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Quote from: Murf on November 01, 2024, 10:59:00 AM A problem with a part synthetic oil could be bore glazing on a lightly used classic bike engine, I see a simple answer to that, Don’t Ride like a Pussy, they like a bit of a thrash😄I know this answer isnt SOHC specific but I think the same thing with engine oil apply to most classic Hondas.I really can't see any reason how a part synthetic oil or fully synthetic oil would have any bearing on bore glazing.The synthetic base oil is stable for much longer periods of time in an engine. They do this by making the base oil from scratch rather than refining crude oil. A lot of it is to do with the molecular structure of the oil itself, you have more linear molecules that are chemically the same as branch chain molecules. As crude oil has it's origins from plants (organic) there are a wide variety of oil structures within the oil - more branch chain than linear. With synthetic oil you manufacture the base oil using a stronger molecule that takes longer to loose it's essential properties as they use a stronger molecular structure as a starting point.Back in the 1960's ICI manufactured semi-synthetic petrol as a by-product of the chemical industries they had in the UK including the by-products from Town Gas & making smokeless coal before we converted to North Sea Gas in around 1971 ish.A gallon of ICI synthetic petrol was heavier than normal petrol due to having much fewer branch chain molecules so it was more dense. As a bonus it was also marginally better as a return on mpg. Once we had switched to North Sea Gas it was no longer economical to manufacture synthetic petrol. I have tried to simplfy the difference but there is an optimum length of carbon molecules involved. https://www.chemistryworld.com/features/is-synthetic-petroleum-the-missing-link-in-the-route-to-net-zero/4015785.articleI'm not sure if a gallon of synthetic oils is heavier than a gallon of mineral oil - I suspect it might be marginally denser. When Mobil1 was being developed they had a problem with the sulphur build up in engine oils over a certain mileage due to acid build up - the solution was to add micronised chalk to neutralise the acid.Aside from the base oil starting point most mineral & synthetic oils contain very similar additatives when they reach the oil can.Update - Diesel oil contains a lot more detergent to keep the carbon in suspension - hence why Shell Rotella turns jet black within a few miles after an oil change.
A problem with a part synthetic oil could be bore glazing on a lightly used classic bike engine, I see a simple answer to that, Don’t Ride like a Pussy, they like a bit of a thrash😄I know this answer isnt SOHC specific but I think the same thing with engine oil apply to most classic Hondas.
10w40 mineral motorbike oil is hard to find now, I and many other CBX 1000 owners use Valvoline 20w50 VR1 Racing mineral oil, however the original spec was a 10w40 oil same as the 550 and just about every other Honda at the time. There was just oil no special motorbike oil back in the day and I always used Castro GTX. The problem with the CBX and Semisynthetic oil is the clutch which can tend to slip, however if the friction plates are changed to a more modern material then the problem goes, so some owners do now use semisynthetic oil with seemingly no problem. A problem with a part synthetic oil could be bore glazing on a lightly used classic bike engine, I see a simple answer to that, Don’t Ride like a Pussy, they like a bit of a thrash😄I know this answer isnt SOHC specific but I think the same thing with engine oil apply to most classic Hondas.
