Special Front Hubs/Uprights

[BDA]

When I built my car, I don’t remember being concerned about which upright was for the left or right (which is not to say that I wasn’t actually concerned at the time). How can you tell the difference between the left and right uprights? Do they only fit one way?

[jbcollier]

From the manual:

The vertical link and bronze trunion on the left hand side of the
vehical has a left hand thread and those fitted to the right hand
side of the vehical have a right hand thread. The right hand
threaded trunnion is turned down at its lower end for identification
purposes.

[BDA]

Thanks JB! I remember now that I did pay attention to that!

[GavinT]

I have GT6 hubs and they fit on the standard stub axle but I don't believe the standard brakes will fit. I went to vented front discs that I got as a kit from Richard when I built my car many years ago so I can't be absolutely sure

Is that correct?
It was my understanding that the GT6 hubs used a beefier spindle and commensurately larger bearings, no?

I don't suppose you still have the GT6 rotors around?
I'm looking for dimensions.

[EuropaTC]

It was my understanding that the GT6 hubs used a beefier spindle and commensurately larger bearings, no?
I don't suppose you still have the GT6 rotors around?
I'm looking for dimensions.

The links/stub axles/hubs on our cars are basically Herald from 1959-63 vintage. Early Spitfires were the same but I'm not sure when they changed to the link with cast caliper mount/steering arm, I thought Mk4 but could have been Mk3.  (from a production viewpoint, that's a big time saver on assembly so you can see why they did that)

I don't have dimensions to hand but the part numbers are;

Part Numbers (Unipart) for the early Herald & Lotus Elan with bolt on wheels, all Europa.

Vertical Link : 205483 (R) 205848 (L)   
Stub Axle :  132488
Inner bearing : 100573
Outer bearing : 100536

For the GT6/Vitesse & Lotus Elan+2, Lotus Elans with knock on wheels

Vertical Link : 209072 (R) 209073 (L)   
Stub Axle :  132665
Inner bearing : GHB101
Outer bearing : GHB102

Hubs are different internally for the bearings but IIRC they look the same externally.  The smaller 232mm discs will fit on either hub, as will the larger (GT6) 245mm discs. The 2 seat Elan uses the 232mm disc for both bolt on & k/o wheels & a common upgrade is to bolt on the 245mm discs, calipers & required mounts on the vertical link.

Discs:
Elan, Spitfire, Herald
Diameter 232mm, Thickness 10mm, Height (from hub) 27mm

Elan +2, GT6 Vitesse (2L)
Diameter 245mm, Thickness 13mm, Height (from hub) 28mm

Brake Calipers:
Type 12 & 14 as fitted to Herald, Spitfire, 48mm diameter pistons
3.25" (82mm) bolt centres on mounting lugs. Use either a bolt on mount the vertical link or the complete cast link.
Type 16 as fitted to GT6 & 2L Vitesse models 54mm diameter pistons
3.5" (88mm) bolt centres on mounting lugs, used only a bolt on mount (which is interchangeable with the mounts on our cars)

All from when I did my brakes......

Brian

[4129R]

I have GT6 hubs and they fit on the standard stub axle but I don't believe the standard brakes will fit. I went to vented front discs that I got as a kit from Richard when I built my car many years ago so I can't be absolutely sure

Is that correct?
It was my understanding that the GT6 hubs used a beefier spindle and commensurately larger bearings, no?

I don't suppose you still have the GT6 rotors around?
I'm looking for dimensions.

I think I may have some GT6 disks/rotors. What dimensions do you need?

Diameter, thickness? 

[MRN I J]

So, I am lost.  The Europa suppliers of alloy hubs know though.

I bought my alloy hubs from the premier Elan racing guy in the uk, Tony Thompson Racing as I had heard so many horror stories about the bearings coming loose, his have a very large interference fit so that they dont.

My uprights are 1990 Caterham 7 with spherical bearings at the bottom instead of the trunnion

[BDA]

I have GT6 hubs and they fit on the standard stub axle but I don't believe the standard brakes will fit. I went to vented front discs that I got as a kit from Richard when I built my car many years ago so I can't be absolutely sure

Is that correct?
It was my understanding that the GT6 hubs used a beefier spindle and commensurately larger bearings, no?

I don't suppose you still have the GT6 rotors around?
I'm looking for dimensions.

Let me say first that it was over twenty years ago when I built my car so some of the finer details of it are sliding into a deep age related black hole. I will say that I sure (still constrained by the DARBH noted earlier) that I did not change my uprights nor my stub axles.

My GT6 parts were from a kit from Richard so I don't have any other GT6 parts lying around. Sorry.

[GavinT]

I think I may have some GT6 disks/rotors. What dimensions do you need?

Diameter, thickness?

Yes, that'd be great, thanks.

I'm researching the feasibility of bolting a GT6 rotor to the stock Europa hub.
It's easy enough to find the GT6 rotor OD but other important dimensions are more elusive.

