Old Geezer

Hi Guys,

I tried this thread on the Cosworth general forum but did not get a response and wondered whether anybody here could give me some advice.
I have seen query on the forum previously about setting up the camshafts for belt replacement and difficulty with alignment of the pulleys in accordance with the manual. My 4 wd head has been skimmed, valves ground in and a new set of Burton hydraulic lifters fitted. The car has vernier type camshaft pulleys fitted which I have set the centre to simulate the original pulleys. The exhaust cam can be set so that the 'arrow' lines up with the top of the head casting no problem, although it tends to creep back. The inlet cam, however, springs past this point clockwise by a tooth or so and can only be aligned by turning it back with a wrench and holding it against quite considerable pressure. The turning moment past the Ford manual set point seems to be caused by the spring pressure of the opening of the valves on No. 3 cylinder as the camshaft lobes slip off the edge of the tappet and the cam cannot 'rest' at the correct set point. The situation occurs at every 90 degree turn of the camshaft whether the head is off or on the car, so it does not seem to be particular to any one pair of valves or cam lobes.
Previous comment on the general forum seems to say that the belt can be installed by holding the pulleys in the correctly aligned position with a wrench, but this does not seem to be right somehow and I am worried about getting the cam timing right.
Does anyone have experience of this problem and what causes it?
Any advice would be much appreciated

james kiely

iTrader: (5)

I thinks it's normal enough to have to get your inlet in position with a spanner so you can get the belt on. We'll that's what I did with mine

20/20 vision

it's not clear how you managed to set the pulleys accurately on the cams (and thus have any chance of accurately setting cam timing by reference to the pully's marks).

the proper way to set the timing is with the cam cover off and using dial gauges etc

do the pistons have pockets in them? what spec is the engine?

Old Geezer

Thanks for responses,

The car was rebuilt by GGR Racing over 20 years ago and has run like a dream since. It was uprated to 320 hp at that time and GGR have been kind enough to dig out all of the original set up info for me.
The vernier pulleys can really just be centralised to replicate the original pulleys with the arrows such that the centre line of the pulley is related to the keyway on the camshaft which at 180 degrees passes through the centre of the opposite tooth, if you see what i mean! ie the thing sits at 90 and 180 upright and horizontal.
GGR put some marks on the pulleys at the time which are now they say are invalidated by the head skim. They say set it up by the manual.
I take the point about setting up from scratch and Burton have a good description of how to do it. I have the necessary gauges but am probably being lazy in that it involves removing radiator/ intercooler to fit the angle chart on the crankshaft pulley. At the moment, I am trialing a dummy run using an old gasket bolted on to the block with plasicticine to see if there is any valve contact. I am thinking why should it be necessary to do anything other than follow the Ford manual procedure. GGR incidentally dont think there should be any spring resistance at TDC.
Sorry about Conundrum!