Reg versus Premium Fuel experiament in 09 PT Cruiser

The wagon wheels with metal treads have an order of magnitude less
rolling resistance too - so better fuel mileage, but of course their
traction (cornering, accelerating, braking) sucks. Sounds like a
gubmint solution to some serious problems - something Al Gore and Obama
might be interested in having legislated (except, of course, Congressmen
and Senators would be exempt from having to use them).

 

But that is a result entirely of the electronic improvements. It is not
as if the tighter clearances couldn't have been achieved in the 60's.
But if you have an engine that is producing internal carbon deposits
tight clearances can be fatal to engine life. It is not as if those
clearances used then were not there by design. It was possible to make
engines with tighter clearances in the 60's but tests showed that
brought with it a bunch of reliability problems.

I suggest only substituting the parts that were really making the
difference to illustrate a point. Conversely you could take an engine
from the 60's and put a modern fuel and ignition system and if done
right it would eliminate the ring and valve problems that you claim are
inherent from a weak engine design.

What is different today is the engine management system and
manufacturing management systems. One of the results of all that is
cheaper materials go into building a car. For instance, in a car there
is a lot less metal all around. That extra metal that used to be in cars
40-50 years ago was not making the car weaker as you claim. The simple
fact is that an engine of the 60's could be expected to spend a
considerable amount of its life running with the timing off the mark and
the fuel mixture out of balance and an unpredictable amount of carbon in
the cylinders. In order to make an engine last under those variable
conditions it had to be over-engineered. That over-engineering
disappeared as the electronics got better and better.

Don't try to change to a different argument because you think you lost
this one. I was disputing your incorrect assertion about engine design:

"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."



The cause of valve and ring problems of which you speak can be entirely
attributed to the fuel and ignition management used back then. Back
then, an engine that was meticulously kept in tune lasted much much
longer than 100k. But most engines weren't.

-jim

 

That might be your problem. The immediate readout on most cars is based on
throttle position and not on actual fuel metering. If there is a way to
reset the display to defaults and let it relearn, try that. To really know,
you need to get out the old paper & pencil and calculate it over a few tanks
of gas.

 

Be careful what you say. If Gore overhears you he'll want to mandate
that we all switch to nitrogen filled tires with heavy fines for using
"air".

 

No it wouldn't. If you used the original factory rings and
non-hardened valve seats and all the other factory parts of the day
you would continue to expect early burning of valves and early wear
out of the rings.

The keep talking about how if you CHANGE things on the old engines you
can make them better. Well DUH. And how if you CHANGE things on new
engines you can make them worse. DUH again.

Now you have wandered off into the entirety of the car rather then the
engine. But if you want to see how far off the mark you are go watch
this crash test of a big ol heavy full of metal 59 bel aire against a
much smaller cheaply made modern car


The simple

They weren't over engineered. The basic block and heads were very
similar to today's cars except that aluminum was rarely used.

I don't think I lost this one since I'm obviously right and you are
living in a fantasy world.

Sorry but you are wrong overall.

 

I've already done that and the readout is very close to the total tank
average. And as I said, my main comparison is steady state driving,
constant speed, on the same road with the two different gas's. It
will give an accurate relative difference between the two gas's but
both might be 0.4 mpg low (or high). The last tank pen and pencil
average was 25 mpg whereas the computer said 24.6.

 

Hmm - what if we mandated that you had to fill all tires with CO2. Gore
could have an exclusive franchise on the special equipment that would be
required at every filling station and tire servicing facility in the
country that would separate out CO2 from the ambient air for people to
use to inflate and top off their tires. That way we could starve the
earth and those pesky plants from that awful CO2, and an entire industry
(owned and controlled by Gore, and taxed by the gubmint) would be
created - a new job stimulus program that would shuffle money around and
accomplish nothing like everything else they are trying to do - another
entire false economy built on the "merchant's broken window" principle.

This should be made part of cap and trade - OH - I'm sorry! I forgot
the new euphemism for that is the "Clean Energy and Security Act".

 

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

 

Stupid "send" button ;-)

If you put it into use with today's synthetic oils, you'd find that it
runs as long or maybe longer than anything modern. If my '66 engine went
180,000 miles with the kind of "group 1 or less" oils it had early in
its life, imagine how well it would do with group IV synthetics right
out of the box.

