Reg versus Premium Fuel experiament in 09 PT Cruiser
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From: Bill Putney on 6 Nov 2009 06:33 jim wrote: > ...No you are confused. The lead didn't cause any unusual wear to the valve > seats... I thought the opposite was being claimed. Did you mis-type there? -- Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')
From: Scott Dorsey on 6 Nov 2009 06:42 jim <"sjedgingN0Sp"@m(a)mwt,net> wrote: >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. 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 -- "C'est un Nagra. C'est suisse, et tres, tres precis."
From: jim on 6 Nov 2009 07:50 Bill Putney wrote: > > 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 > > -- > Bill Putney > (To reply by e-mail, replace the last letter of the alphabet in my > address with the letter 'x')
From: jim on 6 Nov 2009 07:56 Ashton Crusher wrote: > > On Thu, 5 Nov 2009 19:54:01 +0000 (UTC), Brent > <tetraethylleadREMOVETHIS(a)yahoo.com> wrote: > > >On 2009-11-05, Matthew Russotto <russotto(a)grace.speakeasy.net> wrote: > >> In article <-NydnQPDm9rTim7XnZ2dnUVZ_sGdnZ2d(a)texas.net>, > >> Steve <no(a)spam.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. 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. > 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. 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
From: Thomas Tornblom on 6 Nov 2009 08:00
Steve <no(a)spam.thanks> writes: > jim wrote: >> Ashton Crusher wrote: >>> On Mon, 02 Nov 2009 10:25:45 -0500, elmer <e(a)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 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 |