1990 Caterham HPC?

[snapper seven]

Isn't a Lotus S4 chassis quite different to an S3. Different bulkhead and front section where the rack and suspension mount?

I am not expert but not sure if an S4 could be converted to be an S3, though could it be reskinned as an S3? Maybe it can and hopefully someone will confirm. I am only saying this as the photos of the cars are S3s. Edit to add - just realised I have made that assumption but you can't see much of the car in the photo and S4s have been converted to cycle wings. Do you have more pictures? /edit

I suppose it is possible that someone approached Lotus and convinced them to build an S3 even though S4s were in full production and therefore taking the next chassis number??

Cheers
SS

Edited by snapper seven on Wednesday 30th January 14:18

[EFA]

An S3 has no similarities to an S4. A beach buggy is more like an S4 than an S3.

[henkg]

Hi Guys

The serialnumber points to Lotus S4 (1972), but it looks like an S3 (see picture).
http://thumbsnap.com/sc/YQPv9hmC.jpg
I am confused.

It's also shorter than the Caterham from 1987 which i fitted earlier.
The Caterham fitted (no SV) but in this Lotus i need about 4 inches more legroom.
Opened up a new topic about this (Moving pedalbox).

Thanks to all for your help and information !
Henk

[BertBert]

Standing back for a minute... are you sure you want 2.0l cossie turbo powered 1972(ish) S3(ish) Lotus/Caterham (ish)?

That's quite a niche combination and not to all tastes (read not mine!)

Bert

[NuisanceFactor]

henkg said:

Hi Guys

The serialnumber points to Lotus S4 (1972), but it looks like an S3 (see picture).
http://thumbsnap.com/sc/YQPv9hmC.jpg
I am confused.

It's ever so easy to move a chassis plate from one car/chassis to another, this wouldn't be the first Lotus 7 S4 turned into a S3 that I've heard of.

[KaKow]

Regarding Caterham AM84131 - can anyone tell me where I can go to determine if this vehicle was manufactured in the UK? I'm trying to figure out if the vehicle came off the assembly line as a complete vehicle - or if it was sold as a Kit. Any ideas?

[Canuck7]

Here's a Video of the car in question, for those who know more than I;

https://www.youtube.com/watch?v=zjZSLfg6o0k

In the still photo in the above post, parts of it look like a Birkin, lol. (Roll-over bar, front turn signals). I'm not as familiar with the Lotus S3s of the 70s, so can't comment on that familiarity.

I have a 1991 DeDion S3 extended cockpit with a Cosworth built normally aspirated YBM engine for group A rally (?) squeezed into it. It requires some frame mods to work easily with the T9 gearbox. Front diagonals need to be shortened. Cosworth states it makes 210 HP, 176 ft/lbs with 11.4:1 forged pistons and L2 cams. Their full-on race versions run 12.8:1, ported heads, and makes something like 280(?). (Some day I should ask Oilyhands some questions about tuning mine.)

It only adds maybe 35 lbs over a standard caterham large displacement engine of the time.

It seems to be about enough power. :-D

A tweaked turbo engine would be more than exciting. The fact this one does fit in there, and all that, should point to a reasonable upgrade job. You might want to check that the sump isn't too low and what they may have done to the frame around the engine - I have a titan dry sump oil system for clearance.

If you aren't concerned about true "collector" status, and the parts on this car are sound, then you'll have plenty of fun in this car. You'll be glad they put some wilwood big brakes on it.

I'd advise being very careful with it for the first few weeks, or it might bite you.... ask me how I know... ;-)

[rotorwings]

I like how his head sits nicely above the roll bar at 2:15 in the vid

[IBDAET]

That car is no Caterham or Lotus 7. Front suspension is totally wrong fro a car of that era.

[Skyedriver]

The dash on that car is flat and pop rivetted across the front. A caterham or Lotus would be wrapped around the lower tube and popped underneath
One to many 2" guages
Sits very high at the rear
Agree possibly a Birkin roll bar. - Useful if you roll the car and don't want to keep the top half of your head.

[My Evil Twin]

I would also agree that its not a caterham or Lotus...

also AM84131 is NOT a VIN of a Caterham or Lotus...
its just the number 'Arch Motors' stamped into the chassis when it was on the jig... in much the same way your everyday car has part number molded into the plastic bits.. the number is just for tracking the parts in stock before thay are all put together to make a car.

Once Caterham build it.. it would get a VIN... see the 7faq link in a post above for more info on what a correct VIN looks like.

[KaKow]

Thank you Evil Twin. Unfortunately the 7faq site requires membership. I've applied but not certain how long it will take. Your reply is very helpful and appreciated.

[My Evil Twin]

Well..
I cant remember what the format of the older chassis numbers is now...

but I do know that a old '84 Caterham I looked after for a while didnt have a chassis number on it.. and we looked EVERYWHERE. had a AM# tho.. so maybe yours slipped by also and being overseas, they just took the number that was stamped into the chassis.

it was 99% orignal aswell.. only part on it not fitted by the factory was the water temp gauge as the orignal had given up the ghost.

edit:
but then again.. 1990, they would have been in gear for the Euro spec VINs at that time.. not the old Caterham "stamp some semi-random number on it somewhere" system

Edited by My Evil Twin on Tuesday 25th November 20:02