Honda-SOHC
SOHC.co.uk Forums => Anorak's Corner => Topic started by: AshimotoK0 on June 18, 2017, 12:52:36 PM
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A guy called 'Oldgeezer' on HondaTwins.net posted this comment to a guy who's top end was toast when he took the cam cover off (looks like a CB360/CJ360 engine). I have never heard about zinc content or additives before. Any ideas? I am not well up on oil technology myself.
Quote from 'Oldgeezer'
"What oil have you been using? It needs 1200ppm zinc to keep cam ware in check. Valvoline VR-1 & Mobil 1 4T has proper amount. Car oil only has 600-800ppm. When you install a new cam, use zinc booster to raise zinc to 1700ppm for 500 miles, then replace the oil with standard 1200ppm".
I found this :
http://www.ebay.co.uk/itm/Edelbrock-1074-High-Performance-Zinc-Additive-Engine-Oil-Supplement-/111931607231?hash=item1a0fa4c8bf:g:nc4AAOSwu1VW4Whu
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Isn't that why Brian uses Diesel oil?
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Spooky connection here Ash as I read your post over on the black bomber thread this morning and thought of this subject and of opening a thread about it.
Usually listed in content as ZDDP, Zinc Dialkyl Dithio Phosphate, it has some pretty unique properties and effects, especially for older engines.
It's now being almost totally excluded from modern engine oils as when passed into exhaust stream it will have a destructive effect on catalytic converters and the like.
Basically it floats around in engine oil and just exists without doing much until it comes under extreme mechanical pressure in situations like camshaft lobes. It typically prevents metal spalling and pickup (the destruction of machined surfaces) when the shear capability of the oil is exceeded and can have a hugely important function in preventing wear starting.
I'm a fully paid up, anorak wearing advocate of ZDDP in oils ;) as I look after a number of engines that would be considered in need of specific consideration in this regard.
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Spooky connection here Ash as I read your post over on the black bomber thread this morning and thought of this subject and of opening a thread about it.
Usually listed in content as ZDDP, Zinc Dialkyl Dithio Phosphate, it has some pretty unique properties and effects, especially for older engines.
It's now being almost totally excluded from modern engine oils as when passed into exhaust stream it will have a destructive effect on catalytic converters and the like.
Basically it floats around in engine oil and just exists without doing much until it comes under extreme mechanical pressure in situations like camshaft lobes. It typically prevents metal spalling and pickup (the destruction of machined surfaces) when the shear capability of the oil is exceeded and can have a hugely important function in preventing wear starting.
I'm a fully paid up, anorak wearing advocate of ZDDP in oils ;) as I look after a number of engines that would be considered in need of specific consideration in this regard.
Wow ... brilliant reply .. I knew somebody on here would be well up on it.
There is a Dutch guy too on HondaTwins called 'Jensen', who lets put it as politely as I can "does not suffer fools gladly" but his tech posts (anoraky if you insist) make wonderful informative reading. He did a whole set of posts on running the Black Bomber K0 engine on fully synthetic oil. Kettle738 on here (Mick) told me that the early bomber oil pump wasn't very high capacity and the last lobe to be fed on the twin cams tended to suffer from pitting etc. (exhaust cam)..... Jensen also identified this and hence his 'trials'.
http://www.hondatwins.net/forums/55-engine-discussion/33075-full-synthetic-oil-fresh-build-cb450-k0-engine-mile-0-a.html
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It'll take me a while to read through that, seems really interesting with him offering a very factual account of what happens rather than speculation.
It's funny that oil has such a small remit, to stop the engine wearing with part of that to keep it cool, but such a massive subject to discuss and achieve that.
As Jensen says though, it's sometimes difficult to discuss on forum without being deluged by other's assumed information and just plain preferences not backed up by scientific data of any real standing. I can see his point in taking his time to write intelligently about it and having non qualified criticism dispensed would make you not want to bother. Looks like he's making a valuable contribution.
I don't mind posting what I've worked through and hope we may be left alone over in anorak's corner to go through various areas of the subject if you're up for it. :)
I believe that the best solution to protect any engine should be up for discussion with nothing taken off the table for spurious reasons.
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Fire away ! This section was created by Steve to allow this type of discussion. I won't be much use here though as I know very little about oil technology but agree it's the lifeblood of the engine and warrants an in depth discussion. I am pretty sure Bryan will have an input too.
