Author Topic: Zinc content in oil  (Read 4239 times)

Offline K2-K6

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Re: Zinc content in oil
« Reply #30 on: July 26, 2017, 10:12:05 AM »
It's something that's mirrored in each of the subjects like lead removal from petrol, Zinc removal from current engine oils and sulphur removal from diesel.

Each one of these has required consideration of the design,  metallurgy and lifing of engines and components in a changing of fuel and lubrication chemistry. Diesel has important anti wear / anti scuff properties that are needed to protect the pumps and injection systems used,  some of which are going over 500 Bar pressure, it's this characteristic that seems to prevent some neat diesel into engine oil causing damage. Probably less harm than mostly burnt combustion byproducts that go past the piston rings anyway.

This link gives a little look at what's going on in diesel fuel regarding sulphur content http://fueloilnews.com/2010/03/04/taking-the-mystery-out-of-lubricity/

I've no idea what they are adding to it to improve "lubricity" though,  can't seem to find anything published at all.

Interestingly,  I was speaking to someone working for a manufacturer assist scheme who said that in the event of missfuelling a diesel car with petrol,  they'd accept up to 25% petrol in the mix but would consider adding two stroke oil to avoid damage to the high pressure pump during run out. Then advise to keep topping off the tank with new diesel to swing the balance back to normal as it's used.

In cold weather environments it's been customary to add something like 10%petrol to stop the diesel going waxy. Fuel sold in those regions is normally supplied with integral "winter additive " now.

The environmental lobby doesn't really care if engines don't last long though as, in their view, the sooner you have to buy a newer one it will push the in use fleet faster toward lower emissions anyway. That's if you believe there are true verified improvements rather than false claims as to what new stuff outputs.

Offline Johnwebley

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Re: Zinc content in oil
« Reply #31 on: July 26, 2017, 10:55:55 AM »
I love this and other threads like this,

 the knowledge on this forum is wonderful

  PLEASE carry on !!!
lifelong motorcycle rider,and fan

Offline K2-K6

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Re: Zinc content in oil
« Reply #32 on: December 24, 2017, 11:56:41 AM »
Posting link to a very long thread that may keep you occupied over the holiday.

https://www.corvetteforum.com/forums/c3-tech-performance/3072456-motor-oil-wear-test-and-lab-test-data-7.html

It's a bit of a bun fight with some intervention to calm it down but quite interesting.

Post 140 on it gives a more detailed insight to how viscosity is specified and it's interaction with the engine regarding flow and pressure.

It's ZDDP focus generally is centred around camshaft and follower protection which being the original direction of this thread makes it relevant.

Offline Allington

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Re: Zinc content in oil
« Reply #33 on: October 01, 2018, 04:28:44 PM »
Really appreciate reading all this stuff K2-K6 . Just was this section was created for. Like 'Jensen' who I mentioned,  you may not get a flurry of responses as the info takes a bit of absorbing, understanding and reading around. But it's here as a great reference and easily accessible outside of the 'day-day' forum posts.

In the early 70's I had a Honda CD175A sloper. The local Honda dealer 'Ken Blakey' who had been a dealer since early doors waxed on about using 'Filtrate' oil in Honda's (dark grey because it has molybdenum disulphide in it). So, at great expense, I replaced the 175 oil with Filtrate oil  but at the next oil change I cleaned the centrifugal filter housing and was shocked to find so much black stuff in the housing that there was only a pencil size hole down the centre.  So what was all that about? Does anyone else have experiences with Filtrate oil (it came from Leeds)?

The Honda main dealer on the Isle of Wight (Dave Death) in the 70’s used Filtrate oil in all new bikes. In fact apart from 2 stroke oil it was all he sold.
"A little bit of knowledge is a dangerous thing..."

FS1E - RD200 - CB500 - Norton Commando - Z900

Offline Bryanj

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Re: Zinc content in oil
« Reply #34 on: October 02, 2018, 01:49:52 AM »
We used to use solely Filtrare bought from Popes Suzuki dealer in Bristol cheaper than direct as he bought a full load at a time. Eventually went Castrol as use increased as they supplied the bunker bin

Offline masonmart

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Re: Zinc content in oil
« Reply #35 on: December 20, 2018, 12:57:54 PM »
My own conclusions, as a process engineer in the oil industry and having read a lot on the subject to educate myself, are that there should be no need to add zinc additives. The key to protecting bike engines is to use modern oil and to change it regularly. It is not true that modern synthetics are not OK for classic bike engines, on the contrary they are the best oil to use because of viscosity range and that they keep wear surfaces wet with lubricant. There are some myths that need to be nailed if we want to be as sympathetic as we can to our engines. Monograde like we used in the old days are not fit for purpose, they just happened to be all that was around. Non-detergent oils  should never be used. Modern petrol doesn't produce sludge like in the old days just fine particulates that will be kept in suspension until the oil is changed and thrown out with the oil. These particulates are too small to be removed by the oil filter.

