4.22 Diff in an 803?

[Mr Morris]

Has anybody tried a 4.22 diff in their 803cc engine? I was wondering whether it would not have enough power but some people say it's and other don't

[bmcecosse]

Depends if you have many hills around you...... In Norfolk I would say fine! Actually - it's probably fine most places unless VERY hilly.

[mike.perry]

You would be lucky to manage to get into 4th gear with a 4.22 diff, especially with the gap between 3rd and 4th in the gearbox.
Then consider the problems of getting a calibrated speedo to match an 803 box and 4.22 diff

[bmcecosse]

Easy! Swap to a 948 box........and get the better 3rd gear too.......

[mike.perry]

What year Series 2?

[JOWETTJAVELIN]

It seems to me the whole 803 package is useless, so I would consider changing the engine and box for more power and better gear ratios, as suggested.

In standard form the 803 4th gear (direct drive?) can be used at 20 MPH on the flat up to about 45 MPH before things start getting frantic.

Correct me if I'm wrong but a 4.22 diff won't improve the already sluggish performance.

[Mr Morris]

Thanks everyone yes 45mph is about tops. I may consider swapping the engine I'll have a think !

[mike.perry]

Do you have the early Morris axle or the A Series axle? It makesa big difference to what you fit

[liammonty]

For goodness sake don't bother with a 4.22! I don't think it would even be that happy with a 4.55- the engine just hasn't got enough torque. The series MM pulls a 4.55, but the engine is far more robust. As I (and countless others) have discovered, the 803 just isn't up to hard work... I found 948 running gear was lovely in my S II, easy enough to change a 948 box to the long gear lever. If you go down this route though, be sure to change the gear in the box that drives the speedo drive as the ratios are totally different between the S II and the 948. Incidentally, brakes on the S II are the same diameter as on the 948, so the mods wouldn't make the car any more 'dangerous' than a bog-standard 948 car.