 

No. They're not. Bearing, ring gap, and piston-to-bore clearance specs
on my '1966 and 2005 engines are virtually identical.

THAT is true, but has nothing to do with "strength." That's airflow
design (manifolding, heads, chambers, valves) and fuel management (EFI
instead of carburetors).

 

The PT used the 2.4 DOHC engine as the base version, the turbo 2.4 DOHC
was the option. Same engines as the biggest Neon option. The Neon came
variously with the 2.0 SOHC, 2.0 DOHC, 2.4 DOHC, and 2.4 DOHC turbo.

 

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 turned out to be a very overstated problem; the valve seats would
last a long time without lead. OK, a valve job would be needed long
before anything else on the engine needed replacement, but that would
still be after many miles.

 

I'm not so sure about that. it seems that such wear isn't as bad as was
once believed.

 

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.


-jim

 

Hey, Stellite!. Stelliiite!! *

*with apologies to Tennessee Williams

 

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.

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.

 

Both my '65 Corvairs do, stock.

 

Effective propaganda may produce real concerns. But consider the facts -
It was well known that lead was a poison when it was first added to gas
in 1920. and it was well known that lead is a substance that never
biodegrades when it is placed into the environment. It turned out that
there were considerable financial advantages to the automakers and oil
companies but hardly a shred of true evidence there was any advantage to
the consumer or driver of cars. Yet most people had been convinced it
did have advantages. But your right this wasn't oil company propaganda
The serious lying came from the auto manufacturers.

The lead in gasoline got there by agreement between Congress, auto
makers and oil refiners. The automakers wanted higher octane fuel the
oil companies didn't want to bear the large expense of the extra
processing to make high octane fuel. Back then it would have more than
doubled the cost. The deal they arrived at was simple. Put lead in the
gas. To sell this to the public the automakers would claim that their
cars would fall apart without lead and congress and the oil companies
would go about selling the public on the health benefits of lead in
gasoline.

The main reason that the automakers made a big deal out of coming out
with newly designed valves and other components when unleaded fuel was
first started to be sold in the 70's was that they had claimed 50
years prior that they had a mountain of scientific evidence that bad
things would happen to engines without lead. They couldn't now just
ignore those claims they had stated as scientific fact. Modern studies
have revealed that those early studies were probably complete frauds.
One 2003 study showed that adding Tetra ethyl lead to gasoline reduces
engine life by 50%. 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.


One interesting side note is the role ethanol played in this. Initially
the oil companies rejected the idea of creating higher octane fuel by
adding a well known poison to their fuel and told the automakers to take
a hike and they didn't give a damn about octane that was the automakers
problem not theirs. After all why should they compromise the image of
their product for the benefit of the automakers. So automakers (mostly
ford & GM) started fooling around with mixing ethanol as a fuel. That
got the oil companies attention and suddenly the oil companies saw the
light and started supporting the lead additive. Ethanol as a fuel
disappeared for quite a while. It took 80 years and 7 million tons of
lead blown out the tail pipes of cars but eventually ethanol made a come
back.


-jim

 

No, there were _major_ advantages to ethyl. It not only made high octane
gas much cheaper to make, it made high octane gas _practical_ to make.
Yeah, it's possible to make 90 octane gas from casing head, but it evaporates
right from your tank and it's substantially less safe to transport.

Higher octane gas means higher performance engines for the consumer, and
the consumer demanded that.

A side effect was the fact that valve seats lasted a whole lot longer
because of the lubrication the lead provided.

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. On top of that, nobody had
any idea that the auto industry would explode to the point where emissions
were a big issue.

In retrospect, it turned out to be a bad idea, but I don't think you can
blame folks at the time. For a while, you could buy gas with and without
ethyl; they coexisted in the marketplace. But as I said, it's just not
practical to make high octane gas without an octane enhancer. And the
first convenient one that was found was lead.

I'd like to see a cite to that 2003 study. I'd also be curious if that
study used an engine with modern hardened valve seats or typical 1960s
soft seats.

Again, I have seen plenty of ads from the thirties promoting ethyl in
gas, but I have never seen any of them promoting ethanol in gas. I'm
not sure anyone ever knew about it in the general public.

Ethanol didn't make a comeback, though, until after lead was replaced by
MTBE, and then MTBE turned out to be even worse than lead was.
--scott