Offline Nurse Julie

  • 1973 CB750 UK K2.1977 CB550/4 Mongrel Brat. 1978 CB400/4.
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Re: Zinc content in oil
« Reply #36 on: December 20, 2018, 01:17:56 PM »
I'm not getting in to the debate about zinc in oil as I know diddly squat but, fully synthetic oil on a wet clutch system does lead to clutch slip, especially on CB400/4's . For this reason I use semi synthetic in all my engines, once run in if rebuilt (mineral for the first 500 miles). I still think the best we can do for these old girls is change the oil regularly.
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline masonmart

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Re: Zinc content in oil
« Reply #37 on: December 20, 2018, 02:04:36 PM »
I'm not getting in to the debate about zinc in oil as I know diddly squat but, fully synthetic oil on a wet clutch system does lead to clutch slip, especially on CB400/4's . For this reason I use semi synthetic in all my engines, once run in if rebuilt (mineral for the first 500 miles). I still think the best we can do for these old girls is change the oil regularly.

Nurse Julie, the oil spec that has the potential to cause clutch slipping isn't synthetics, it is oils that have had friction reducers added or what they call power maintenance grade. Wet clutch bike engines use the equivalent of JASO MA2, cars and bike engines with dry clutches use MB grades. It isn't correct that using car oils in bikes does cause clutch slip in fact it is very rare but it does increase the potential. Semi Synthetics can be a waste of money as the best non-synthetic oils easily meet the specs. I believe, although I could be moved, that running in oil is a waste of time and even regimented running in a waste. Interesting.

Best wishes.

Offline Nurse Julie

  • 1973 CB750 UK K2.1977 CB550/4 Mongrel Brat. 1978 CB400/4.
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Re: Zinc content in oil
« Reply #38 on: December 20, 2018, 02:33:11 PM »
Agree, running in oil is a waste of money. Disagree about running an engine in in a regimented way. It does depend on the work carried out on the engine of course and what parts have been replaced. The more machine work carried out and the more new parts fitted, the more regimented the running in process. I only ever run in old bike engines, newly rebuilt or overhauled, properly. Modern day bikes and cars its up though the gearbox once and back down again, as far as I'm concerned, it's then run in 😀😀
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline masonmart

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Re: Zinc content in oil
« Reply #39 on: December 20, 2018, 04:15:15 PM »
Agree, running in oil is a waste of money. Disagree about running an engine in in a regimented way. It does depend on the work carried out on the engine of course and what parts have been replaced. The more machine work carried out and the more new parts fitted, the more regimented the running in process. I only ever run in old bike engines, newly rebuilt or overhauled, properly. Modern day bikes and cars its up though the gearbox once and back down again, as far as I'm concerned, it's then run in 😀😀


Julie, there have been a lot of very good papers written saying that running in has little benefit. The best article that I've read explained that for a modern rebore and honing that all of the wear that is going to happen does so in one heat cycle where the engine is bought up to full running temp and during that period there are no specific rpm guidelines but that the engine shouldn't be under or overloaded and if possible revved reasonably hard. This is because the only surfaces that need running in now are the rings. A heat cycle is approximately 20 miles. It's always been said that this produces more power at all revs but reduces life but that doesn't add up at all. I recently asked some lads who race classics what they do and they say that the engines are run in after 10 laps which is about my 20 minutes.


In days gone by you had to run bikes in in a regimented way because the boring and honing were much lower quality but in the new bikes and cars I've had there is no recommendation to run in. This is done during the running test in the factory. It's like oils, things constantly change and we are conservative and tend to not want to change 8)

Offline Nurse Julie

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Re: Zinc content in oil
« Reply #40 on: December 20, 2018, 04:45:25 PM »
All very interesting stuff. Yes, a full heat cycle is essential, preferably on a nice cool day with an air cooled engine. What you have read about about running in with not too much or too little load and revved reasonably hard is the way Graham (Trigger) advises me to run in all my engines on the old Honda fours but I have to do nearer 100 miles if possible, not just 20 miles  :'( :'(
I think as long as the engine isn't cold and doesn't have it's nuts thrashed on the maiden voyage, I think all will be well. I also feel the most important part of the whole process is the oil and filter change at 500 miles and checking and cleaning the sump and the oil screen to remove any small particles of metal debris from the wearing in of new components fitted when the engine was rebuilt.
Also, as I am a totally compliant person (shut up at the back of the room  ;D) I always do exactly what Trig says, what with him being a professional specialist Honda SOHC/4 engine builder / refurbisher, I wouldn't dare do anything other than what he advised.....I could not handle the resulting flack if I messed it up 😀😀😀
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Offline masonmart

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Re: Zinc content in oil
« Reply #41 on: December 20, 2018, 05:28:22 PM »
I'm sure I would too Julie, I know my limitations and respect people like trig who are genuinely good at what they do. I'm a qualified engineer but I know I'm not good at mechanics as I have a tendency to rush. I have tended to get any difficult work done by a very unassuming friend who built a 3 cylinder, 375 cc, water cooled Ariel Arrow from 2 x 250 cc air cookled twins.