Setting 1500 engine valve timing

[mpbarrett]

I am starting to rebuild my rebored engine for my Herald. its got a new camshaft to go in  and new drive gears and chain.
I have realised that I  don't know how to setup the timing/position of the drive chain to the camshaft!

I can rotate the crank round until its at TDC but I am unsure what the valve position should be at the point. At the moment the engine in on the bench and it doesn't have a head on it but I can measure the cam shaft lift by using a dial gauge onto the cam followers (by using the push rod and  centralizing it in the block).

There must be an easy way of doing this. Will have a Google but all suggestions welcome!

cheers

mike

 

 

[mpbarrett]

ok so a quick bit of Goggling brought up a post on a USA Spitfire site by John Davis.

"Then, use "Equal lift on overlap".
This refers to the four stroke cycle. At the end of the exhaust stroke, the inlet valve starts to open before the exhaust valve is fully closed, so that at a certain point, they are both open and lifted by the same amount.
This point should be at TDC!
So set the crank to TDC, and then rotate the camshaft until the inlet and exhaust valves are equally lifted.
Then install the cam sprocket and chain.
Your cam is correctly timed!
Do this on No.4 (or 6) cylinder and then you know that No.1 is timed for the ignition stroke.
It's easiest to do with two dial gauges and stands. but they aren't very expensive these days.
This method works with any camshaft that is 'symmetrical', with cams that move up and down the same way and are evenly positioned on the shaft.
Good luck!
John"

As the new cam is symmetrical I will give this a go.
Mike

 

[Pete Lewis]

the other way to get the cam lobes tdc  is blue tack a card disc on the cam , turn to get max lift on the lobe  turn a to get the dti to drop say 0.05

mark disc turn other way to the same drop and make disc   the tdc of the lobe is halfway between the two marks

john also loves a piston stop , which  simply blocks the piston rise near the top , protractor disc on the crank  mark clockwise to the stop and anti clock to the stop  half the marks and there  is  crank tdc  without trial fitting the timing cover 

the cam sprocket hole sets give 1/4 tooth increments  depending which pair you use

Pete

[Anglefire]

I drew a cam timing disk so I could stick it to the pulley - link to the thread is here