ET: Engine (Twin) CAM TO CAM WHEEL POSITION

kettlrj

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What is the position of the cam in the cam wheel such that the timing marks are in the right place relative to the cams. Mk1's & Mk3's. in a twin.
 

davidd

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Is this what you are looking for?

Factory Cam Positioning.GIF


David
 

Martyn Goodwin

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What is the position of the cam in the cam wheel such that the timing marks are in the right place relative to the cams. Mk1's & Mk3's. in a twin.
NEVER trust the timing marks when setting up the camshafts. Go back to first principles and use a timing disk. All explained by Phil Irving in "tuning for Speed" and also in OVR Edition 39.
 

kettlrj

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Thanks David, just what I needed to know that with the kit at my disposal, it will be a difficult job to do accurately.
 

timetraveller

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The job is much easier if you can get a helper to hold the points fixed while you are starting to tighten up the nut in the centre of the ATD. If you can find a helper then do the first few turns of the central nut by finger, so that not too much torque is available, and then, when it seems to be tightening down give a sharp blow on the ATD to try to make it stick on the taper. I generally find that the second or third attempt is about right as one learns what is moving and by how much.
 

timetraveller

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OOOPPPPSSSS!!!! That should have been in the thread about magneto timing. I have no idea what I did there. I'll go sit in the naughty/terminally confused corner.
 

davidd

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Richard,

There are two tools shown in this post:

https://www.vincentownersclub.co.uk/index.php?threads/twin-cam-timing-conundrum.9613/#post-90229

It is good if you can set the pins for the front and rear with cams that is already done, like a set of Robinson cams. It should take the guesswork out of the equation for you and Robinson's work seems to be a good standard.

If you can borrow a set of cams, even a "go/no go" gauge with a few locating pins for each cam would alert you to a misalignment. You to push the cam out and press it back in if it were off a bit.

David
 

A_HRD

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VOC Member
If you find they are not a very tight fit (one ton recommended), some people grind a short groove at the join between cam & pinion (on the other side of pinion from cam) then put a blob of weld on it. Finally grind the weld flat again.

Remember though, it might be YOU trying to part it again in the distant future! So don't overdo it!

Peter B
 

Nigel Spaxman

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Those instructions are very detailed. I don't understand them though. I have a tool I made for setting the wheels at the correct angle but it has a different setting for the front and the rear cams. I think it is amazing that the angle 159 degrees and 57 minutes is mentioned as I am sure that 160 degrees would be so close that once the cams were in the engine the 3 minutes difference would be very difficult to measure. Even the works settings that were recorded for Lightnings show that there are differences of a few degrees between each cylinder. The way I established the angles for my cams from a set of cams that a friend lent me, and even then it turned out that one of them was wrong, once installed in the engine and I had to re adjust it.
 
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