Timing Marks on Engine Pulley

[willcolumbine]

I fitted a new alloy pulley to my car a few months back. Unfortunately now I'm in the situation where, having fitted simonbbc electronic ignition, I need to reset my timing. I've got no timing marks to work from on the crank pulley and it's making my life difficult!

Looking at the crank design it seems that when the first piston is at TDC the woodruff key will be at the top. Could I just take the pulley off and use the position of the woodruff key groove to mark the pulley? Would that work?

[GT6 M]

Will,  still got the old pully, !!!   put em side be side, and just copy the marks across frae one till the other,

or are the keyways different,
if so, just move about till you think its near,.

marcus

[James]

Yup, you're right Will.

While you're at it mark up 0, 10, 20, 30 degrees - very handy - maybe even in 5 degrees increments

It's easy enough to work out with a bit of pi the distance of 10 degrees - or copy it off as Marcus says

[willcolumbine]

796 wrote:

Will,  still got the old pully, !!!   put em side be side, and just copy the marks across frae one till the other,

or are the keyways different,
if so, just move about till you think its near,.

marcus

Sadly the old pulley is on it's way to its new owner in Belgium so that isn't an option!

[GT6 M]

have you got an old six cyl one about, cos they marked up to 30 degs ..either side..

on these, 2 degs = 1/8hinch, ish,   so you can doo it with a rule,

just  find tdc, and then mark of from there, best done on the bench

some one you no, no got a pully handy,thats near,!!!!

[willcolumbine]

jcarruthers wrote:

Yup, you're right Will.

While you're at it mark up 0, 10, 20, 30 degrees - very handy - maybe even in 5 degrees increments

It's easy enough to work out with a bit of pi the distance of 10 degrees - or copy it off as Marcus says

Cool! That's nice and easy then!  :)

[James]

I am still not sure I would trust it 100% though! I guess if you can derive the position accurately then it's ok

[Pete Lewis]

there's a tdc marker on the flywheel and engine back plate,, sorry not very useful unless the engines out  

if you want to be close you could devise a piston stop down a plug hole, turn engine to touch in both directions and then half the marks ,  but thats a bit of a drag,

as its best to set on the road to get best clocked acceleration without pinking , you dont realy need the marks, to be that accurate as you are unlikely to be using factory settings with the low octane
fuel, best we get is 97ron  design was for 100/101   and 95ron went in sidevalves and lawnmowers
so do you really need them ???

Pete

[JohnD]

A way of checking your Woodruff key method is to use "equal-overlap" in reverse.

All Triumph camshafts are 'symmetrical', so that on the up-stroke between two four-stroke Otto cycles (suck-compress- ignite exhaust), the 'overlap' between exhaust and suck, the exhaust and inlet valves should be equally lifted at TDC.

So turn crank until that is so, on the valves to bores one or six, or in your case one or four.  That should be TDC.
A dial gauge is useful.

JOhn