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I've got to page 7 of Jensen's posting, some very interesting additions coming in there.
Both you and Mike in an early post reference Bryan's view on oil for these old bikes, I think he's right on the ball for getting that spec to people asking the, what oil should I be using question. For people wanting a straight up recommendation it couldn't be more simple, and those oils mostly would have a zinc component as they have no attachment to current engines which effectively have their oil components legislated via emissions regs etc.
I think here we should look at if anything better is available and if so, why. Hopefully it may even get some more insightful contributions to debate.
I'll get off and read the rest of the Jensen case study to see where he got.
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I used Silkolene Transfleet 10w40 commercial diesel oil because it had the same specs on the tin as Honda wrote in the handbooks for all the sohc motors, also the transport firm i worked for used it in there trucks so it was free---the modern ones use fully synthetic long drain(200,000 Km) oil which is no good for the bikes but works fine in the L200 and Peugeot 406HDI
Silcolene is now Fuchs and i have never had a decent reply as to what is the equivalent of the Transfleet but not bothered as i have about 40 gallons stashed---should see me out
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I've got to page 7 of Jensen's posting, some very interesting additions coming in there.
Both you and Mike in an early post reference Bryan's view on oil for these old bikes, I think he's right on the ball for getting that spec to people asking the, what oil should I be using question. For people wanting a straight up recommendation it couldn't be more simple, and those oils mostly would have a zinc component as they have no attachment to current engines which effectively have their oil components legislated via emissions regs etc.
I think here we should look at if anything better is available and if so, why. Hopefully it may even get some more insightful contributions to debate.
I'll get off and read the rest of the Jensen case study to see where he got.
All hats off to Steve for creating this section because on other sites, this techy info gets buried or lost and hard to locate. There is a wealth of info on the USA site and also HondaTwins.net but it's sometimes extremely difficult to locate. BTW 'Jensen' is also on Honda305.com but has had to switch to 'Jensey' because his original identity got lost somewhere down the line.
Lets all work to make this section and the Dropbox links for documentation an easily accessible 'go-to' for tech stuff on our bikes
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I've finished reading Jensen's post to date, it may be worth discussing that in a separate thread to avoid some of the very interesting stuff getting lost in just straight oil subject.
To talk more about ZDDP and how it relates to other additives, http://www.experimentalaircraft.info/articles/engine-lubrication-6.php given a front end overview of the different properties we can consider.
Basically, as I see it, the zinc interaction is really the last line of defense for our metal components in situations of the oil film breaking down. Know as anti wear, and trying to prevent damaged in very extreme circumstances.
Friction Modifiers, principally Molybdenum disulphide, work in the area of duress prior to reaching "extreme " and it is this component I feel is undesirable for our wet clutches. It appears to be accumulative, so could build up in clutch materials and promote friction release, which we don't want.
Commonly listed as Molly, Mollyslip, Modtc etc in oil listing.
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https://en.m.wikipedia.org/wiki/Extreme_pressure_additive
There's a crossover into EP gear oils that touches / borders the discussion of inclusion of ZDDP in engine oils, not necessarily applicable to our engines but it shows a little more of the scope and interaction with some of the compounds used and helps to form a picture of what's going on.
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I had mate who's brother was an oil blender, both were big fans of Molly. They talked me into ignoring the warnings and trying a Molly additive in an automatic gearbox and a couple of bikes with wet clutches. I really couldn't do their arguments for it justice, but I recall that it mostly related to how it bonded to materials (including that it wouldn't bond to itself unlike ptfe) and that it would help avoid getting to the extreme situations were zddp helps. Added over a few years every oil change it didn't cause any clutch slip.
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It seems to be very good at friction reduction but I've always kept away from use with wet clutches.
You don't have any contact with the original persuaders do you? that may add to our thread.
I've seen it put into manual car gearboxes and all but prevent the synchro rings working as it changed the friction they impart so much that it puts the gears at risk as the synchro function just didn't spin up the opposing gear sets to match their speed. It's probably these things that have formed my view as to how slippery it is.
I've read alot from this source https://bobistheoilguy.com/whats-in-your-motor-oil/ and there's is so much material out there relating to this stuff.
Another key that gets into all sort of ZDDP analysis is to search for it with "flat tappet cams" you'll be deluged with camshaft specific experiences surrounding it's use, effects and levels of desirable content.
