Fast Marina Magazine

can some one please tell me the final drives for

1.3
1.7
1.8

im looking at better motorway use, cheers

ps, or alternative axels mgb etc.

Saloon/Coupe/Estate
1.3 = 4.11:1 or late Ital 3.93:1
1.7 = 3.63:1
1.8 = 3.63:1

7cwt/440 Commercials = mostly 4.11:1 but some = 4.55:1

All 3.75" PCD

10cwt/575 Commercials = 4.55:1

4.5" PCD

MGB axles are 3.909:1 and entirely different, slightly narrower than Marina, and 4.5" PCD.

Dolly Sprint axle are entirely different again with 3.54:1 with 3.75" PCD. Also all brackets need cutting off and new ones welded one.

Chris

All the small Triumphs shared the Marina diff (but not the axle housing). The 4.11, 3.89. 3.63 were also used in Spitfires and Dolomites, and a 3.27 in the GT6 and Dolomite 1850 auto. There are forum members who have fitted the 3.27 successfully.

Can someone confirm the 3.93:1 ratio and 3.89:1 and their fitments?

Ben

Ben

3.93:1 was fitted to late Ital 1.3 saloons/estates and various Triumphs.

I'm not aware that the 3.89:1 was ever fitted to Marinas or Itals, it was fitted the Spitfire Mk4 and 1500, also Dolomite 1500. I think that the 3.89:1 diff will fit the Marina axle casing, but I don't know whether the splined section will match a Marina half-shafts. The 3.89:1 crown wheel and pinion can be bought new from Rimmers for about £300 and the fitted into a Marina diff.

That's what I thought Chris. Although I keep finding references to the 3.89 diff on many internet sites and nothing for the 3.93

Who said the Internet was accurate? The web is worse than the proverbial man down the pub.

Obviously, but when you get 10 results with 3.89 and non for 3.93, you start asking questions..

What search did you use?

Dolomite CWP

Morris Ital 1.3 Final Drive

At 4000 rpm the 3.27 would make a 400 rev difference over the 3.63
- that represents an extra gear.

It would make moving off slightly slower, but sounds very worthwhile for highway use.

Very true for a 1.7/2.0 or 1.8, but I'm looking at the 1.3. A little old A series may be asthmatic with a 3.27!

For the difference between a 3.93:1 and a 3.89:1 you could adjust the performance by different tyre ratios.

True, But what was the 3.93:1 CWP also fitted too? Is it a real differential? Can you see it listed/documented anywhere?

Plus I'm starting with a 4.11:1 on the Mk3