the the VERY BEST motor oil you could buy in the late 60's wouldn't qualify as chainsaw bar oil today. Lubricants have come WAY further than engine design- at least in terms of bearings, rings, and other "hard" parts. Fuel managment systems have come as far as the oils or even further. If you could find a "pickled" (preserved, never run) factory engine from 1965 and put it into use with today's synthetic oils It would fail in short order without good old tetraethyl lead in the fuel; no hardened valve seats in an engine from that era. I'm not so sure about that. it seems that such wear isn't as bad as was once believed. What was found was that if you ran leaded fuel for a few thousand miles it built up a coating that could provide protection for a long time after that even if you burned unleaded. |
engine that protective lead coating penetrates even deeper than the
metal removal from grinding the valves. The protection of a lead coating
is Voodoo.
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But if you took a new 66 engine that had never been run and started it off on unleaded it would burn the valves relatively quickly. That's why when leaded gas was phased out there wasn't the problem people thought there would be - all the already in service cars had been run on leaded for a long time and the new ones had hardened valve seats. |
were using leaded fuel. In fact back then it happened frequently. One of
the reasons was the breaker point ignition always meant that the engine
spent a considerable amount of its life with late timing due to breaker
points wearing down. Subject a modern engine to the same late timing and
it will burn valves also. And detonation is hard on the intake valves
so advancing the timing in anticipation of the expected wear would also
cause problems. The simple fact is that in order to make a 60's engine
last as long as a modern engine you need to do a tune-up with the same
frequency as you change oil.
Where is the evidence for these engines that burn or recess valves
without leaded fuel? If you install a properly working electronic
ignition in an old style engine you are probably doing more to protect
the valves from burning than hardened valve seats will.
This whole business of lead protecting valves was a made up lie in the
first place. It is a fairy tale designed to scare the public into
continuing to poison itself. What protects valves is efficient
combustion. The octane increase from lead made efficient combustion
possible. Raising octane by other means can accomplish the same thing.
There is no protective coating from lead. In fact the byproducts of
burning lead have been shown to accelerate engine wear.
-jim
#46
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jim wrote: Ashton Crusher wrote: On Mon, 02 Nov 2009 10:25:45 -0500, elmer <e@f.udd> wrote: I don't understand you claims of "junk" engines. Today's engines are far better in pretty much every way then everything that came before them including durability. That's a general statement, there will always be a few bad designs. Up until the mid/late sixties, engines were so weak that it was common for them to need valve jobs before 100K and for many of them they needed both rings and valves before that point. There used to be a thriving industry doing ring and valve jobs there was such a demand for it. But that has nothing to with the engine itself. To claim that burning rings and valves is evidence of a "weak" engine is silly. Also left out of the discussion is the fact the the VERY BEST motor oil you could buy in the late 60's wouldn't qualify as chainsaw bar oil today. Lubricants have come WAY further than engine design- at least in terms of bearings, rings, and other "hard" parts. Fuel managment systems have come as far as the oils or even further. If you could find a "pickled" (preserved, never run) factory engine from 1965 and put it into use with today's synthetic oils |
the cam would likely fail in very short time due to the reduction of
ZDDP additives in todays oils.
I ran down one lobe on a 351C in Italy (I'm from Sweden) in 2004 while
using Mobil 1 5W-50 oil, and a lot of 351C owners have had flat tappet
cams fail in very short time, some even during cam break in, using
modern oils.
I'm now running a hydraulic roller cam and roller rockers, and it has
at least survived a trip to France.
Thomas
#47
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In article <-NydnQPDm9rTim7XnZ2dnUVZ_sGdnZ2d (AT) texas (DOT) net>, Steve <no (AT) spam (DOT) thanks> wrote: Also left out of the discussion is the fact the the VERY BEST motor oil you could buy in the late 60's wouldn't qualify as chainsaw bar oil today. Lubricants have come WAY further than engine design- at least in terms of bearings, rings, and other "hard" parts. Fuel managment systems have come as far as the oils or even further. If you could find a "pickled" (preserved, never run) factory engine from 1965 and put it into use with today's synthetic oils It would fail in short order without good old tetraethyl lead in the fuel; no hardened valve seats in an engine from that era. |
Unfortunately I wasn't one of them- lost a valve and had to put in
hardened seats. Still made it to over 200k miles on that engine though.
