Triumph Sports Cars

engine swaps and other performance upgrades, plus "factory" V8s (Stag and TR8)

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Incony
Nigel Simon

(2 posts)

Registered:
01/24/2011 06:57AM

Main British Car:


Herald V8
Posted by: Incony
Date: January 24, 2011 07:38AM

Because i am looking at any input from anyone, :)

I am beginning the project of installing a 3.9L 230BHP with a webber/ edelbrock manifold, tuned Rover V8 in my Triumph Herald.. thats the easy bit, it goes almost straight in with a little bulkhead work, new engine mounts, some exhaust fabrication, using the 5 speed manual (uprated clutch ) Rover gearbox... etc. it fits so well, that there will be no bonnet mods... it will look exactly the same. Even the gear stick will be in the same place as the little 13/60 triumph one was. The cooling takes some working out, but its been done before.. so i dont break new ground.

My problem really is the rear axle.. getting the axle shortened ( 6 inches each side ) isnt straight forward.. even though i can get
a complete new Atlas axle for example from Fostek Engineering in the UK .

1. I want a 3.08 ratio Diff, and none of the existing Triumph ones are close..
2. if i can use the existing method of half shaft, rear spring arrangement, then it means i wont have so much to redefine, but the
Triumph half shafts are really on the borderline for 230 BHP.

So.. i am looking at a Quaife LSD.. [www.quaife.co.uk]
and these half shafts for a TR6 - particularly the Heavy Duty Types... [www.goodparts.com]

I just wanted to bounce the idea of you all. Everyone will have their own preference,

Mine is.. easy availability and continuity, Triumphs and the Rover V8 have good spares availabilty still, so anything that i can keep as standard as possible, means its easier for maintenance, and sourcing..

So.. if i keep the rear axle ( not the hubs - Herald rear brakes suck ) for road use.. not racing and spend effort on chassis strength,
and better wheels, brakes, half shafts and diff.. its the road i want.

?
fujifinepics100820008 001n.JPG


Bill Young
Bill Young
Kansas City, MO
(1337 posts)

Registered:
10/23/2007 09:23AM

Main British Car:
'73 MG Midget V6 , '59 MGA I6 2.8 GM, 4.0 Jeep

authors avatar
Re: Herald V8
Posted by: Bill Young
Date: January 24, 2011 07:58AM

Nigel, several here in the US have been working with rear axle swaps using either Nissan or BMW differential assemblies and upgraded half shafts as you are planning. If you retain the original gear carrier you're still stuck with a small ring gear diameter that is not up to the torque specs you'll be putting out and a poor choice of gears. Take a look back through the archives, do a search for BMW rear axle and I think you'll find the post I'm thinking of. Using either the Nissan or BMW assemlby will really open up the gear ratio selection as well as increase the torque capacity.


Incony
Nigel Simon

(2 posts)

Registered:
01/24/2011 06:57AM

Main British Car:


Re: Herald V8
Posted by: Incony
Date: January 24, 2011 11:41AM

Thanks Bill,

Using Google i just searched using BMW E46 3.08 Differential.. i found no certain sources but lots of talk..

sure.. second hand, but even adding "buy" to the search it wasnt good..

and the prices.. compared with bugging Quaife and who ever, can get me a Triumph or Rover Diff up to spec, was nearly the same..

Its why ive looked at getting the Rover axle shortened... ( ive the complete SD1 to break.. i bought it for that engine ) it can be done, i know folks who think they might have the right spline cutters.. but is still a long drawn out solution.. since its a live axle..like the Atlas..

I looked at the MGB and TR7 solutions here, in "How it was done" using Rover V8`s and not one used a BMW diff.. many still are using the stock set up... ok if it was a V8 axle spec.. but scary if not..

Sadly the MGB V8 axle and TR7/8, is too wide for the Herald.. and given that ive an axle already in the Rover... why go that road at all... :)


I know folks have got the Triumph Vitesse 6 up to 150 BHP on its standard diff... but you sense also my hesitation, if ive got 80 more.

If i can get a 3.08 Diff that i can mate with those TR6 Heavy Duty Half Shafts.. i get to use a tried and trusted solution.. i know folks hate the Heralds negative camber... but its so predictable... one can slide on ice and steer still.. :) and leaf springs .? i can get those for the price of a beer... .. i can still get a complete Herald on EBAY, for less than the price of one those Heavy Duty TR6 half shafts.... :)


The BMW diff, pic i found looks as though it might work.. but i need a firmer footing than that.. and certainty of spares.

DO you know good sources for the BMW diff, and the Nissan Diff? IF.. i could find a reliable source for the BMW diff... either here or in the USA.. i like the solidity of german engineering.

The best source so far ive found, is EBAY, they have 3.08 E46 Diffs, from the 3 series for example.. for @ £ 95.00

it would seem that those on the BMW diesels had a lower ratio, and those on the 1.8`s and 1.9`s were around 3.07 ratio.. they also
have a carrier, that one can see on EBay.. in some sellers pics. The carrier might be usefull to fix to a chassis... but i sense one could
adapt the old Herald mounting wings and bush assembly to fit in the right place.. one might need to fabricate a method of anchoring the "top" of the Diff, as the Herald uses a four stud bracket.. i also sense the six bolt flange fixing is very similar to the TR6 Heavy duty Duty Half shafts i am looking at. but.. i am impressed with what i can find on EBAY.. i have an obvious question though... would a 3.08 E46 diff from a 1.8 or 2.5 etc.. be good enough for 230 BHP?

Since writing this post i see that diffs using the E39 series are certainly good for 193 BHP, and have the 3.07 ratio... thats good enough for me.. since 193 to 230, is marginal, 40 BHP... i know now that thanks to Bill Young, i see the light :)

I want a BMW diff and modified TR6 heavy duty half shafts... i am all but on the edge now, of getting what i want. TY for that Bill.



Edited 4 time(s). Last edit at 01/30/2011 01:54PM by Incony.


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