Peter Cobbold

John, AFAIK the ZDDP molecules remain intact but polymerise under heat and pressure to form a glass-like film on rubbing surfaces. The dithiophosphate moiety can be of several lengths allowing it to be tuned to different tmep/pressure applications. As there is one Zinc atom per ZDDP the ration of Zn to P will indeed vary with the oil type. A good level of sulphur ( in the 'dithio-' moiety) is another measure to look for, but it is not usually specified. Unoftunately the labelling by suppliers leaves us uncertain what they mean - as in the Iain's Motul oil above. The oil techies will know but

Summary document about USOs by a retired US Navy rear-admiral: https://thesolfoundation.org/wp-content/uploads/2023/07/Sol_WhitePaper_Vol1N1.pdf To me, USOs are just another example of 'impossible' matter-through-matter behaviour. Mtm is observed in UFO aductees passing through walls or celings, physical spiritualist mediums joining rings , poltergeist apports such as stones passing through walls. Mtm is thought to be impossible according to Pauli's exclusion principle giving matter its stability. But mtm is real. As Gallaudet says the stigma associated with UFOs and the paranormal h

""of high-Zinc (ZDDP content above1800 ppm)"" That is confusing. IF the ZDDP content really is 1800 ppm then Zn content would be around 250ppm- which is not 'high zinc'. IF the Zn content is 1800 ppm then the ZDDP will be about 7 times that ( because Zn is about one-seventh of the weight of the molecule). I suspect the scribes that write this stuff dont understand the chemistry. Peter

The blurb about Zn and P does point to a very good level of ZDDP. BUT the label on the container says "1500 ppm ZDDP: https://prnt.sc/nPUu7fG0cNVd I think Westway are confusing themsleves, and us !! Peter

Looks good to me. The similarity between the Zn and P figures suggests they are both in the ZDDP and not some other source of Zn. Peter

Ralph, The correct way of expressing the ZDDP content since way back is to measure the Zinc content of the ZDDP, in ppm. BUT over the past maybe 15 years some classic oil manufacturers/suppliers have used "ppm ZDDP". SInce the mass of zinc in the ZDDP molecule is only around 10% , the difference is large. These "1500 ppm ZDDP" oils have much less ZDDP than "1500 ppm zinc", allowing them to be used in classics with cats (ZDDP poisons cat convertors). Here's my post from 2017 when I first spotted the mislabelling trick: Nov 11 th https://www.tr-register.co.uk/forums/index.php?/t

The reason I use the 'cat-safe' criterion for ZDDP content is because there are two ways of stating ZDDP content that superficially look the same but actually are very different. "ZDDP ppm" is a lot lower ( maybe 10-fold) than "Zn ppm as ZDDP". So look for "Zn ppm" 1000-1500 region, as Mick says above. "!500 ppm ZDDP" is not enough. Peter

They are Willow Tits. It was only when they were in the hand ( for ringing) that id was definite. They are thought not to compete with other tits for food but the ringing session caught ca 100 all using the same table. Maybe they dont like hanging bird feeders. Peter

A pair of these has been feeding on the bird table all winter. Son in law and grandson are both 'ringers' so we know we have a pair. Mealworms odered. Its a red list species.

A rule of thumb: if an oil is stated to be safe for catalytic convertors, it does not have enough ZDDP for our engines' design.

Michael, I also question the use of a flow bench for tuning exhaust manifold on the basis that the air flow is not pulsatile. Tuned exhausts rely upon those pulses 'co-operating' to improve scavenge. No flow bench can do that. The only way I know of designing exhaust manifolds (pre computers) is to run an engine on a dynamometer and measure torque for several different fabricated manifolds. That would have to be done to compare the various TR designs. Peter

The problem with GT's flow-bench approach to exhaust design is that the exhaust gas is hot and his flow bench air was not. Gas temperature has a large effect on the speed of sound in the gas; in hot gas it is faster. That is one of the reasons why the ev can be made smaller than iv despite the much larger volume of exhaust gas compared with inlets. So gas-flowing an exhaust manifold with room temperature air will compromise, even invalidate, the design. https://www.engineeringtoolbox.com/air-speed-sound-d_603.html Peter

One CE3 from the French flap of 1954. https://ufologie.patrickgross.org/1954/10sep1954mourieras.htm Dozens of other encounters were reported that autumn across France ( click on CE3) Peter

Sudden eruption about 2 hrs ago. Live webcam: https://www.youtube.com/watch?v=YAQzsB9ev9Q

...watch this documentary https://watch.blaze.tv/watch/replay/382122 The UAPs ( aka UFO) that have been recorded on US Navy aircraft cameras are the tip of an iceberg. This excellent documentary covers many of the key sightings since the late 1940s. Dont miss Socorro, Father William Gill, and the Australian and Zimbabwe schoolchildren. Peter

There is a large amount of seismic activitiy going on at present under the Rekjanes peninsula SW of Rekjavik near the famous Blue Lagoon. This earthquake map updates every couple of minutes: https://en.vedur.is/earthquakes-and-volcanism/earthquakes/reykjanespeninsula/ This blog is a good source of info from locals and experts, scroll to the end of comments for latest thoughts, and links to data streams (eg GPS measurements of terrain uplift : https://www.volcanocafe.org/possible-runup-phase-at-fagradalsfjall/ Enjoy, but have a thought for the Icelanders' uncertainty. Peter