Discs:
Elan, Spitfire, Herald
Diameter 232mm, Thickness 10mm, Height (from hub) 27mm

Elan +2, GT6 Vitesse (2L)
Diameter 245mm, Thickness 13mm, Height (from hub) 28mm

From this, it appears the GT6 rotor is only 1mm taller. I had wondered about this because the stock discs run quite close to the steering arm ball joint.

What is the ID of the GT6 rotors?
Brian says they are interchangeable, so I presume the rotor ID is the same?

Type 16 as fitted to GT6 & 2L Vitesse models 54mm diameter pistons
3.5" (88mm) bolt centres on mounting lugs, used only a bolt on mount (which is interchangeable with the mounts on our cars)

Hmmm . . .
Does this mean a Type 16 calliper will fit a stock Europa upright using the GT6 calliper mount?
The GT6 stuff seems more interchangeable than I'd imagined.

My GT6 parts were from a kit from Richard so I don't have any other GT6 parts lying around. Sorry.

No worries, thanks, BDA.

[4129R]

I think I may have some GT6 disks/rotors. What dimensions do you need?

Diameter, thickness?

Yes, that'd be great, thanks.

I'm researching the feasibility of bolting a GT6 rotor to the stock Europa hub.
It's easy enough to find the GT6 rotor OD but other important dimensions are more elusive.

Discs:
Elan, Spitfire, Herald
Diameter 232mm, Thickness 10mm, Height (from hub) 27mm

Elan +2, GT6 Vitesse (2L)
Diameter 245mm, Thickness 13mm, Height (from hub) 28mm

From this, it appears the GT6 rotor is only 1mm taller. I had wondered about this because the stock discs run quite close to the steering arm ball joint.

What is the ID of the GT6 rotors?
Brian says they are interchangeable, so I presume the rotor ID is the same?

Type 16 as fitted to GT6 & 2L Vitesse models 54mm diameter pistons
3.5" (88mm) bolt centres on mounting lugs, used only a bolt on mount (which is interchangeable with the mounts on our cars)

Hmmm . . .
Does this mean a Type 16 calliper will fit a stock Europa upright using the GT6 calliper mount?
The GT6 stuff seems more interchangeable than I'd imagined.

My GT6 parts were from a kit from Richard so I don't have any other GT6 parts lying around. Sorry.

No worries, thanks, BDA.

You are in luck.

Standard Spitfire/Europa disk/rotor

Diameter 232mm thickness 10.5mm

Caliper 168mm in total length

GT6 disk/rotor

Diameter 244mm thickness 13mm

Caliper 186mm in total length

Both hubs are 139mm in diameter and look identical

Both uprights look the same.

Let me know if you need any more info. I have the bits lying around with easy access.

[EuropaTC]

I'm researching the feasibility of bolting a GT6 rotor to the stock Europa hub.
It's easy enough to find the GT6 rotor OD but other important dimensions are more elusive.

Hmmm . . .
Does this mean a Type 16 calliper will fit a stock Europa upright using the GT6 calliper mount?
The GT6 stuff seems more interchangeable than I'd imagined.

Ok.... 

My Elan has k/o wheels which means it has the GT6 uprights and as far as I remember, the larger bearings in the hubs.  It normally comes with 232mm discs, type 14 calipers and caliper mounting brackets the same as the Europa. 

A very common mod (which I've done) is to fit 245mm discs, GT6/Vitesse caliper mounts and bolt on type 16 calipers.  So I can't see why it wouldn't work on the Europa, you might need to space the hub bearing a fraction but I'd bet it's do-able.  But before you go rushing out to buy the bits, is it really a good idea ?

Personally I'd say no. It does make an improvement in stopping power and IMO balances the Elan's brakes better than stock, but with the Europa all you'll do is boost up the front which is already way ahead in braking force compared to the stock rear drums. 

I did it on the Elan because it was cheap & needed more front brake. But the downsides are that type 16 calipers are very, very heavy compared with type 14, plus they have larger pistons so you need to shift more fluid. Not a lot, but another consideration.

Incidentally I have tried the 14 calipers to see if they'd take the wider GT6 discs (I'd make some custom mounts) but on version of the type 14's I have it just looked a bit too tight. Only 3mm more on the disc thickness but it didn't leave much room on the caliper and I wasn't prepared to grind them down. I never got around to checking piston retraction/brake pads, I gave up when I saw how little clearance there was.

Knowing what I do now, if I was doing it again I'd either find a larger disc that would slot inside the Type 14's & make a custom mount to get the caliper further out, or find different calipers and fit the biggest discs I could get under the wheels.

Which is probably what Richard did when he designed his own kit rather than offer a "GT6" style conversion, (which would have been easier/cheaper).

[GavinT]

Thanks to all.
It appears the Europa and GT6 rotors are interchangeable on the Europa hub.

But before you go rushing out to buy the bits, is it really a good idea ?

Personally I'd say no.

Yes, agreed. I'm only considering this in conjunction with rear discs.
I hadn't properly considered a larger disc that would fit inside the Type 14 callipers - good thought.

