Reg versus Premium Fuel experiament in 09 PT Cruiser

So do consumers no longer demand that anymore??..

Which has proven to be a bunch of blarney. Maybe in an engine racing at
200mph it makes a difference but not an ordinary car.

Actually there were very accurate predictions made in the congressional
hearings in the 20's.

Except for ethanol. Lead never lived up to its claims. Lead didn't lead
to better gas mileage, didn't burn cleaner but they said they had
scientifc evidence it did.

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.

If you mean in the public in the thirties how was ethanol supposed to
get in their gas? It was prohibition and the oil companies and
automakers had already perjured themselves in front of congress
declaring there was no possible substitute for lead.

You gotta love that about ethanol. Despite the best efforts of all the
big players to make it look bad - it is the only one left standing.

Again ethanol was rejected for MTBE because it was just plain more
profitable for the oil companies. And ethanol is cutting into petroleum
sales. And the government and the oil companies again knew all about the
hazards of MTBE from the beginning and again the lies eventually didn't
hold up.


-jim

 

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.

 

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.

 

I bet most people aren't aware that today, lead is one of the powdered
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?

 

I thought the opposite was being claimed. Did you mis-type there?

 

I never said you implied that. I said that the lack of lead should in
fact cause unusual wear to the valve seats, so I am curious where the
added engine lifetime came from here. Cite, please?
--scott

 

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

 

That's BS. I suppose next your claim that when you rebuild an old
engine that protective lead coating penetrates even deeper than the
metal removal from grinding the valves. The protection of a lead coating
is Voodoo.

More BS. It is not as if valve seat recession didn't occur when engines
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

 

I don't know what you intended to write here, but I can tell you that
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

 

Possibly. A lot of people have run a *lot* of miles without trouble.
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.

 

That's probably true. Plus hardened seats were snuck into production a
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.

 

jim wrote:
The simple fact is that in order to make a 60's engine

OK, let's separate the problem here. Theres the hard mechanical parts of
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.

(raising hand...)

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... ;-)

 

You can't possibly believe that.

 

That's more or less true, but the question was what causes the wear on
internal engine parts. It has been shown that leaded gas at the levels
used in the 60's causes significant increase in soot and ash and some
increase in salts and acids in engine lubricants. And the difference is
not anywhere near insignificant in terms of engine wear.

So these are just case hardened seats not stellite?

That's not evidence. Hell I know somebody with a 2003 subaru that burnt
a valve at 60k. What does that prove?

The government of Thailand did some testing when they were deciding to
switch over to lead free gas back around 1990. They ran engines from
lots of different manufacturers (all asian and european) under high
speed heavy load conditions (since that was the only circumstance where
lead is supposed to make a difference). They found to there surprise
that some valves in some engines without hardened valve seats held up
better with no lead gas than others with hardened seats. Across the
board they came to the conclusion there was no significant benefit to
valves from lead. They also at the same time tested the additives that
are added nowadays to European lead free gas that are supposed to
replace the valve coating action of lead and found no significant
benefit with those additives either. The only thing that has been proven
conclusively is that lead raises octane.

I met a guy in the 70's that ran a volkswagon only repair shop. He was
from germany and VW factory trained in germany. He had been working on
VW bugs for 20 years. He claimed that none of his regular customers had
ever burned a valve in a vw beetle engine that he maintained regularly.
In fact he would guarantee it. Many of them getting over 200k without
any engine trouble. His secret he said was a tuneup and oil change every
1500 miles. I told him that was a pretty tall claim given that those
engines had a reputation for needing a valve jobs or more consistently
at 60k . He said that was easy to explain: at about 60k the diaphragm in
the vacuum advance would develop a leak. After that happens, drive it
another 5-10k and the next stop is the junkyard or an engine overhaul.
So the next time I was at a junk yard and saw a bunch VW bugs sitting in
the same area and I ask if they would mind if I did a little snooping
around in the beetle section. I checked about 20 vehicles and not a
single one had a working vacuum advance. So after that whenever I
happened to be at a gas station or a service garage or met anyone who
claimed to be a mechanic I asked if they ever heard of a vacuum advance
go bad on a VW or any other car for that matter. I never met a single
mechanic who ever heard of a vacuum advance going bad. A few were honest
and said they never had bothered to check if they worked or not. but the
vast majority just blustered something like "oh No those never go bad
they will last the life of the car" I guess that's sorta true.
I can tell you for a fact that sustained high speed driving with a bad
distributor or bad carb has a whole lot much greater impact on valves
than lead or hardened seats. Running too much fuel or too little fuel or
too advanced or to retarded spark at sustained high speed driving is
going to make the issue of what kind of valves or seats or fuel additive
completely irrelevant. The only significant effect that lead ever had on
fuel was its effect on octane.