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No, sadly he died a few years ago, but he would have been all over this, he loved a good oil thread.
The tickover rose on one car when I added Molly, definitely slippery stuff.
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I wish I could understand what was going on my brain keeps turning to mush. :-[
The way I understand it ZDDP is a last resort in the oils defences so if its changed often enough it should never be needed.
I think the most important thing is to use the right grade and change often.
Feel free to correct me if I'm wrong it wouldn't be the first time.
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I feel like that as well, have to think about one part of it at a time else brain goes to overload :)
It's partly right in that if you keep the oil in good condition you are less likely to break through its structure. But that is balanced by some engines having a camshaft loading so high that the oil, even in new condition, will only just about survive the loading it takes.
Fortunately the SOHC fours have well designed and considered valve gear geometry on the whole which will mainly not give problems, but, it's easy to make any engine step over that limit. One way is to have valve clearance too small, this does not allow the oil film to re-establish on each rotation of the cam so the depleted oil supply as the follower comes up on the ramp it breaks through the oil and gets metal to metal contact.
Another easy way is to keep running the bike alot on choke with no long journeys. The oil is quickly diluted with part burnt petrol and other contaminants from rich combustion, this very quickly trashes the oils shear properties and offers low protection to the cam.
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Don't forget when we use the oil it is getting hammered as gear oil as well
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At first appearances it looks like that just because the gearbox looks so gnarly, it gives the impression it would badly affect the oil. But different gearboxes are designed to run on different types of oil which if done correctly will not adversely cause any real harm to the oil.
Most gearboxes with their own oil will run many thousands of miles without changing the oil, it's the combustion by-products in mixed systems that prematurely degrade the oil with the risk opposite to how it's commonly perceived ie, dirty diluted oil puts the gearbox components at risk.
I've thought through about your point Mick, about anti wear properties (talk about taking one thing at a time) the oil film is likely to be breached each time a motor is started. When it's turned off and left then the oil that was in the bearings partly leaks away, then when you go to start it again you are reliant on the anti wear properties to prevent damage and metal pickup until the oil pump has pressurised all the bearings again. As soon as that crank starts rotating and the big end gets thumped by the compression it won't have the desired pressurised oil film to protect it. The cam is also under valve spring pressure / load right from the off, whether any oil is there or not.
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Isn't separate gearbox oil which is ran for high mileages normally single grade?
I'm sure I'd read somewhere that gearboxes break down some types of viscosity improves used in multygrade oils, causing the oil to get too thin at high temperatures.
There's another consideration but I'm not sure if it's just marketing hype, which is extreme pressure (EP) additives. Gearbox oil is typically marketed as EP oil, they used to market specialist EP oils for A Series engines due to them being one of the few cars with the gearbox sharing the engine oil, and it used to be one of the justifications for bike specific oils being required.
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Each gearbox would by designed from scratch to use a different type of oil, an ep oiled box and most differentials will take advantage of that level of protection by asking it to transmit a higher level of torque for a given component size and ratio change.
You're right that gearbox specific oils are often monograde or restricted viscosity range eg 75/90. But one of the main differences is that gearboxes mostly don't have a pumped system of distribution so that you don't run into cold oil hydraulic locking the pump as all the components cope with torque ratings far in excess of that needed to move sticky oil around. It'll just cause drag and power loss until warm.
Compare this to an engine, they have to pump oil round to all components so by default need to run a pump. Most engine oil pumps if you started with mono / hot grade oil 40 for example will be at risk of hydraulic pressure overwhelming the oil pump drive if you started it in zero degrees, this is why before multigrade was available you'd have to tailor your oil viscosity to cope with seasonal temp variations.
The Mini combined system may have benefitted from a heavy duty or extreme pressure denoted oil as you say but I think this is nothing more than a zinc heavy bias to the additive package, like the original post title asks about.
There are other examples of boxes running engine oil. The original range rover 4speed was designed from scratch "lt95" to do this and incorporates a pump to lubricate it, you can't run something like ep90 in these for risk of shearing the oil pump drive.
The add package components in transmissions oils I don't think are in any way suitable for use in engines. They use things like sulphur, that although being resistant to some heat in normal use won't tolerate direct surface contact in places like cylinder heads as I understand it.
Something else component wise that look like it benefits from ZDDP are the internal chains, both cam and primary drive. The size of the bearing surfaces and torque going through the primary are candidates for bringing oil film on its own to the very limits of protection via the pressure they're able to exercise.
