cam timing

[dhla40]

Is it possible to adjust non vernier cams and if so how is this acheived?  My manual only shows the procedure for vernier cams.  My intake cam timing looks to be late by about 8 degrees, is this worth mucking about with?

Sean

[Richard Fridd]

if only one camshaft is late perhaps it is wrongly set by an amount which represents one tooth of the timing chain.if both are incorrect perhaps the wrong timing mark on the flywheel has been used for the valve timing.as far as i know there is no fine adjustment without verniercams.if you do change to these i think you need to use early s2 vernier wheels to suit your chain.richard

[dhla40]

Judging by eye one tooth seems to equate to 10 degrees on the flywheel so I might jump it forward, any idea how far the cam can be advanced before valves start hitting pistons

Sean

[Neil Lewis]

Be very careful because even if you can't discern any valve to piston contact while turning the engine over by had, once started the pistons will come up higher and the valves down lower due to stretch of con rods etc.  So, if your valves were JUST missing the pistons by hand, you might hear teh ineitable tapping once the engine is running.

It is possible to time the later engines using teh earlier multi-hole sprockets.  It took me several hours of frustration in my shed but eventually I got it spot on.  Because the peg is fixed in the cams you have to split the chain and, while holding the cams in one place, move the sprockets around one hole at a time.  Reconnect the chain and check the valve timing and keep doing that until you get as close as you can get.  Mark the holes in the sprockets (I think there are thirteen) and make copious notes as you go so, when you get back to the first hole, you can choose which was the best hole to use.  Tedious in the extreme but it does work!!!

If you can't find multi-hole sprockets it is possible to drill your own holes if you have access to a fancy machine tool drill which can be moved around the correct amount of degrees for each hole.  A machine shop should be able to do that for you, but they may not want to!

Neil