-jim

 

And of course elemental lead and mercury have an entirely different
toxicity level than lead and mercury compounds. Handling or working with
metallic lead is very different from eating lead compounds in paint, for
example. A senior co-worker tells of how he used to bite the end of
leaded solder wire to flatten it when he was fabricating circuits back
in the 50s, and in my own generation we used to play with balls of
mercury dipped from the open-beaker barometer in the school science lab.
I don't recommend either practice and I'm glad we're more aware of
toxins these days, but it does make me laugh my head off when someone
panics and practically calls in the hazmat squad over the breaking of a
compact fluorescent lamp.

 

THAT is the single most overblown piece of misinformation out there. A
substantial percentage of the cam failures initially attributed to
inadequate ZDDP were in fact probably related to substandard material
and processing of a whole lot of lifters and cam blanks. That's a risk
when you're down to only one or 2 vendors still making flat-face lifters...

I'm running my flat-cammed Jeep and 1966 440 on SM-rated modern motor
oils just fine. So long as the cam is properly broken in (the first
20-minute run-in) with the proper break-in lubricant, ~800 PPM of ZDDP
is PERFECTLY good for everything short of extremely high-lift high
spring-pressure cams. And there are other additives now being used to
compensate for ZDDP. Don't forget that there is *still* a flat-tappet
cam test required for any oil to get an API rating, including the "low
phosphorous" SM rating.

 

Probably true, but then that falls in the same category as 60's oil not
being good enough to use in a weed-whacker these days. My whole point
was: given that these engines lasted >100k miles back then, it should be
no surprise that modern engines last even longer. Furthermore, OLD
engines built to OLD ENGINE SPECs also last far longer on today's fuels
and oils, even with carburetion still in play instead of fuel injection.

Beats me, I subbed that out to the machine shop. They're an
over-the-counter part specifically for vintage engines. Pressed in, just
like modern hard seats are done.

There are plenty of burned valves out there, not just mine. There is
also a known, understood, and well-described failure mechanism when the
valve seats are not sufficiently hard (microwelding leading to roughness
and erosion, leading leakage, leading to "torching" through the
valve/seat junction under peak combustion pressure). The fact that SOME
engines (probably the majority, in fact) never had trouble with unleaded
fuel doesn't invalidate the need for hard valve seats.

 

Having worked with software engineers who previously spent a fair chunk
of their career fixing Y2K problems before Y2K, I not only believe it I
KNOW it.

Anyone that thinks Y2K wouldn't have been a problem if corrective
measures hadn't been put in place is, frankly, clueless. It wasn't a
problem because a huge effort was committed to fixing it in time.

 

I appreciate your opinion. A lot of work WAS done, and a lot of money
was spent, and in the end there wasnt much of a problem, if any.

And the millenium passed, there was no apocalypse, no battle of Armageddon.
The next end of the world scenario, I understand, is supposed to be
11-11-09,
after which we will focus on the Mayan predictions.

 

Yes, I can. And I do. Here's an example:

http://news.cnet.com/Y2K-cost-estimate-cut-by-2-billion/2100-1091_3-235131.html

And, of course, that's the smallest estimate I've seen by a wide margin.
Here's another, quoting the Commerce Department at $100B.

http://www.greenspun.com/bboard/q-and-a-fetch-msg.tcl?msg_id=001nuR

I guess we can argue about whether these numbers are "huge" or not, but
not about how badly broken things would have been if it wasn't spent.