The reasoning behind all this is an attempt to discover a reasonably cost effective improvement for a four wheel disc arrangement. This is mostly a vision in my head at this point.
One of the starting assumptions is that if we can lock a wheel multiple times in succession, then the brake is sufficient and more dollars are better spent on stickier tyres.

The GT6 disc would be a bit heavier but provide a little more heat sink mass and a little more (13mm) leverage advantage for the calliper. Perhaps GT6 discs are unnecessary.
I've yet to nail down a calliper but it seems there's a remarkably similar sized unit as fitted to Alfa Romeo's of the day which are aluminium, so that should offset a heavier disc.

For the rear, I'm envisioning MGF discs as has been used by others and has the same PCD but am yet to figure out a suitable calliper. Primarily, I'm considering a 36mm piston and including a Tilton proportioning valve.

According to the spreadsheet, this should all work and with slightly less pedal effort on a stock 0.70 master cylinder as on an S2.
All these are off the shelf parts at reasonable cost with the only fabrication being calliper brackets, and maybe the fronts can use stock GT6 brackets.

Comments, criticism, bright ideas & ponderings welcomed.

[EuropaTC]

I hadn't properly considered a larger disc that would fit inside the Type 14 callipers - good thought.

The reasoning behind all this is an attempt to discover a reasonably cost effective improvement for a four wheel disc arrangement. This is mostly a vision in my head at this point.  One of the starting assumptions is that if we can lock a wheel multiple times in succession, then the brake is sufficient and more dollars are better spent on stickier tyres.

I went the GT6 route with the Elan simply because others had done it, but having been there I decided not to do the same with the Europa despite it being an easy option. Type 16 calipers are both big and heavy in comparison with the 14's (see pic) so if you can get a 245-250mm disc to fit the type 14 then I'd go for it. (the first thing I tried for the Europa was to get a T14 caliper on the 245mm GT6 disc)

I can't fault your logic on the "locking brakes vs tyres"" aspect, but remember that's with rear drums and a known problem with these cars. The balance will change with rear discs of any nature. 

I've yet to nail down a calliper but it seems there's a remarkably similar sized unit as fitted to Alfa Romeo's of the day which are aluminium, so that should offset a heavier disc.

For the rear, I'm envisioning MGF discs as has been used by others and has the same PCD but am yet to figure out a suitable calliper. Primarily, I'm considering a 36mm piston and including a Tilton proportioning valve.

I'm very interested in your comment about an Al. caliper, if you get some then please post pics & details. One of my problems is that when doing these sorts of projects I don't have a wider knowledge of what's fitted to other cars or is on the market, it's always guesswork and luck.

For my first conversion I used MGF discs at the rear but with 34mm pistons in Renault Scenic calipers. 36mm is a good call and gives you a better balance, do you really need a proportioning valve with that ?   I opted for 34mm because they seem to be one of the most common sizes over here and although not as good as 36mm, it was an improvement in balance over the drums.

I think you'd be pleased with the OEM 232mm fronts in combination with the MGF discs. I ran that combination for a while and considered it a worthwhile upgrade. I only went to bigger discs all round because, well, I've got 15" wheels and the space to do so. My pedal pressure, even without a servo, is low and feels very much like a modern car - which was the main objective of larger discs.

Anyway, the point is that I've got 265mm discs on Type 14 calipers so if you can find a 245/250mm disc that can be re-drilled to fit then I think you'd keep the 13" wheels & have great balance/brakes.

Brian

[Bainford]

Nothing to add, Gavin, but I'm very interested in your project and findings. The aluminum calipers are intriguing. The effects of unsprung weight on a lightweight car should not be underestimated.

[GavinT]

Crikey, those Type 16 calipers really are a lot bigger.

Re the alloy front callipers, they're supposedly a common Alfa unit with a 48mm piston like the stock Europa.
This is something a friend had chased down some time ago but I've hadn't followed up.
I've no info on how they might relate to Europa disc position or mounting bolt spacing etc.
I've sent a message so hopefully there will be something definitive coming back.

From what I can discover, 34mm piston rear calipers are a fairly common spec.
The 34mm VW Polo ones look very nice and compact. I thought early Golfs had 36mm rear calipers?
I think Toyota MR2 used 36mm rears, too.

Is 38mm too much?
In the UK there's plenty of cross-over to VW Passat, Golf. Audi and Skoda etc. like these:

https://tinyurl.com/eyvncpna

The 36mm caliper I'm considering is from a Nissan Skyline R31 (stolen pics below). I have a new unit which came from a mate who worked at PBR here in Oz at the time. Also have a pair of 40mm ones (same style) they were developing for an American Corvette of the time - probably too much for a Europa.

No, I don't really know for sure if a proportioning valve will be needed. The spreadsheet says it's on the edge and it's probably more insurance than anything in case wet roads call for backing off the pressure.
That's reassuring news on pedal pressure, though. I reckon 15" wheels are the way to go but kinda still want to get the brakes inside 13's - but maybe that's silly.