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I wondered if anyone else would dig up some interesting stuff in this area, but thought I'd add some more.
Like you've done with the mini transmission Totty, I use different application to help me explore some of the limits of this subject, makes for interesting comparisons of why the original design and specs called for some particular oil or procedure.
Following is why ordinary transmission don't necessarily need a heavyweight EP oil of the type commonly used in differentials. Generally gear tooth design places the meshing teeth very carefully against each other as they come into contact, with very little sliding between the faces coming into contact. It's sliding metal to metal that causes the most stress to oils. Wether the gears are straight cut or helical makes no real difference as far as I can see, helical just being quieter than straight as it's less prone to set up a resonance pattern with each tooth taking up drive slowly rather that all at once.
The need for those transmission oils specifically labelled EP comes from Hypoid gear arrangement used most commonly in axle differentials. What that design does is to take the pinion centre and offset it from the crownwheel axis. This involves a tooth design that is hyperboloid being a cross between a worm drive and a plain pinion. It's this design that has a very high amount of sliding between the gear faces and as such requires the special adaptions within the oil to resist oil breakdown and total destruction of it's shear quality that would effectively wear the metal. The advantage of using a Hypoid design is that the pinion can be much larger than a straight on axis design but without increasing the crownwheel diameter, this keeps the diff compact while allowing a high torque capacity in as small a space as possible.
Notably, the old Mini transmission, I think, drives from it's final drive onto the differential cage without any Hypoid gears, it's this aspect that makes it a technical oddity and doesn't require special oils of the degree discussed above.
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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)?
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Some mention of it here . Perhaps it was colloidal graphite not moly.
http://www.voc.uk.com/net/docs/4.2/4.2-437-20.pdf
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As Totty says, they are very different as I understand it.
Our modern use of graphite is most commonly found is Graphogen used as an assembly lubrication particularly for cam lobes and followers, but as you found not applicable to general oil use for our bikes on this forum.
I've some interesting back stories of filtrate etc which I'll post next, just got go out and collect my daughter from school right now.
Nigel.
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Apologies Ash, I got my poster's mixed up there.
I understand it as that voc letter places it, the oils of that time when it was mostly in use were non detergent type so you expected the contaminants and particals from use to drop to the bottom of the sump to be drained out at change time. I'm not that knowledgeable about pre sixties oil filtration systems but ones I've seen have been fairly rudimentary in a basic gause type that would just stop any chunky bits going round again and leaving the graphite in its colloidal distribution to go round undesturbed.
For those looking information, this may help to place what they mean by colloidal.
http://www.whatiscolloidal.com/colloidal-definition/
I guess the Filtrate name effectively refers to a whole package that fits with the engineering of the time in working with contaminate dropout and preserving the additive it would do what they claimed. But as you found with a centrifuge oil filter (likely to be paper filter type as well) the engineering design effectively obsoleted their method. Curiously, a centrifuge filter could possibly out perform a paper type with a solution like that.
Interestingly, most car CV joints use that type of lubricant nowadays, embedded in grease, as it has some very long lasting non volatile properties that are very effective.
I've an odd connection with Filtrate also as my father swore by it for use in a Vincent Black Shadow he owned and raced. He got a third place on it in the 1953 TT 1000cc class using that oil which was provided to him by the factory. Think I've still got the letter of agreement from the oil factory.
More recently, I was standing talking at a bike meet to someone with a Vincent Black Prince, and was recalling my father's bike of which I new the reg no, he made just one phone call to someone that knew of Vincents currently owned and that person is the current owner of my father's bike. What a stunning coincidence.
Nigel.
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When i worked for Frazer in Glos we used to buy Filtrate 10w40 in 5 gall drums from the Suzuki dealer in Bristol (Used to sell pushbikes as well) as he bought it by the truck lload and it made it cheaper than anybody elses for shop use and met Honda specs. Dont remember any collodial graphite in it though
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I think there are, as you say Bryan, two distinct parts to that story as filtrate. The normal oil that the brand name applied to and the colloidal graphite stand which may have been incorporated into the oil in earlier years or added as a package to any oil from a separate can to, in effect, dose your oil of choice.
I guess that with the advent of more complete filtering systems the days of adding something of that partical size to engine oil would largely disappear. As Ash found out then, it will all end up in the filter system.
