Prop Balancing

[Old but not bold]

Hi,
Props on horizonally opposed motors need to be fitted near to right angle to the throw of the pistons. This is known as dynamic balance. I had a Cessna 170A for many years and a new Prop was fitted, it caused terrible vibration. Upon checking the Continental Manual it stated that the Prop had to be fitted with one blade at the 11 or 1 o'clock postion when the timing was at set at Top dead centre. After arguing with the Lame he altered it and it was smooth as silk.