Timing the Rootes Competitions R20 camshaft

Rootes Competitions Department  made some great Hillman Imp camshafts,among them the R17 the R20 and the R23,each has its own setting for the number one inlet valve at the engines TDC ( top dead center) this is not hard to acheive if you read the A4 installation papers supplied by Rootes at the time.

The tool you will need is a dial gauge in imperial,thats Inches,well parts of 1000s of them,yes that price is correct,I thought it cheap myself when I bought it in about 1971.

The back mount plate was an alloy,it fell apart with age,we all do this? anyway I made a new one and used a Hillman Imp lock tab plate as the method of mounting the dial gauge,just as I did back in the early seventies.

The multihole competition camshaft sprocket,check the ring of holes near the center.

The lock tab is then mounted on the cylinder head,I use the nearest stud,its close to the number one inlet valve tappet.With the camshaft removed,from TDC,take the engine backwards so that the number one piston is about 1"down the bore.Replace the camshaft,rotate it untill the number one valve is open to 113 thousands of an inch on the dial gauge.To do this,set the gauge up to read 113 thous,on the surface of the number one valve tappet face,then rotate the camshaft clockwise,when it reads zero,stop.When this is done turn the engine back clockwise  and the when  TDC engine pointer is in line stop.Then fit the drive chain over the  the drive sprocket to the nearest available drive peg hole,use a new lock tab and torque to 20 pounds,then lock the bolt with the lock tab.

With the spark plugs removed to reduced compression,slowly turn the engine by hand clockwise to ensure the timing is correct and no valves are hitting pistons etc.I always re test the timing at least once more,its quite simple when your up to speed with the method and so important to get this job right.

Note you will need the Rootes Competitions multihole camshaft sprocket to do this job.

TDC,you MUST have the correct pointer plate.

Note the three camshafts have different settings!

How hard can this be?

R McB