Will my original be ok

[hippybus]

I have a austin Devon Countryman.It has a classic capri rear axle with mgb disc at the front.I would like to keep the standard 16inc wheels.I no it should have 17inc whels.Any way i want to fit fx taxi tyres do i use tubes or with out,what size are fx taxi tyre.With me wanting 16inc wheels will the gearing be ok.Or will i need smaller wheels thanks all

[Adam]

Depends what Capri axle you have. From memory the 3.0 & 2.8 had a 3.08 ratio. The 2L had a 3.44 ans the 1.6 & 1.3 had the 3.91. There should be a tag telling you the ratio on the diff. I'd assume taxi wheels & tires are tubeless. Measure the height of the tire in inches. x that by 1000 (rpm) x that by 0.002975 divide the answer by the rear end ratio. If the answer is anywhere in the 22 - 24 range your about spot on. Anything lower than 20 and the engine could be revving hard at motorway speeds, anything higher is ok but it may be slow off the line depending on vehicle weight.

[poprodder]

i had taxi tyres fitted to a set and in my eyes never looked right, too much
of a bulge. the wheels are designed to have tubes fitted, the tyres are'nt!!!
chris.

[eeb43]

the classic capri axle if original should have either a 3.77, 3.9 or 4.1 diff

[Adam]

Ah blonde moment! I didn't see 'classic' just Capri, sorry.

[kapri]

the classic capri axle if original should have either a 3.77, 3.9 or 4.1 diff


3.9 Option (GT ) or 4.4 ( Special order only ) and 4.1 in all other variants, 3.7 didn't become readily available until the Corsair 2.0 V4. ( Tech advisor to CCOC ;) )

[eeb43]

3.9 Option (GT ) or 4.4 ( Special order only ) and 4.1 in all other variants, 3.7 didn't become available until the Corsair 2.0 V4. ( Tech advisor to CCOC ;) )

seems strange as i have taken 2 3.77 diffs from capri gt axles that were thought to be original

[kapri]

Nope, I guarantee that it wasn't a standard fitment on Consula Capri / Classic . 3.7's were fitted to 'Hockey stick 'capris in the v4 2.0 version .


To pull a 3.7 on 13's you'd need 90-100 bhp. Stock capri 1500 was 54 and GT made 78.

[eeb43]

mk1 and 2 gt and lotus cortinas and 1600e were fitted with a 3.77 diff and most of the mk1 capris with the v4 had a 3.44 in an atlas axle

[kapri]

We seem to have had different experiences , every h/s V4 I've ever pulled apart had 3.7's in an English casing ,strange eh ??? I'll check with my mate who's owned 30 odd Mk1 and 2 Lotiii re the ratios. They are certainly powerful enough to pull a 3.7 but 85bhp 1600 GT would be pushed I'd have thought.

Thing is it's difficult to tell whether the diff has been played with ,by previous owners ,on a motor thats got 30 - 40 years worth of crud on it. Like I said 3.7's I can say without doubt weren't even an option on a Classic / Capri .

[hippybus]

So in a nut shell i should use 13inc wheels and not the devon 16inc with taxi tyres.I only wanted to keep it lookin standard.:mad:

[kapri]

16 inch tyres used on say a 4.1 that had 13's on would be the equivalent to about 3.7 on 13's .

What engine are you using and with what bhp ??

Kev

[hippybus]

Hi the engine is a 1800cc marina.Thanks

[Adam]

Use the formula and see what it works out as.

[kapri]

You forgot the formula Adam !! LOL

Depending on tyre height the 4.1 MAY be suitable as the 1.8 is a torquey lump ,but to be safe I think I'd look for a 4.4 .

[Adam]

You forgot the formula Adam !! LOL

Depending on tyre height the 4.1 MAY be suitable as the 1.8 is a torquey lump ,but to be safe I think I'd look for a 4.4 .

It's on the second post of this thread Kev.

[Dave Lowe]

I have a austin Devon Countryman.It has a classic capri rear axle with mgb disc at the front.I would like to keep the standard 16inc wheels.I no it should have 17inc whels.Any way i want to fit fx taxi tyres do i use tubes or with out,what size are fx taxi tyre.With me wanting 16inc wheels will the gearing be ok.Or will i need smaller wheels thanks all

Hi Pete, I would go for a 4.4 diff from a 105E anglia van or estate, if you have MGB hubs with the discs at the front, Devon wheels wont fit, they are Ford PCD, TR2/3 15 inch wheels are about the nearest sizewise that will fit.

[hippybus]

Hi Dave i have had the MGB front hubs redrilled and new wheel steuds welded so they now take the devon wheels.I think what i will do is fit Austin A50 original steel wheels 15inc so i can have radial tyres.I have had a look on the diff there is no tag but threr is some numbers and it says 105e.If not i had some ford wheels which were the same stud pattern as the Devon.So i will try 13inc Ford wheels as long they clear the front disc and calipairs.