Lotus 7 - S4

[Mick O'Malley]

I couldn't either.

The nearest I found were these, which you probably already have:-

The front suspension

The front suspension of the Seven S4 uses the links, anti-roll (sway) bar, and bushes from the Lotus Europa. This had two advantages:

The parts were cheaper and readily available in the factory parts bin.
Abandoning the Lotus 12 type front suspension (in which the upper wishbone was actually comprised of a single top link and the anti-roll bar) meant that the Seven had a true double wishbone front suspension for the first time.

The uprights, also used in the Europa are originally Triumph in origin, as used in the Herald and Spitfire. The brake discs and callipers are also Triumph, but the hubs are of Ford origin and have a 41/4” stud pitch matching the Ford sourced rear axle. Table lists a summary of the nut and bolts used in the front suspension of the Lotus Seven S4.
Selected list of nut and bolts used (in one side) the front suspension of the Lotus Seven S4. Application Size
Upper wishbones, anti-roll (sway) bar link, and upper shock (damper) to chassis 1/2” nyloc on threaded pivot pin
Lower wishbones to chassis 1/2” nyloc
Lower wishbones to lower shock (damper) 1/2” x 21/2” & nyloc
Lower wishbones to trunnion 7/16” x 23/4” & nyloc





Apologies if this disappoints.

A subsequent search on a Europa site yielded this: http://www.lotuseuropa.org/images/WorkshopManual/S...

Edited by Mick O'Malley on Wednesday 13th April 09:51

[7s4whatelse]

And the origin can be found in the great Tony Weale book "Restauration, Preparation, Maintenance, page 133

Just send a photo of the issue and it would be easier to help

[richardl7S4]

Thanks Hajo,

I'm calling on Redline next week, so will get a couple of new engine mount feet before starting to get the engine realigned.

Richard

[uglyduck]

Thanks for the effort Mick. I do have all the Europa measurements for the front bulkhead but even though the suspension is the same, the track is narrower on the 7S4. I can use the Europa geometry as a base line and extrapolate for the 7. It will likely be close. It would be good to get chassis drawing at some point if further chassis repairs are needed in the future.
Thanks

[Buckssa]

Can anyone suggest at what stage of rebuild to send for painting. Currently the car is a rolling chassis without engine and drive train., I'm leaning toward inserting the tub, installing all the fiber glass but leaving the engine and drive train out then sending for painting and complete final assembly there after.

[7s4whatelse]

@Buckssa

It is a good practice to complete your rolling chassis with the complete "powertrain" (except gearstick) and then to add the fresh bodywork, so you minimize new scratches caused by the final installation work. Then add the wiring loom and the pedalbox, steering column, speedodrive etc. etc.. Bodywork is best supported by two, as it is a little bit fragile in the rollbar region. All is a very straight forward procedure.

[swompy62]

Hello S4 lovers, Im in the process of restoring a original 1971 Lotus s4 1600 GT.
I live in Chester and am in need of a few tips as some parts of mine are missing.
Can anyone tell me what bonnet catch / lock was used I have the platform but nothing else
also would anybody know what radiator was used and from what car
last but not least where would I get a Plastic cloth top 'roof' made I have the original but its seen better days.
Ta.

[richardl7S4]

Hello Swompy

Here are some photos of the bonnet lock and radiator. I've no idea the origins of the lock but the radiator says "Stanpart" so must be Standard Triumph like many Lotus parts. I have used Rimmer Bros at Lincoln for brake discs and calipers, plus various steering gaiters and front suspension joints. They are very helpful but only relate parts to Triumph models, so best to try and find which year Spitfire/GT6 etc Lotus used for the radiator if you don't have an old one to show them. I'm sure some of the more experienced S4 owners can provide more details.

Mick at Redline is very good with information on where Lotus sourced parts for the Seven and he has many parts in stock.

Can't seem to get all photos on one post so will post again.

Good luck.

Richard

[richardl7S4]

[richardl7S4]

[swompy62]

Thanks Very much richardl7S4 for the information I can now see light at the end of the tunnel.
I will try to post a few photos of my S4 project.

[swompy62]

Hello S4 lovers, A few photos of my 1971 factory built 1600 gt Lotus S4.
If you spot the steel plates I had made up to turn the front spitfire hubs into ford 4 1/4 pitch to match the back english axle it is because I could not find anything to match, the hubs never came with the massive box of bits I got when I bought the car. the only information I could find was 'triumph mod' ! so I made some. I drilled out the hubs nominal and fitted longer ht bolts through the whole assembly, I hope its strong enough, any thoughts or advice including the correct hubs would be appreciated. I'm laid up at the moment with a broken leg but i'm itching to get back to preping it for paint probably in the original sky blue.

[swompy62]

[swompy62]

[swompy62]

[Joshrc91]

looks great, I'm rebuilding mine from the chassis up. Have got all the front suspension and steering, but am a having trouble finding a rear axle though. Does anyone know the casing that was used? I understand it was from an Escort Mk1, but there appear to be a couple. Does anyone know the exact axle needed, and whether Lotus used the standard location for wishbones to mount to the chassis?

[anp]

I think the axle is a Mexico with a 3.777 diff that has additional brackets for top links but Lotus added brackets for attaching the shock absorbers and the bottom links and A frames I made one a few years ago from a standard escort mk 1 axle top link brackets you can buy but the Lotus bits you will have to fabricate

[7s4whatelse]

@ swompy62:
Regarding the hubs you have at least 2 options: go for Caterh*** front hubs - I did this and found the Aluminium hubs which have the benefit of less unsprung weight - or have a look at Merlin Motorsports, UK they also have fine examples in their range

[7s4whatelse]

Funny:- I did the same to a MK1 banjo / english axle to convert it to a S4 one. I might still have the drawings for the brackets if needed

anp said:

I think the axle is a Mexico with a 3.777 diff that has additional brackets for top links but Lotus added brackets for attaching the shock absorbers and the bottom links and A frames I made one a few years ago from a standard escort mk 1 axle top link brackets you can buy but the Lotus bits you will have to fabricate

[swompy62]

Thanks 7s4whatelse for the information, I'm kinda hoping my fix will suffice for now but you gave me 2 good leads where to source some from.
anp if you are back from your hols please contact me regarding viewing your s4 as we discussed via texts
Ta.