Morning Robert- would you clarify what you mean by setting the valves at equal lift please.
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ET: Engine (Twin) Half Time Pinion (Punch Dot Marks not present)
- Thread starter Phil Arundel
- Start date
Morning Robert- would you clarify what you mean by setting the valves at equal lift please.
Digital dial gauges are far far easier to use than the old mechanical type trying to count the graduation of little & large hands either going up or coming down. Fitted on top of valves or on a bracket secured about the rocker feed bolt and taking movement from the tappet, set to zero when on base circle and when they read the same they are, clamp the cam with nice large fat washer with timing cover screw, remove half time pinion as you have been using it to turn engine & cam , set engine at 4 degrees BTDC, although the chain driven Trials Iron done by the works in 1952 was set equal lift at TDC spot on,as Vibrac will confirm as we checked it several times. Four degrees is not much in the real world any way, less spitting back through the carb !
bananaman .
bananaman .
Thats the way to do it Marcus! build it backwards, clever people call it counterintuitive last thng is to slip the half time pinion on the locked engine and turn it to the best keyway fit
Look here
https://www.vincentownersclub.co.uk/index.php?threads/mk3-cams-timing-figures.9878/#post-92586
at post #6.
As the exh closes the intake is opening, On this engine with Mk1 cams the exh was .075 lift closing when the intake was .075 when opening, hence equal lift. I should have said there that I have a set of very light springs I use for this setup so the force of the valves opening and closing trying to turn the engine over is virtually nothing and it all stays where you put it. When all is said and done I change out the springs for the proper ones.
https://www.vincentownersclub.co.uk/index.php?threads/mk3-cams-timing-figures.9878/#post-92586
at post #6.
As the exh closes the intake is opening, On this engine with Mk1 cams the exh was .075 lift closing when the intake was .075 when opening, hence equal lift. I should have said there that I have a set of very light springs I use for this setup so the force of the valves opening and closing trying to turn the engine over is virtually nothing and it all stays where you put it. When all is said and done I change out the springs for the proper ones.
Light springs was the first bodge I used to help setting up equal lift then I realised there was an easier way.
I made up a set of extra long pushrods; remove the 'tappet' adjusters and the proper pushrods and put in the extra long pushrods then dial gauge on the end of each of the extra long pushrods and now work on equal lift measured in the cups of the cam followers. Simple
A word of advice as to marking gears with punch marks.........Because they are hardened, if you mark the tooth with a punch mark you will almost certainly fracture the tooth, this can break off and cause damage if it gets trapped between rotating gears. You are better off using a dremel with a thin cut-off disc and marking the tooth that way.
Why even bother with punch marks - unless it was you who put them there you cannot trust them anyway.
What I do when I an dismantling an engine is use multiple colours of nail polish to mark the mating positions of each of the gears (different colour for each gear mating) in the timing case then its easy to reassemble in correct relative positions.
Once reassembled then use a cloth and acetone (nail polish remover) to remove the marks you put there so next time you wont get confused.
Martyn
Like this
I hate to question Greg's expertise but I don't think that the cam wheels are surface hardened. My understanding is that they are a pre-hardened EN24 that is tough all the way through. I have never seen one which shows signs of flaking etc.