Their are now alternative additives that substitute for zinc, if there weren't engines all over the place would be self destructing in quantity. Flat tappets are only one wear issue, modern engines need very effective anti wear additives due to very high revs and loads on many components.
ET: Engine (Twin) Engine Oil
- Thread starter Doug
- Start date
The scar testing done by Jim Comstock showed what protection levels were in the oils tested, all of which were current offerings.
Some oils were abysmal, some offered decent protection and some were excellent.
Of interest , price paid was no indication of quality present.
Modern cars like my 07 Mazda 3 run about 50 lbs valve seat pressure with an overhead cam. Old flat tappet pushrod engines run at about twice that pressure. That's the reason better oil is needed in the old style engine.
If you happen to run a big cam on an old pushrod engine the over the nose spring pressure could easily be triple the highest seat pressure on a modern auto engine. You want some protection with that.
I use the Royal Purple HPS 20/50 in the 1360 as it has a very high lift cam, a TP MK5.
Glen
Glen
Some oils were abysmal, some offered decent protection and some were excellent.
Of interest , price paid was no indication of quality present.
Modern cars like my 07 Mazda 3 run about 50 lbs valve seat pressure with an overhead cam. Old flat tappet pushrod engines run at about twice that pressure. That's the reason better oil is needed in the old style engine.
If you happen to run a big cam on an old pushrod engine the over the nose spring pressure could easily be triple the highest seat pressure on a modern auto engine. You want some protection with that.
I use the Royal Purple HPS 20/50 in the 1360 as it has a very high lift cam, a TP MK5.
Glen
Glen
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Hard to give an exact figure on cam/follower wear........lubrication yes to some extent, but far from all.........mechanical issue........yes.....valve collar bottoming on lower guide, definately.........springs coil binding, ok possibly........poorly made parts or cams/followers made from similar materials........definate failure........i would say a huge amount of cam/follower failures are due more to poorly made parts than lubrication........Glen you were lucky with your Mk 5 cams, all the later ones were rubbish.........Stellite followers seem to be the best at lasting.......quality cams from Megacycle or similar last well.......even using ratio rockers and far more lift than 0.440 I'm running 530 lift and aiming for 600........But that will be with roller followers and cams to suit........
Stellited Mk2 cams and followers were fitted in 1980, been running Morris Golden Film sae 40 since then, no appreciable wear. My riding has slowed down a bit since then so I'm now thinking of going back to Mk3 cams. Any advice on good cam suppliers would be welcome as I was recently told of new cams which failed after low mileage. Cheers, Stu.
There were lots of posts relating to oil pumps and oiling system modifications so I have moved them to a thread of their own to make it easier to find the engine oil-related posts. (Link Below) (Ed)
Oil Pump and Oiling System Mods
Oil Pump and Oiling System Mods