Hi Everyone,
I am in the process of installing the Moss narrow belt conversion on my TR3A. I followed the Moss instructions and made a new TDC mark on the replacement crankshaft pulley in the kit using a piston stop. Before marking this permanently the Moss instructions go on to say that it's prudent at this stage to verify the cam timing by turning the engine so that valves No. 7 & 8 are "on the rock" and seeing if the TDC mark I have made on the pulley corresponds. Mine seemed to be a few degrees out so I looked at the Haynes Manual section on cam timing which suggested setting the tappet clearances to 0.040" (for this test only) on valves No, 7 & 8. I did this and used a dial indicator to establish the exact point at which No. 8 tappet stopped moving and No. 7 started to depress.
The end result is that my No. 7 & 8 valves are in the rocking position at 2 to 3 degrees BTDC on the crankshaft and not right on TDC as I assume they should be. Is this an acceptable error or should I be looking to get this right smack on TDC!!
One other thing. My ignition timing was set by trial & error last summer. I was experiencing a lot on pre-ignition so I continued to retard the timing until the pinking stopped. Earlier today I checked the ignition timing (before anything was disturbed with the narrow belt conversion) and noticed that it was reading only 2 degrees BTDC (easy with the rad and apron removed) and not 4 degrees as it should!! I was wondering if these two issues could be connected.
Anyone's advise on this would be greatly appreciated.
Regards, Neil.
I am in the process of installing the Moss narrow belt conversion on my TR3A. I followed the Moss instructions and made a new TDC mark on the replacement crankshaft pulley in the kit using a piston stop. Before marking this permanently the Moss instructions go on to say that it's prudent at this stage to verify the cam timing by turning the engine so that valves No. 7 & 8 are "on the rock" and seeing if the TDC mark I have made on the pulley corresponds. Mine seemed to be a few degrees out so I looked at the Haynes Manual section on cam timing which suggested setting the tappet clearances to 0.040" (for this test only) on valves No, 7 & 8. I did this and used a dial indicator to establish the exact point at which No. 8 tappet stopped moving and No. 7 started to depress.
The end result is that my No. 7 & 8 valves are in the rocking position at 2 to 3 degrees BTDC on the crankshaft and not right on TDC as I assume they should be. Is this an acceptable error or should I be looking to get this right smack on TDC!!
One other thing. My ignition timing was set by trial & error last summer. I was experiencing a lot on pre-ignition so I continued to retard the timing until the pinking stopped. Earlier today I checked the ignition timing (before anything was disturbed with the narrow belt conversion) and noticed that it was reading only 2 degrees BTDC (easy with the rad and apron removed) and not 4 degrees as it should!! I was wondering if these two issues could be connected.
Anyone's advise on this would be greatly appreciated.
Regards, Neil.