Cosworth Cam Timing
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Cosworth Cam Timing
Ensure Cam sprockets are aligned.
Ensure Crank Pulley is aligned to the TDC Peg.
Ensure Auxilary Pulley Pointer is central to the Half Circle.
It all should like this.
Belt tensioner
Belt tension
Ensure Crank Pulley is aligned to the TDC Peg.
Ensure Auxilary Pulley Pointer is central to the Half Circle.
It all should like this.
Belt tensioner
Belt tension
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just to add, as a rule of thumb, in the longest run of belt.. there should be just enough tension in it to be able to twist the belt through roughly 90 degrees. as a final check wind the engine round twice on the bottom bulley with the plus out and check the alignment of all the above points again
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Don't you have to feed the belt round the pulleys anticlockwise too ? Starting at the crankshaft ?
Cosrush, these are superb pictures, about time we got something better than ford's low res diagrams
You might just have saved a few peeps some valves, etc...
Cosrush, these are superb pictures, about time we got something better than ford's low res diagrams
You might just have saved a few peeps some valves, etc...
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Originally Posted by frog
Don't you have to feed the belt round the pulleys anticlockwise too ? Starting at the crankshaft ?
Cosrush, these are superb pictures, about time we got something better than ford's low res diagrams
You might just have saved a few peeps some valves, etc...
Cosrush, these are superb pictures, about time we got something better than ford's low res diagrams
You might just have saved a few peeps some valves, etc...
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and if u notice , ever so slightly the left hand cam pulley is just out of plonk a smidgin - this is what justifies the need to vernier timing pulleys, if you are running a wild cam and it was out by that very small amount , you could end up with bent valves. on a std engine with std cams the EXACT mechanical timing is not quite so crutial.
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#8
Testing the future
i have a couple of points toadd, based on experience.
1) the crank pulley should be lined up so that the leading edge of the square peg is in line with the blade of the timing marker, rather than the centre of it as pictured (according to the YB service manual).
2) tensioner. the manual says to tension the belt by turning the tensioner clockwise and locking it. if you do this, the belt is trying to turn the tensioner anticlockwise which has a loosening action against the locknut. i had this happen that the locknut loosened and the cambelt loosened and jumped and fucked all 16 valves.
if you tension the belt by rotating the tensioner anti-clockwise, the belt pushes against it and keeps it tight against the locknut.
1) the crank pulley should be lined up so that the leading edge of the square peg is in line with the blade of the timing marker, rather than the centre of it as pictured (according to the YB service manual).
2) tensioner. the manual says to tension the belt by turning the tensioner clockwise and locking it. if you do this, the belt is trying to turn the tensioner anticlockwise which has a loosening action against the locknut. i had this happen that the locknut loosened and the cambelt loosened and jumped and fucked all 16 valves.
if you tension the belt by rotating the tensioner anti-clockwise, the belt pushes against it and keeps it tight against the locknut.
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Ive edited these pictures a little.
Hope this is an improvement, and clears up any ambiguity
***these have now been amended at the top of tis post***
Hope this is an improvement, and clears up any ambiguity
***these have now been amended at the top of tis post***
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Originally Posted by Stu @ M Developments
Couple of points to add:
1) Trailing edge is the correct TDC point.
2) The tensioner MUST be done clockwise to centralise the belt in the runners.
1) Trailing edge is the correct TDC point.
2) The tensioner MUST be done clockwise to centralise the belt in the runners.
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Would anyone mind if I add my two pence worth?
Don't assume that if the Aux Drive pulley is aligned as shown that the dizzy will be aligned correctly - Take the dizzy cap and shield off, put the rotor back on and align the centre of the rotor contact with the mark on the rim of the dizzy
Neil.
Don't assume that if the Aux Drive pulley is aligned as shown that the dizzy will be aligned correctly - Take the dizzy cap and shield off, put the rotor back on and align the centre of the rotor contact with the mark on the rim of the dizzy
Neil.
#17
Testing the future
Originally Posted by Stu
The tensioner MUST be done clockwise to centralise the belt in the runners.
i've got my tensioner done up anticlockwise, and the belt does not contact either the front cover or anywhere near the thermostat housing. but you've got me worried now. but i really don't want to change it as to me it's risky when it's clockwise and trying to undo it's locknut. i know that's how ford and cosworth say it should be done and that's how thousands are running.
CosRush, great pics. has clarified the crankshaft tooth position brilliantly as well.
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Originally Posted by foreigneRS
Originally Posted by Stu
The tensioner MUST be done clockwise to centralise the belt in the runners.
i've got my tensioner done up anticlockwise, and the belt does not contact either the front cover or anywhere near the thermostat housing. but you've got me worried now. but i really don't want to change it as to me it's risky when it's clockwise and trying to undo it's locknut. i know that's how ford and cosworth say it should be done and that's how thousands are running.
CosRush, great pics. has clarified the crankshaft tooth position brilliantly as well.
#20
Testing the future
Originally Posted by richm
mine is 4x4 if it makes a difference to the thermo housing..
#21
For anyone on verniers tha arent clear on where the pulleys should line up or might have been apart and put back wrong, the woodruff key is opposite the triangle, so starting point should be the two woodruff keys facing away from each other (ie the opposite way to the triangles, so facing apart not facing together)
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Originally Posted by chip-3door
For anyone on verniers tha arent clear on where the pulleys should line up or might have been apart and put back wrong, the woodruff key is opposite the triangle, so starting point should be the two woodruff keys facing away from each other (ie the opposite way to the triangles, so facing apart not facing together)
on kent verniers, the word 'cams' is in the position where the arrows would be,like this ( kinda hard to see sorry )
http://img.photobucket.com/albums/v2...s/IMG_3811.jpg
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