Author Topic: Camshaft longevity  (Read 501 times)

Offline Athame57

  • SOHC Master
  • Posts: 2101
    • View Profile
Re: Camshaft longevity
« Reply #15 on: November 04, 2026, 03:49:13 PM »
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!  :o
I brake for animals!
1978 CB400F2 named Elen.

Offline McCabe-Thiele (Ted)

  • Grogu
  • *
  • Posts: 8698
    • View Profile
Re: Camshaft longevity
« Reply #16 on: November 04, 2026, 04:28:27 PM »
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!  :o

A bargain at half the price?
https://www.abebooks.co.uk/9781844259946/Classic-Motorcycle-Race-Engines-Expert-1844259943/plp
Honda CB400NA Superdream (current money puddle)
Honda CB500 K1 (second money pit)
https://www.sohc.co.uk/index.php/topic,28541.0.html
Honda CB400 four super sport (first money pit)
Link to my full restoration http://www.sohc.co.uk/index.php/topic,23291.0.html
This is a neat 500 restoration in the USA.
http://forums.sohc4.net/index.php/topic,151576.msg1731556.html#msg1731556

Offline Mikep328

  • SOHC Pro
  • Posts: 541
    • View Profile
Re: Camshaft longevity
« Reply #17 on: November 04, 2026, 05:10:49 PM »
"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!!   :)
Mine:
1976 CB400F
1973 Norton 850 Commando
2015 BMW R9T
2017 BMW R1200RS
2021 Moto Guzzi V7 Special
Wife's:
2015 Ducati Diavel
2019 Honda Africa Twin
2019 Honda NCT750

Offline Skoti

  • SOHC Pro
  • Posts: 610
    • View Profile
Re: Camshaft longevity
« Reply #18 on: November 04, 2026, 06:51:30 PM »
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.


Skoti


Motorcycling is Life, anything B4 or after is just waiting...

1976 Honda CB750F1

Offline Athame57

  • SOHC Master
  • Posts: 2101
    • View Profile
Re: Camshaft longevity
« Reply #19 on: November 04, 2026, 07:08:07 PM »
"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!  ;D
I brake for animals!
1978 CB400F2 named Elen.

Offline K2-K6

  • Grogu
  • *
  • Posts: 6094
    • View Profile
Re: Camshaft longevity
« Reply #20 on: November 05, 2026, 10:24:37 AM »
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.

Offline K2-K6

  • Grogu
  • *
  • Posts: 6094
    • View Profile
Re: Camshaft longevity
« Reply #21 on: November 05, 2026, 10:35:47 AM »
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.

Offline Oddjob

  • SOHC Jedi
  • Posts: 4799
    • View Profile
Re: Camshaft longevity
« Reply #22 on: November 05, 2026, 03:55:34 PM »
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.
Kids in a the back seat cause accidents.
Accidents in the back seat cause kids.

Offline Athame57

  • SOHC Master
  • Posts: 2101
    • View Profile
Re: Camshaft longevity
« Reply #23 on: November 05, 2026, 06:20:48 PM »
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!   ;D
« Last Edit: November 05, 2026, 06:24:31 PM by Athame57 »
I brake for animals!
1978 CB400F2 named Elen.

Offline K2-K6

  • Grogu
  • *
  • Posts: 6094
    • View Profile
Re: Camshaft longevity
« Reply #24 on: November 05, 2026, 08:08:54 PM »
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.

 ;D ;D ;D

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.