Camshaft longevity

[Athame57]

I can also recommend the book 'Classic Motorcycle Race Engines' by Kevin Cameron as a good read for anyone into engine technology.

I just went looking for that Dave, but the price tag is super charged, I havn't got enough interest to spend about £260.oo for a second hand one! 

[McCabe-Thiele (Ted)]

I can also recommend the book 'Classic Motorcycle Race Engines' by Kevin Cameron as a good read for anyone into engine technology.

I just went looking for that Dave, but the price tag is super charged, I havn't got enough interest to spend about £260.oo for a second hand one! 

A bargain at half the price?
https://www.abebooks.co.uk/9781844259946/Classic-Motorcycle-Race-Engines-Expert-1844259943/plp

[Mikep328]

"Fullers Earth"...wondered what that was when I read the Sherlock Homes story, "The Adventure of the Engineers Thumb"!  Looked it up back then but have to look it up again because I forgot!!   

[Skoti]

My own experience....

My hack 400/4  was acquired in 1994 with just 11,500 miles showing, since when it has seen  22 years commuting 52 weeks a year followed by 10 years of use on nice days in the winter and has  this last week just had its 127,000 mile service .

EVERY major engine component is as fitted by the factory, including crank / shells, barrels / pistons and rings (barrels NEVER removed), cylinder head/cam/rockers/valves.
It has had a couple of head-gaskets, and one cam chain and primary chain (96,000 miles now since they were fitted). Also has been serviced to the letter of Honda's prescribed schedule - oil every 1500 miles, filter every 3000 miles, etc....

Does not smoke / burn oil / rattle, or give any indications of the need for mechanical work.

My conclusion would be that these things are basically just "right", and as long as they are serviced as Honda suggest are fairly un-breakable - as also suggested by the analysis by K2-K6 particularly in respect of oil condition/ quality and tappet clearances

My experience is similar and I must agree with your conclusion.

Too many people here worry too much about too little.


Better to get out and enjoy riding a classic Honda before age or health overtakes that possibility.

[Athame57]

"Fullers Earth"...wondered what that was when I read the Sherlock Homes story, "The Adventure of the Engineers Thumb"!  Looked it up back then but have to look it up again because I forgot!!   

It sounds like a TV program to me! 

[K2-K6]

Excellent analysis by both K2-k6 and Honda-san. I always change my oil and filter at the same time but maybe I should now reconsider?

Nigel, in view of your replies on this particular thread and others in the past I think you should fess up and admit your are in fact, an engine designer for Honda Moto GP . I can also recommend the book 'Classic Motorcycle Race Engines' by Kevin Cameron as a good read for anyone into engine technology.

Thanks Dave, but I know if I were to visit their R&D of HRC, I'd find far more about what I don't know than I understand now  wouldn't that be an interesting factory visit though ?  Pretty cool to be shown around such a facility.

I've put before how much benefit I got from my apprenticeship years, so much detail and clever people to learn from. Fabulous foundation from which to understand technical field generally.  We've got a reunion this weekend of our year's intake to meet and yak about it.

I like Kevin Cameron's writing. I bought editions of Cycle and cycle world (he involved in both) when much younger in tbe 70's. There was a newsagent that stocked them near to my Nan's place close to Heathrow which I could go to when I stayed with her and my grandad.

[K2-K6]

Interesting idea about the coating of a new oil filter by fine sized particles being better at filtering through the interstitail spaces left as it it builds up during the filtering process.

Many years ago when working in a chemical plant in Germany you could extend the life cycle of candle filters used in the filtered flow process by coating them first with Sawdust to prolong the flow rate without too much change in the pressure needed to maintain a given flow rate, Fullers Earth was even better than Sawdust, it almost doubled the time between back flow cleaning  from every two hours, to every four hours whilst still maintaing the main flow rate.

