Hi,
I've watched the discussions on this site for a long time, as some of the topics discussed are relevant to my build, a very modified Triumph Herald with a Rover V8.

What's the connection with a Locost? Well, I've already fitted a Sierra diff, a custom double wishbone rear suspension with coilovers, and will have some halfshafts made up in the New Year. I'm working on the front suspension at the moment, and have a question.

Background: To put a significantly modified car on the road here in New Zealand we have to have it 'certified', and the engineers I've spoken to refuse to certify a modified car with the Triumph front uprights and trunnions. The Rover motor weighs less than a Triumph six, but the trunnions have a long history of failure, so I've been told to fit another type of upright with proper ball joints top and bottom. The best option, and one that works with the Sierra rear stud pattern, is to use Cortina uprights.

My question is, do Escort Mk1 ball joint tapers fit in the tapered steering arms on the Cortina uprights? The 1/2"UNF thread is, I believe, identical to that of the Herald rack, and hopefully the rack is the right length for the Cortina steering arms.

I've already bought the uprights, hubs, and Maxi bottom and Cortina top joints, so I can get on with designing the wishbones. (I wish I could use Transit balljoints for the top link and make it all adjustable, but again the engineers have vetoed this idea as not using a part for its intended purpose). The Triumph's camber and castor are adjusted via shims behind the lower wishbone chassis mounts, so it will still be as adjustable as the original design. Does anyone have any suggestions on how to optimise the design? Move the upper or lower wishbone chassis mount points, for instance?

Cheers,
Nick Moore

I don't think so, if I remember correctly thats why I had to modify my lower wishbones to fit the cortina balljoint cos the taper was different.

who are the engineers?

Hi Nick,

To fit the Cortina taper I am quite certain that you will need what is known as the "Green" track rod ends from the MK1 RS2000 Escort these convert from the imperial rack thread which is smaller than 1/2" more like 7/16 UNC size to the taper of the Capri/Cortina size steering arms.

Standard MK1 TRE's will not fit.

Get the rack threads confirmed between the Triumph and Escort racks.

The operating geometry of the Cortina upright is significantly different to the Herald one and arguably inferior.

Cheers

Andrew

Thanks for the replies.

Andy, you're right, the Herald rack is slightly smaller than 1/2" diameter on the unthreaded portion, not exactly 7/16, but definitely not 1/2". There's a rally outfit in town (http://www.palmside.co.nz/) who may have some green track rod ends in stock to try. I'd like to avoid having to make up adapters if possible!

As for the geometry, some Triumph people criticise the Herald/Spitfire setup too. I'll try to build in as much adjustability as possible. There's also some scope for moving the rack around to keep the steering arms parallel to the lower wishbones and control bumpsteer.

Goodall, I'm using Wayne Martin as my certifier. There're a couple of other engineers around town, but several friends who've been through the process recommend Wayne as being very reasonable. Another engineer, for instance, insisted a friend's Vitesse brake lines be re-routed after he fitted a Toyota gearbox, despite them still being in the factory positions! And Wayne's actually enthusiastic about cars, rather than trying to discourage home builders.

Thanks for your help. So far fitting the engine's been the easiest part!

Nick

Nick
It looks from the picture as if you have fitted the Sierra diff upside down. If you have wont it be turning in the wrong direction?

oh right just most people on here hust self evaluate the sutuation, just seemed abit odd

the rear setup in the is awful, good thing your changeing it

[Edited on 30/12/06 by goodall]

Eeeek, diff upside down? That had me doing a few quick checks! Nope, it's the right way up, I think the photo perspective is a bit misleading. The chassis is actually leaning up against a wall in the shot, with another Herald chassis behind just to confuse things. But it's definitely the right way up!

Spent some of yesterday looking on the net for green track rod ends. There are several suppliers selling them for Mk2 Escorts, but I think these had the metric-threaded rack? Does anyone know where I might find some Mk1 RS2000 track rod ends? Or what their part number is?

Goodall, there are others who could tell you some stories about the vehicle certification process - I try and learn from them! While the aim is to keep unsafe vehicles off the roads, like the global safety industry, it's grown into a paperwork monster. Certification can be difficult if you just launch into a project without talking to a certifier first. Most things allowed overseas are OK, but it pays to check. A lot of welding, for example, has to be done by a professional, and some welds have to be X-rayed before road use. And major structural changes, such as chassis bracing and wishbone fabrication, have to be documented - plans, stress calculations and loading figures, for example. A pain in the bum for a home builder, but a lot of fabricator/engineers are set up to do the work and provide the paperwork.

The standard Herald rear end is fine in its original setting, ie a 948cc Herald! However, even a Vitesse's torque distorts the transverse leaf spring and creates some interesting geometry changes on acceleration, so when I decided to fit a V8 we built some meaty double wishbones. Not lightweight but very strong!

Mk1 Escort & Triumph Herald (& also BL Mini track rod) ends use a both different taper and thread from the MK2 Escort and Cortina Mk3-5 -- no chance of making one fit the other.

However it might just be possible to use Triumph TR6 or Triumph 2000 (nb only from the non power steering version) track rod ends to mate a Herald rack to Cortina uprights, I know the threads will fit but I am only guessing at the tapers.

It is a pity that the authorities in your country take such a strange attitude to the Alford & Adler front suspensions as used by Triumph as there is nothing wrong with the design if maintained and not over loaded, it has a long track record of success including use in F1 and in the Indianapolis 500 and in the Le Mans 24Hour race.

The Herald rear suspension is however deadly as it is a very poor example of a swing axle.

Didn't the MK1 Rs2000 use imperial threaded track rod ends but with the later taper which fits the cortina upright.......I thought they did (the "green" ones were this metric/imperial mix part)

sold by rally design

quote:

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Originally posted by NS Dev
Didn't the MK1 Rs2000 use imperial threaded track rod ends but with the later taper which fits the cortina upright.......I thought they did (the "green" ones were this metric/imperial mix part)

sold by rally design

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ahh yes that would make sense, ok no good then!