SU Carb

Post by **rio678** » Sat Apr 12, 2008 10:36 pm

Hello again everyone, Little bit confused here, i am trying to order a new pancake type filter for the morris as it has had a SU carb upgrade and i am greeted with different sizes, how can i tell what mine is? not sure where to look.

Post by **bmcecosse** » Sun Apr 13, 2008 8:52 am

If you think it has a larger carb fitted - then simply stick a steel rule across the inlet and report back. Once you know the size - then you can order a filter. beware - there will be considerable noise increase and absolutely NO performance increase! True 'Pancake' filters often restrict airflow - they are too near the carb inlet, and the best is the K&N (or copy) type which are thicker and offer a larger area of filter material to the airstream. If in any doubt - order a larger filter than you need - they are easily adapted to fit if necessary.

Post by **eastona** » Sun Apr 13, 2008 3:12 pm

You're also better off fitting a stub stack(s) inside the pancake(s), whether it's a tall or short filter.

Is it worth it? IMHO the noise increase is a pain after a while, and the small performance gain is barely noticeable. Each to his (or her) own though

Andrew

Post by **bmcecosse** » Sun Apr 13, 2008 10:29 pm

By and large on a standard engine there will be no improvement. On a modified engine - then yes the standard air cleaner is a restriction and can be usefully changed for something more free flowing. Rather than stub - I simply generously bellmouth the carb body which has the same effect (elimination of 'vena contracta') without the expense!

Post by **rio678** » Tue Apr 15, 2008 8:49 pm

1 1/4 SU Carb fitted

so definatly not standard, will have a look around for a standard air cleaner.

Post by **bmcecosse** » Tue Apr 15, 2008 10:27 pm

1 1/4 " IS the standard SU carb on a 948/1098 Minor.