There was an interesting documentary last year on the graphite industry centred around Whitehaven in Cumbria, as they found that molds for cannonballs when coated with it enabled a particularly clean release of the cast balls. This allowed them to be made much closer to consistently spherical, this along with then allowing a much more accurate choke in the canon barrels vastly improved our naval warfare capabilites with the attendant outgunning of opposition.
More relating to the bikes on this forum, I don't consider anything ( certainly within the 4 cylinder bikes) mechanical to give the oil a hard time resulting in oil condition deteriorating to the point that it would be considered unable to lubricate properly.
That doesn't mean that something else is not in operation that does.
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To move on from the mechanical effects imposed on the oil in these bikes, I feel it's the combustion strategy that causes the oil life to be quite short.
There's a basic problem running multiple slide carbs to fuel these engines. I can taken a guess as to why the design originated, Honda's mimic of their sixties race bike technologies leveraged, in marketing terms, to deliver road versions of that track success. Pretty good it is too.
With one carb per cylinder there is no air volume passed through that carb except for its own cylinder, obviously, so the vacuum can't be moderated as perhaps a single carb for multi cylinder would. In addition, a simple slide carb has what I'd consider to be "symmetrical " fuel metering in that it's a straight correlation of air vacuum to the amount the main jet is allowed to flow by it and it's needle geometry.
This is where it gets more interesting. For complete burn of fuel you need an ideal ratio of 14.7 parts air to 1 part fuel ( think that's right) and which is known as the stoichiometric ratio. If you don't run this, and many engines don't, then any excess fuel is not burnt which leaves it to go out of the exhaust port or past the rings into the oil.
The specific problem with slide carbs as fitted to many of these bikes is that to get the engine to accelerate well then you may need to get down toward 11 to 1 ratio to light it up and make it respond fast to the throttle being opened, and if you jet it like that it'll have to run at that ratio even without load, ie trickling along on part throttle. I think it's worse than that though, to get the mixture rich enough to respond well is also tempered by the transient characteristics of this carburettor arrangement. If the engine is running slower revs and you open the throttles wide instantly then the vacuum drops as the carb is wide open and the engine is not sucking much. Sooooo, you have to in effect compensate for this small part it time by using an even greater supply of fuel if you want it to really jump in rpm. All of which can't be mitigated for steady state cruising. In other words they run constantly too rich from theoretical stoichiometric by quite a long way. And also why PD carbs offer something of a solution in adding fuel just for the acceleration phase and allowing more moderate cruising to be accomplished at something toward a normal fuel air ratio. In this sense they are simply better for the engine and a blueprint (a crude one) for modern fuel injection systems. In other words, asymmetric fueling based on engine load and response requirements.
Interestingly the CV carbs do something similar. I'm guessing again that Honda didn't want to use these for their first fours as they may not have been considered sporting enough / or offer the level of response the design team asked of their project. When you open the throttle on CV carbs, the butterfly controls demand from rider and in response the slide is raised via engine vacuum so aiming to avoid the transient vacuum loss you get on slides when you walk the throttle wide, aka Constant Vacuum. They also go further as I understand it in that the slides are usually damped going open so that when the engine vacuum s rising the slides lag behind this curve, this momentarily causes a higher vacuum peak just under the slide which pulls more fuel in to give a richer mixture just when needed and until the slide position catches up with engine vacuum. You could view the throttle butterfly as a request system that allows the engine cylinder vacuum to be allowed past and influence the slides which then accelerate the engine.
The CV types are useful as a comparison to the slide type carbs but also have relevance to the original question about the 450 CB.
So in realty on the fours, I think the oil is prematurely trashed by not being able to run a more optimal mixture. They are far more orientated toward race engine running than just cruising about.
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I'm to tiered too read this at the moment but from what I understand wasted fuel gets into the oil thus fecking it up.
I do wonder how long modern Diesel engines will last with DPF's.
If there stopped half way through there regen they dump the unburnt Diesel into the sump.
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But diesel IS oil, albeit of a very thin nature, check the V5 of a diesel vehicle, for fuel type it states "Heavy oil".
Sent from my X6pro using Tapatalk
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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.
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I love this and other threads like this,
the knowledge on this forum is wonderful
PLEASE carry on !!!
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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.
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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.
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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
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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.
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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.
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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.
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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 😀😀
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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)
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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 😀😀😀
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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.