My experience showed the same Ted. Was working on filtration in chemical domain in which we were testing various filters, of which a manufacturer could build in various rates of specification.  Lowest was @ 1 micron nonminal for system that we routinely ran 10 micron, ultimately to strip out some of the chemical components (too far in other words) at which level the flow rate decreases rapidly.  Reverse osmosis system to evaluate for component recovery in stripping that out of water etc another evaluation of ultimate performance too with semi permeable membrane.

Certainly illuminating in depth consideration of what's possible, too far, effectiveness and coming to specification that's best balanced for task assigned to it.

[Oddjob]

I’m beginning to think English isn’t your first language Nige as I didn’t understand most of that reply to Ted.
Try and keep replies to big hammer, hit. My level.

[Athame57]

I’m beginning to think English isn’t your first language Nige as I didn’t understand most of that reply to Ted.
Try and keep replies to big hammer, hit. My level.

Thanks for this mate, I was starting to wonder if I'm even less educated than I thought, or just intellectually challenged!  

[K2-K6]

I’m beginning to think English isn’t your first language Nige as I didn’t understand most of that reply to Ted.
Try and keep replies to big hammer, hit. My level.

 

Yes I have to parle la lingo working in a different industry  tell you what, it's easier doing motors and carbs than some of the things there. 

[K2-K6]

More thoughts on this generally.

Clearly the filter is important in running engines, but not ultimately preventative in it's function.

Often missed, the filter is secondary in line of defence because it only catches that which the oil has failed to protect. Any wear that's initiated from oil failure, the filter has no part in, just stopping that material going around the system again. But, it's already dropped down to sump, passed through pickup strainer, smulched through oil pump rotors, then caught in the filter material for us to see.

Characteristic of cases like Honda San 400 four, if taken apart is that virtually all of the original material is still in place and where it should be. And why oil specification, condition in service etc are do fundamental to long component life.
The largest influence in regard to oil condition I've experienced has usually been dilution with fuel to effectively break down oil film performance. Ultimately, this is how/why manufacturers set oil change intervals, if done honestly. 

Fundamental to this in these older type engine is not metallurgy or other influence. It's slide carburettor WITHOUT acceleration enrichment equipment, meaning they have to continually run in slight excess to give reasonable response to throttle input against torque requirements.   Put simply, its part of tge practical limitation in running them.  CV type (and accelerator pump equipped carburettor) properly optimised, are designs seeking to avoid this.

[Skoti]

More thoughts on this generally.

Clearly the filter is important in running engines, but not ultimately preventative in it's function.

Often missed, the filter is secondary in line of defence because it only catches that which the oil has failed to protect. Any wear that's initiated from oil failure, the filter has no part in, just stopping that material going around the system again. But, it's already dropped down to sump, passed through pickup strainer, smulched through oil pump rotors, then caught in the filter material for us to see.

Characteristic of cases like Honda San 400 four, if taken apart is that virtually all of the original material is still in place and where it should be. And why oil specification, condition in service etc are do fundamental to long component life.
The largest influence in regard to oil condition I've experienced has usually been dilution with fuel to effectively break down oil film performance. Ultimately, this is how/why manufacturers set oil change intervals, if done honestly. 

Fundamental to this in these older type engine is not metallurgy or other influence. It's slide carburettor WITHOUT acceleration enrichment equipment, meaning they have to continually run in slight excess to give reasonable response to throttle input against torque requirements.   Put simply, its part of tge practical limitation in running them.  CV type (and accelerator pump equipped carburettor) properly optimised, are designs seeking to avoid this.

Yes, good post and much to agree with.



May I also suggest that during short trips where damaging condensation build up in the engine oil doesn't get enough heat to properly dry off, or over rich mixture due to knackered needle jets which dilute the oil also cause premature engine wear.


I'm on 1,500 mile oil change intervals and minimum ride outs of 50 miles or more.

Done over 40,000 miles in the last 10 years and on 63,000 miles now, all main engine stuff original.
PO owner bought the bike in 1977 when 1 year old so maintenance history known.