E: Engine More Adventures with the Comet
- Thread starter manxman
- Start date
Oilite bushes in this place, with dedicated oil supply into cam spindles??? That type of bushes is meant to be in places without real lubrication I´d think. So my guess when decent bronze bushes (phosphor bronze in your country? ) don´t seem to be suitable there must be a real problem with oil distribution in there. You´d have to think hard about reworking any oil grooves in there to supply all bushes plus to get all oil out onto cams and followers via holes in cams right at the start of lobes. Just drilling cam holes in fitted bushes will not do, some more grooves will be required, and you´d have to make sure oil will not be shut off when bushes may walk in cams. Do not hope for cam lubrication from the hole in the follower from any oil running down from the pushrods, not very positive as you can see in photos above, typically f***up Vincent cams and followers. It is mostly wishful thinking for some oil reaching there from flying pushrods, I´d imagine most oil from rocker supply will run down the pushrod shrouds, never getting onto followers. So I welded follower holes shut for keeping the oil wedge intact and improve oil supply via cam spindle routing instead.
Vic
Vic
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I think when Gary Robinson did the stelite cams and followers,
Which most people are very happy with, He welded the hole up in the followers.
Which most people are very happy with, He welded the hole up in the followers.
It certainly wasn't fitted with a Honda oil pump as my cams are well into their third 100k miles, the next Comet engine ("C") will have a plain floating bush B/E and the Honda pump feeding drectly into filter housing so all oil is fed into the timing cover with a seal around the quill so keeping as much pressure as possible as I want to see at leased a few p.s.i. at the cam rail,but with cylinder supply blanked off. The "A" Comet that my mate Bill has just assembled is fitted with a plain floating B/E bush, with the supply oil pump increased by half as much again by increasing the width of the gear wheels by 1/16" from 1/8" so now 3/16". Mr Vincent mentions in his autobiography that he wished he had kept his original pump design as it was certainly superior with more and a constant flow to the intermitant post war design.
bananaman.
bananaman.
In the 60s/70s the cams were made of Cheese !,
Along with some car ones 70s/80s.
My first Twin Outfit would not go over 70 mph, But quick up to that, After a lot of playing,
One day I was doing the tappets and found the Valves were hardly opening !!,
Amazed it ran at all .
After that it was off the road for 3 years and turned Blue !,
That's why I say if it runs leave it alone, Can't afford to be off the road for another 3 years.
Along with some car ones 70s/80s.
My first Twin Outfit would not go over 70 mph, But quick up to that, After a lot of playing,
One day I was doing the tappets and found the Valves were hardly opening !!,
Amazed it ran at all .
After that it was off the road for 3 years and turned Blue !,
That's why I say if it runs leave it alone, Can't afford to be off the road for another 3 years.
The cams and followers are from my 1952 Rapide. I have good reason to believe that the indicated mileage of 32,000 is genuine. Also It appears to have only covered 1100 miles since 1982. It’s new to me so I’m relying on several old MOT certificates. My assumption is that the original case hardening was faulty and/or the lubrication system at some point.
The oil filter was very dirty/blocked but amazingly the bike ran pretty well. It certainly goes better now with new parts fitted though!
The oil filter was very dirty/blocked but amazingly the bike ran pretty well. It certainly goes better now with new parts fitted though!
When I purchased my Rapide in 1965 the cams and followers were very similar to Bellboy's, if anything a little worse if that is at all possible, so bad in fact that one of the previous owners had ground away a fair portion off the top of threaded bulb on the rocker arm to enable enough adjustment to compensate for the wear, so how did it run in that state you may well ask, the answer is surprisingly well, especially when all the other extreme wear within the engine was taken into account, and the Amal Type 276 carb slides rattling around like the proverbial...... incredible really.
There was a lot of stories like this years ago,
But the tappets are set on the base of the Cam !!,
Which doesn't wear, So any adjustment problem was something else ??,
When My Blue Bike was finished 1970, I had fitted Mk2 cams, They were also made of Cheese !,
For a lot of us the only way forward was Gary Robinson, I think He has now stopped ??,
But I had a set ready for my new Comet a few years ago, But the Bike is Not yet finished.
Sorry, Just thought, The wear on the follower Would give that problem.
But the tappets are set on the base of the Cam !!,
Which doesn't wear, So any adjustment problem was something else ??,
When My Blue Bike was finished 1970, I had fitted Mk2 cams, They were also made of Cheese !,
For a lot of us the only way forward was Gary Robinson, I think He has now stopped ??,
But I had a set ready for my new Comet a few years ago, But the Bike is Not yet finished.
Sorry, Just thought, The wear on the follower Would give that problem.
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