#48
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What was found was that if you ran leaded fuel for a few thousand miles it built up a coating that could provide protection for a long time after that even if you burned unleaded. But if you took a new 66 engine that had never been run and started it off on unleaded it would burn the valves relatively quickly. That's why when leaded gas was phased out there wasn't the problem people thought there would be - all the already in service cars had been run on leaded for a long time and the new ones had hardened valve seats. |
number of years before the actual requirement. Chrysler started putting
induction hardened seats in some engines around 1970, and lead wasn't
finally eliminated until the 80s.
#49
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last as long as a modern engine you need to do a tune-up with the same frequency as you change oil. |
an old engine (rings, bearings, pistons) and then there's accessories
(carburetion, ignition). The internal hard parts are not terribly
different from today, but the accessories and lubricants ARE. That's my
real point.
I use a 1966 engine as a daily driver. I rebuilt it several years ago
and went back to a very stock configuration in all regards. The biggest
deviation from box-stock is that it has electronic ignition (a $100
investment and about 2 hours work) and that it has hardened valve seats
in the head (which only raised the cost of the overhaul by about $50)
It now gets about the same maintenance schedule as my wife's 05 PT
Cruiser. I recently had an oil analysis done on both, and the old engine
only had one wear metal that was higher (iron), probably attributable to
the fact that it's a 7+ liter V8 with more than twice the
ring-to-cylinder friction area and has the same volume of oil. Its
copper and lead wear numbers were actually LOWER than the 2005.
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Where is the evidence for these engines that burn or recess valves without leaded fuel? |
I had another engine (1966 383) that I converted to electronic ignition,
but it still burned 2 exhaust valves. At the time I was doing a great
deal of sustained high-speed driving with it. From the other old car
drivers I've talked to and my own experience, sustained high speed
operation is *much* harder on non-hardened valves than city driving.
Especially if you're starting with a higher-compression higher-power old
engine than something like a base slant-6 or 318.
I had a third engine (1969 440) in a restoration project that didn't
have any burned valves and still had great compression, but when I
pulled the valve covers for some work (all the valve umbrella seals were
rotted from age) and laid a straightedge across the valve stems, they
were all at randomly different heights- lots of recession on many of the
exhaust valves. So my quick saturday morning valve seal swap turned into
a valve job and more hardened seats. Actually, it cascaded into months
of work I hadn't planned to do for another year or so, but that's pretty
typical for my projects it seems... ;-)
#50
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jim <"sjedgingN0Sp"@m@mwt,net> writes: Matthew Russotto wrote: In article <-NydnQPDm9rTim7XnZ2dnUVZ_sGdnZ2d (AT) texas (DOT) net>, Steve <no (AT) spam (DOT) thanks> wrote: Also left out of the discussion is the fact the the VERY BEST motor oil you could buy in the late 60's wouldn't qualify as chainsaw bar oil today. Lubricants have come WAY further than engine design- at least in terms of bearings, rings, and other "hard" parts. Fuel managment systems have come as far as the oils or even further. If you could find a "pickled" (preserved, never run) factory engine from 1965 and put it into use with today's synthetic oils It would fail in short order without good old tetraethyl lead in the fuel; no hardened valve seats in an engine from that era. That isn't true. There was a lot of concern about that at the time of the switch over from leaded to unleaded. But just like the Y2K scare that problem never seemed to materialize. I know a guy who put 300K on a '49 willies jeep after lead was phased out without any valve or ring problems and no increase in oil consumption. I myself ran a '66 chevy 283 for 20 years after lead was gone and didn't have any valve problems. The real issue was lead was a lot cheaper way to boost octane than any thing else. The scare tactic was just to keep lead in gasoline as long as possible and it worked. If the problem had been truthfully posed as do we continue to spew lead across the country only to benefit the oil companies, then it would have been eliminated 20 years earlier. the exact same thing can be said of MTBE. In fairness, Y2K was a huge problem, but it was seen coming just barely far enough away that companies were able to put a huge amount of effort in and fix (or band-aid) their code so that almost nobody outside was inconvenienced. Had the work not gone into fixing it, the dire predictions would have come true. |
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Likewise my impression remains that the concerns about valve life were real, and not just oil company propaganda. But while the concerns were real, they turned out to be unfounded. |
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