Basic story this - if you ever watch a Marina B series engine when you rev it or turn it off, she jumps all over the engine bay. The reason is what BL designed originally to overcome the main motoring bugbear of the late 1960s and early 1970s - Noise Vibration & Harshness (NVH). Ford made the biggest fuss about it, particularly when they introduce the MK3 Cortina - a renowned rocker and roller. However all the other companies were trying to overcome the same problem and one of the key ideas was voided bushes - or to you and me - rubber bushes with holes in.
I had been thinking about what could be done and learned that when BL introduced the 1700 'O' series engine, they beefed up the engine bushes, because even they realised that they were too soft. I reasoned that as the 'O' series is based on the 'B' series (there a great article on this at www.austin-rover.co.uk) then I should be able to update/upgrade my 'B' series. If you have tried finding some 'O' series bushes you'll know that they are no longer listed and come up rarely on Ebay. However I went to Beaulieu Autojumble in 2006 and saw some on a stand, so I bought them. I managed to get a pair of used chassis side mounting brackets from Ben Clayton and trial fitted them. They were not Marina/Ital as the spacing was slightly wider and the threads were metric, however they did have some numbers on which I tracked down to Metro engine mounts. I decided to put the idea on the back burner and being one of life's hoarders, I hung onto them.
The following year I bought a genuine pair of 'O' series bushes and put them on the shelf. Finally whist the engine was out in Spring 2008, I got them all out to make some comparisons. The 'O' series and metro bushes could have come out of the same mould, however as I mentioned the pins are a little further apart, but nothing a round file wouldn't fix, also the threads are metric rather than imperial. The big difference is that the Metro bushes feel much denser/harder than the 'O' series ones, so maybe the guy on the autojumble stand did me a favour.
So with the engine half of the mounting brackets off the 'B' series and some measuring and drilling and filing I now have some firm engine bushes to fit shortly. Just the thing if I throw the car around a bit.
Shown below are (from left to right) the nearside 'B' series bush, a genuine 'O' series bush and a Metro bush, with the nuts and washers on.
More pics to follow.