The thing that goes through my mind with this is the pulsating nature of the load imposed upon any bearing inside the camshaft. The total mass to be moved in the valve train for any one valve is about half a kilo. The maximum acceleration imposed by the cam profile is about 200 G. But the situation on the cam shaft is somewhat worse due to the lever nature of the cam follower which can increase the loading by a factor of about two. So at 6,000 rpm the cam end of the cam spindles can be subject to a fluctuating load of about 200 kg. Clearly needle rollers have been used so that they will stand this hammering for some time. As for longevity then it might be a case of "come back Oilite, all is forgiven". I would like to see a long term road test before I ceased to worry about the lifetime of needle rollers in this application.
E: Engine Cam Suppliers
- Thread starter Robert Watson
- Start date
I had a look at the 2004 invoices to see whether the cam bushings came from Kemps, the Spares Co. or Terry Prince.
Being a cheap SOB I priced stuff all over and got most of it from Terry Prince, left over from his RTV stuff. I emailed him recently to ask where the liners came from as they appear to be immune to wear.
It could be that the Honda chrome rings are a big part of that picture.
It turns out that the cam bushings did not come from any of the above suppliers. On John McDougall's bill there is a time amount for rebushing cams and refacing cams & followers plus a charge of $20 for bushing material.
John must have made the bushings from some stock he had, probably oilite.
He also liked to make replacement valve seats from a big chunk of austenitic iron that lived behind the lathe.
Glen
Being a cheap SOB I priced stuff all over and got most of it from Terry Prince, left over from his RTV stuff. I emailed him recently to ask where the liners came from as they appear to be immune to wear.
It could be that the Honda chrome rings are a big part of that picture.
It turns out that the cam bushings did not come from any of the above suppliers. On John McDougall's bill there is a time amount for rebushing cams and refacing cams & followers plus a charge of $20 for bushing material.
John must have made the bushings from some stock he had, probably oilite.
He also liked to make replacement valve seats from a big chunk of austenitic iron that lived behind the lathe.
Glen
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Do you know the previous history on those cams? As in who made them?
I never had the pleasure of meeting John, but understand he knew the importance of getting those followers to run true. Not just side to side alignment, but making sure the bore/pad wasn’t cockeyed.
No idea, the bike came from Australia.
The engine was supposed to have had a full Terry Prince rebuild with just 10,000 miles or so on but the elderly seller was a bit hazy on details.
It turned out that the top end was pretty tired but the bottom end had as new rod side wobble, so the cases were left together. The engine got a complete new top end, low expansion pistons, Honda chrome rings, Terry's liners, Kemps tuftrided valves, John's lead free gas type seats, guides, RD springs, Terry's long rocker bearings etc and had some work done in the timing chest as well.
They could be Terry's cams and followers, just not sure.
Before the elderly fellow had it another Ozzie, a young guy, had it as sole transport for ten years. It was his daily rider plus he crossed the continent on it several times on Holiday. It did a huge mileage in OZ.
Before that it ran around Scotland, before that England and before that , the Isle of Malta.
Poor thing has never had a rest in 72 years!
Glen
The engine was supposed to have had a full Terry Prince rebuild with just 10,000 miles or so on but the elderly seller was a bit hazy on details.
It turned out that the top end was pretty tired but the bottom end had as new rod side wobble, so the cases were left together. The engine got a complete new top end, low expansion pistons, Honda chrome rings, Terry's liners, Kemps tuftrided valves, John's lead free gas type seats, guides, RD springs, Terry's long rocker bearings etc and had some work done in the timing chest as well.
They could be Terry's cams and followers, just not sure.
Before the elderly fellow had it another Ozzie, a young guy, had it as sole transport for ten years. It was his daily rider plus he crossed the continent on it several times on Holiday. It did a huge mileage in OZ.
Before that it ran around Scotland, before that England and before that , the Isle of Malta.
Poor thing has never had a rest in 72 years!
Glen
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Just noticed this when I signed in this am.