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Good morning.
I was wondering whether anyone has re-profiled their own cam followers, rather than sending to a machine shop.
If so, how did you go about it? I have some tools: a small lathe with vertical slide, a pillar drill, a Dremel and a vertical stand for it. On, and an a trusty power file, bench grinder and angle grinder............
Regards,
Jamie.
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Location: Auckland, NZ
29-06-2019, 11:01 AM
(This post was last modified: 29-06-2019, 08:44 PM by Bob Culver.)
I used an electric drill with wheel in it clamped to the toolpost. Doesnt have to be on horizontal centre but feed must stop 3/4 from centre.. Work out exactly where the centre corres 3/4 radius with minimum removal is and mark. Pack out from and clamp to faceplate. Arrange centre exactly on centre. Hand rock back and forth whilst advancing and traversing the drill. Finish on oilstone but beware as removes metal rapidly and easy to lose squareness etc.
It provides a more "full" lift and slightly extends opening. For a car not intended for racing revs the exh duration is already quite adequate and the valves large so probably only the inlets worth doing. The accelerations are much increased which is why it not done by Herbert.
With care and patience camshafts can also be home modified with similar basic gear.
Angle grinders are too fast for hard stones and the usual discs not intended for hard steel.
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While it is something to achieve regrinding your own,bear in mind they do need to be perfectly square and flat to the sides with 3/4-1" radius.
Is it worth it for £25 ?
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Hi Jamie, I made up a 'wet' grinder to do this job. As pointed out above if you can get them done for £25 or so it may not be worth your while unless you are like me and enjoy the challenge. I can take a picture of the one I made if any use? The bones of the grinder was an old tile cutter modified to take a grinding wheel that could be run wet. A jig was made to give the correct radius and allow adjustment to keep it square to the grinding wheel.
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29-06-2019, 08:47 PM
(This post was last modified: 29-06-2019, 08:54 PM by Bob Culver.)
Therer are many who acquire far more satisfaction from the challenge of restoration processes than mixing it in modern traffic in the end product. A lathe ensures squareness. I used another follower for packing.
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I realise that it would be fairly cheap to get the job done for me, but each "little" job that I can do myself saves money for the things which I cannot even attempt. I also enjoy the challenge.
Dave: I would be interested in seeing a picture of your device if possible.
Bob: that is a real help. Thank you.
Regards,
Jamie.
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I'll do most things - machining heads, valve seats, valves, making flywheels and even machining crankcases but despite having a decent workshop I wouldn't approach reprofiling followers in the spirit of Heath Robinson.
Accuracy, repeatability and surface finish are key to doing it right. These are very difficult to control for less than £25
Joined: Aug 2017 Posts: 2,748 Threads: 31
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The only crude part is the use of a drill with wobbly chuck but even a coarse wobbly grinding wheel sparked out will give an accurate fine finish. A few strokes on a very fine oilstone leaves a very fine finish. (I used to finish flat Javelin followers that way and they wrang together like toolmaker gauge blocks.)The radius is not critical. The relation of the centre to the sides is reasonably so but can be checked by rotating half a turn and checking the height of each flank from the lathe bed. It is the end result which matters, not the method.
(Toolmakers blocks are so flat that when placed together air is excluded and become hard to separate)
The method of regrinding camshaft does border on the Heath Robinson but it was notably effective until the crank folded it!
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I'm surprised that the name Paul Bonewell has yet to appear in this thread... He would be my go to man for such work - and get the cam done at the same time.. Might be more than you wish to fork out, but the results would be worth it..
hth...
