Piper cam timing RST
04-01-2012, 05:03 PM
#1
Spanner monkey
Thread Starter
Piper cam timing RST
Anyone know the recommended cam timing on an Escort turbo using the Piper Bp 285t2 cam and Vernier?
I looked on the Piper website and can't see it anywhere!
Cheers
I looked on the Piper website and can't see it anywhere!
Cheers
04-01-2012, 05:56 PM
#3
No one can answer this question, it need setting on a RR so you can actually see the difference the adjustments make to your torque and bhp!
Second best is to do it this way...
Camshaft Timing
Determining True Crank TDC Position: Head off Block
Although the crank pulley will have a mark to show TDC position, this point may not be accurate due to manufacturing tolerances. It is always recommended to calculate the actual position of TDC rather than rely on the mark on the crank pulley. Fit the timing disc to the front of the crankshaft. A pointer for the timing disc can be made from a piece of bent wire secured under a suitable front cover bolt. Position a dial gauge to measure the travel of No 1 piston (see right). Turn the crank until the piston is at its maximum height and zero the gauge. You will find that there is a dwell period of approx. 10 degrees where the piston is at its maximum height. True TDC position is at the centre of this dwell period. To accurately measure the position of TDC, rotate the crankshaft and stop at a figure just before TDC, for example 0.020” on the dial gauge. Record the figure on the timing disc from the pointer. Now rotate the crankshaft and stop at the same figure (0.020”) after TDC. Record the figure on the timing disc again. True TDC is positioned in the middle of these two figures. The TDC position can be calculated by adding the two figures together and dividing by two. Adjust the timing disc so that it reads zero on the pointer at true TDC.
Determining True Crank TDC Position: Head on Block
If the head has not been removed when changing the cam, it is still possible to measure the true TDC position. The procedure is the same as before but the movement of the piston is recorded by using an extension resting on the piston crown (such as a socket extension or our special tool on page 114). Access to the piston crown is made through the spark plug hole.
Timing in the Camshaft
Rotate the crankshaft clockwise to 90 degrees after TDC. This will make sure all the pistons are half way down the bore. Now position the dial gauge so that it can read the lift of the inlet valve of number 1 cylinder from the top of the valve retainer (see left). Rotate the cam until the gauge shows that the valve is at full lift. As with the crankshaft, there will be a dwell period where the valve is at full lift. True full lift is at the centre of this dwell period. Roughly position the cam at true lift position. Now rotate the crankshaft clockwise to the full valve lift position (as specified on the camshaft data sheet - this figure is typically from 100 to 120 degrees after TDC), fit the timing belt or chain and set up the tensioner.
Second best is to do it this way...
Camshaft Timing
Determining True Crank TDC Position: Head off Block
Although the crank pulley will have a mark to show TDC position, this point may not be accurate due to manufacturing tolerances. It is always recommended to calculate the actual position of TDC rather than rely on the mark on the crank pulley. Fit the timing disc to the front of the crankshaft. A pointer for the timing disc can be made from a piece of bent wire secured under a suitable front cover bolt. Position a dial gauge to measure the travel of No 1 piston (see right). Turn the crank until the piston is at its maximum height and zero the gauge. You will find that there is a dwell period of approx. 10 degrees where the piston is at its maximum height. True TDC position is at the centre of this dwell period. To accurately measure the position of TDC, rotate the crankshaft and stop at a figure just before TDC, for example 0.020” on the dial gauge. Record the figure on the timing disc from the pointer. Now rotate the crankshaft and stop at the same figure (0.020”) after TDC. Record the figure on the timing disc again. True TDC is positioned in the middle of these two figures. The TDC position can be calculated by adding the two figures together and dividing by two. Adjust the timing disc so that it reads zero on the pointer at true TDC.
Determining True Crank TDC Position: Head on Block
If the head has not been removed when changing the cam, it is still possible to measure the true TDC position. The procedure is the same as before but the movement of the piston is recorded by using an extension resting on the piston crown (such as a socket extension or our special tool on page 114). Access to the piston crown is made through the spark plug hole.
Timing in the Camshaft
Rotate the crankshaft clockwise to 90 degrees after TDC. This will make sure all the pistons are half way down the bore. Now position the dial gauge so that it can read the lift of the inlet valve of number 1 cylinder from the top of the valve retainer (see left). Rotate the cam until the gauge shows that the valve is at full lift. As with the crankshaft, there will be a dwell period where the valve is at full lift. True full lift is at the centre of this dwell period. Roughly position the cam at true lift position. Now rotate the crankshaft clockwise to the full valve lift position (as specified on the camshaft data sheet - this figure is typically from 100 to 120 degrees after TDC), fit the timing belt or chain and set up the tensioner.
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