Matchless twins used followers like those shown. Earlier engines used a shorter version to the later engines. Can't remember the change over year.Those pivoting (unfortunately leading link) lifters in your second photo (post #13) would definitely be lighter, in effect, than the BSA/Triumph ones - even though they are lighter than the STD Norton ones. JS mod is based on these, no?
Most of that Domiracer mod in that photo is a doddle, except the lifters. I'll have a look around at Jap finger lifters from the '80's - maybe some promise there?
Just need them to be short enough to expose the reverse rotating cam to the dribble of oil from above.
Will also need substantially longer pushrods - probably about 2" longer. The pushrods will have to pass through the dams I mentioned in post #16.
More & more interestinger
Cheers
Oh - I haven't seen those - will have to investigate.Matchless twins used followers like those shown. Earlier engines used a shorter version to the later engines. Can't remember the change over year.
The Domiracer cams/followers were lubricated by a pressure feed through the camshaft centre to oilways in the lobes, just like the Dunstall race cams.As a slight side-line - it appears that some type of dam is required in the lifter tunnels to regulate and direct oil onto the critical cam/follower interface. Not shown in that photo (that I can see)
Cheers
Seems the finger lifter would effectively also change the profile, as the lobe would hit and drop the lifter earlier or later (depending on trailing or leading pivot) than a lifter that moves vertically, sharkfinning the cam lobe. Might be an expensive can of worms. Note the pic of the barrels with the finger lifters looks like it hasn't been on a bike but tucked away in a box for a while.Another (weird?) thought is that you could use the finger lifters as a "cam-amplifier" by changing the position of the pushrod-ball socket.
Move the socket forward and increase valve lift for the same cam (and vice versa!)
As I said - interestinger!
Cheers
It would be relatively easy to plot differences in valve lift between the OEM and pivoting lifters. The vertical position of the shaft would have a substantial influence.Seems the finger lifter would effectively also change the profile, as the lobe would hit and drop the lifter earlier or later (depending on trailing or leading pivot) than a lifter that moves vertically, sharkfinning the cam lobe. Might be an expensive can of worms. Note the pic of the barrels with the finger lifters looks like it hasn't been on a bike but tucked away in a box for a while.
@Madnorton, a reprint of that poster would be something I'd buy. Don't know if your ownership includes rights to that or not.
Yea. I think a simple CAD program could help figure it out, but getting a one-off cam ground isn't cheap. I'm of course adding my own financial willingness, not yours, to your project, which, admittedly, is a silly thing to do.It would be relatively easy to plot differences in valve lift between the OEM and pivoting lifters. The vertical position of the shaft would have a substantial influence.
I have contacted British Only in Austria for dimensions - they sell new ones of theseOh - I haven't seen those - will have to investigate.
Probable means AJS twins had the same.
Thanks
Thanks - I didn't know that.The Domiracer cams/followers were lubricated by a pressure feed through the camshaft centre to oilways in the lobes, just like the Dunstall race cams.
Yes, the poster thing is something we plan to look at we have many general assembly drawings which would make great posters. We even have the Cosworth engine drawings, some of which are related to the ill fated embarrassment that failed and many of an unit twin 8V engine which they should have built.Seems the finger lifter would effectively also change the profile, as the lobe would hit and drop the lifter earlier or later (depending on trailing or leading pivot) than a lifter that moves vertically, sharkfinning the cam lobe. Might be an expensive can of worms. Note the pic of the barrels with the finger lifters looks like it hasn't been on a bike but tucked away in a box for a while.
@Madnorton, a reprint of that poster would be something I'd buy. Don't know if your ownership includes rights to that or not.
As did the lightweight range (G2/G5), Velocette Vpiper/Venom and, as noted, Norton M50/ES2.Matchless twins used followers like those shown. Earlier engines used a shorter version to the later engines. Can't remember the change over year.
I believe JS follower blocks were designed with oriented dripping onto the camshaft in mind. Forget O-rings - pushrods make an angular motion in addition the the vertical motion, so they won't work.I think I would make a couple of dams (holes for pushrods + o-rings on pushrods?) sloped downwards towards the front and hole(s) at the front (maybe with shaped "drippers" to direct oil onto the cams as per OEM.
I see Andover are offering these for (ouch) 1000GBP - https://andover-norton.co.uk/en/sho...-under-68mm-requires-honing-to-finished-size-
Is that barrel Nikasil or steel sleeve?Some 15 years ago, I bought an alloy 850 barrel from Norvil ( Les Emmery) for my Commando.
It has been excellent, except :
1. At the 1st retorque, I pulled the helicoils.
Called Les, and he fell out of the sky ( of course..). I made bronze inserts instead.
2. At 40 000 km after the rebuild, I had to replace a worn camshaft, and found a broken top piston ring.
3. Two years ago, at 80 000 km, I lost compression and found both top rings broken.
The cylinder bores looked perfect, so I just re-ringed after a light hone.
The cam followers were resurfaced when the cam was changed and looked fine, so I didn't inspect the pushrod tunnels.
Oil consumption has always been negligible.
Lately I tend to prefer my N15 over my Commando for travelling.
It used to be 50/50, but now it is more like 80/20.
So in all, The alloy barrels are holding up very well, except for the broken rings.
I know a too small ring gap can cause broken rings, but I don't think that is/was the case.
Many 100 000 kms on Nortons, but I can't recall any broken rings in iron barrels.
Could there be a link between alloy barrels and broken rings?
Seems odd, but it worries me a little.
Head bolts:
Steel sleeve.Is that barrel Nikasil or steel sleeve?
Cheers