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Long story short, SR head gasket job was done by a shop to a friend's customer's motor. job was botched and can ran like crap. only thing done was a HG so i suspected mechanical timing was off.
we pull the valve cover and see the cam timing marks are between links on the chain, aka half a link off compared to the factory. the oil pump wasn't touched so we are pretty sure the crank sprocket should be on a link, not in between. the number of rollers in between the marks is correct (20). We move the chain to what we think is the right direction, but it's always hard to view it (aka 10'oclock vs. 10:05 for example) without being able to count links down to the crank sprocket. so few questions here:
1) why does the ESSAR not have a reference mark between the 2 cam sprockets or an extra reference mark up top on the block?
2) can the timing chain move from the crank sprocket when the oil pump is on? we checked a spare oil pump and saw there are dowels which prevent the chain from dropping when the cams are removed, so it leads me to think the chain can't jump timing at the bottom unless you pull the pump.
So we guessed at the mechanical timing to the approximate pictured locations in the FSM, but all we know for a fact what's correct is the 20 rollers between the cam gear marks, not any of the roller lengths going down to the hidden crank sprocket. fire up the car and in order to set the ignition timing light to match the power fc's live ignition timing readout, we need to advance the CAS all the way. this tells me mechanical timing is still off, and we need to move the chain again - but which way?
3) which way do i need to rotate the cam sprockets? my guess is both gears should be moved one full link CCW.
we pull the valve cover and see the cam timing marks are between links on the chain, aka half a link off compared to the factory. the oil pump wasn't touched so we are pretty sure the crank sprocket should be on a link, not in between. the number of rollers in between the marks is correct (20). We move the chain to what we think is the right direction, but it's always hard to view it (aka 10'oclock vs. 10:05 for example) without being able to count links down to the crank sprocket. so few questions here:
1) why does the ESSAR not have a reference mark between the 2 cam sprockets or an extra reference mark up top on the block?
2) can the timing chain move from the crank sprocket when the oil pump is on? we checked a spare oil pump and saw there are dowels which prevent the chain from dropping when the cams are removed, so it leads me to think the chain can't jump timing at the bottom unless you pull the pump.
So we guessed at the mechanical timing to the approximate pictured locations in the FSM, but all we know for a fact what's correct is the 20 rollers between the cam gear marks, not any of the roller lengths going down to the hidden crank sprocket. fire up the car and in order to set the ignition timing light to match the power fc's live ignition timing readout, we need to advance the CAS all the way. this tells me mechanical timing is still off, and we need to move the chain again - but which way?
3) which way do i need to rotate the cam sprockets? my guess is both gears should be moved one full link CCW.
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