
Lotus 7 racer with 41 supension - help please!
#1
Posted 04 October 2009 - 18:26
I am having trouble trying to find any information on a Lotus 7 which i have just bought, the car has been off the road for 30 ish years. It was first registered in 1976 but apperntly previous to this it was used on the track. There is no direct chassis number although it does have the number 10948 stamped on the frame in a couple of places. The car looks as if it is a series 2 or 3?? It has been modified to lotus 41 rear suspension with magnesium uprights. The car has a 26r elan diff and is using conventional donuts. It runs 6 stud magnesium wheels 9 inch rear and 7 inch fronts we think these are 41 as well. It is running outboar discs all round and has aluminum girling calipers. the front suspension is a pretty conventional setup but has special front wishbones. There is a very 60's/70's rollover bar wih one strut running back. The car suposedly had a 997 ford engine in it in 1976, but we have 2 dry sumped twincams one by piper, both engines are on 701m blocks one has T&J fuel injection. There is also a magnesium gearbox with aluminium bell housing. Lots of other bits and pieces. The car was owned by phillip kirkham in 1976 and was sold for £2500. We also have a 10000rpm smiths chronometric tacho for it. If anyone has any history or thinks they may know the car please contact, we have seriuosly struggled with identifying it. Many Thanks.
I can e-mail anyone photo's.
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#2
Posted 04 October 2009 - 18:43
BTW - for those who don't know, Dimsomdan has appeared in photographs on TNF in the recent past, having had a key role in the recreation of a certain yellow Italian car...
Edited by Cirrus, 04 October 2009 - 18:45.
#3
Posted 04 October 2009 - 18:58
Hello cirrus! i just sent a load of pics to iain, if you would post some that would be great. i can e mail them to you if you want. Thanks so much for the help.
#4
Posted 04 October 2009 - 19:50
Amazing the parts didn't get 'parted' away from it over the fallow years too. But regular doughnuts with a 26R centre? I didn't know that was allowed.
#5
Posted 04 October 2009 - 19:53
#6
Posted 04 October 2009 - 20:06
Not to mention 26R rear end bits.
#7
Posted 04 October 2009 - 20:37
#8
Posted 05 October 2009 - 07:40
Regards Mike B
#9
Posted 05 October 2009 - 09:00
#10
Posted 05 October 2009 - 09:27
Once identified please post deatils of early ownership as that is more or less ceratin to reveal photos of the car in period.

#11
Posted 05 October 2009 - 16:12
Didn't Tim Goss race something like this in the Clubmans Championship in the mid to late 1960s.Hello there chaps,
I am having trouble trying to find any information on a Lotus 7 which i have just bought, the car has been off the road for 30 ish years. It was first registered in 1976 but apperntly previous to this it was used on the track. There is no direct chassis number although it does have the number 10948 stamped on the frame in a couple of places. The car looks as if it is a series 2 or 3?? It has been modified to lotus 41 rear suspension with magnesium uprights. The car has a 26r elan diff and is using conventional donuts. It runs 6 stud magnesium wheels 9 inch rear and 7 inch fronts we think these are 41 as well. It is running outboar discs all round and has aluminum girling calipers. the front suspension is a pretty conventional setup but has special front wishbones. There is a very 60's/70's rollover bar wih one strut running back. The car suposedly had a 997 ford engine in it in 1976, but we have 2 dry sumped twincams one by piper, both engines are on 701m blocks one has T&J fuel injection. There is also a magnesium gearbox with aluminium bell housing. Lots of other bits and pieces. The car was owned by phillip kirkham in 1976 and was sold for £2500. We also have a 10000rpm smiths chronometric tacho for it. If anyone has any history or thinks they may know the car please contact, we have seriuosly struggled with identifying it. Many Thanks.
I can e-mail anyone photo's.
#12
Posted 05 October 2009 - 17:25
You could also try posting an enquiry on the the simplesevens.com website
#13
Posted 07 October 2009 - 22:23
thanks chaps
Dan
#14
Posted 08 October 2009 - 06:10
Edited by Cirrus, 08 October 2009 - 06:11.
#15
Posted 08 October 2009 - 06:59

#16
Posted 08 October 2009 - 18:02
I'm surprised that nobody has recognised it yet...
#17
Posted 09 October 2009 - 21:09
Blimey Dan, the speed you took that thing apart! You could almost do this for a living.
HFJ Drifter? I wonder who this could be!! ha ha. Well its nearly on its way to going back together. just need the chassis painting and i need to sort out abot a million pop rivet holes before reskining the easy parts. Im thinking about getting a new bonnet and low drag alloy nose made for the front.... do you know anyone that can help.....


#18
Posted 09 October 2009 - 21:27
#19
Posted 09 October 2009 - 21:32
Low drag - on a Seven!HFJ Drifter? I wonder who this could be!! ha ha. Well its nearly on its way to going back together. just need the chassis painting and i need to sort out abot a million pop rivet holes before reskining the easy parts. Im thinking about getting a new bonnet and low drag alloy nose made for the front.... do you know anyone that can help.....
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What next?
Ashtrays on a Triumph Bonneville?
Carbon fibre panels on an ERA?
3.8 litre engine in a C-Type
IRS on a D-Type
FPF in an Elite
FPE in an Eleven
Fibreglass body on a Seven (whoops ! I forgot about the Series 4)
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#20
Posted 09 October 2009 - 21:48
Low drag - on a Seven!
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What next?
Ashtrays on a Triumph Bonneville?
Carbon fibre panels on an ERA?
3.8 litre engine in a C-Type
IRS on a D-Type
FPF in an Elite
FPE in an Eleven
Fibreglass body on a Seven (whoops ! I forgot about the Series 4)
They did run many versions of low drag 7's in the 60's and 70's.... in period, for racing. Period mods are ok arent they.
#21
Posted 09 October 2009 - 21:49

2009 mods - no!

#22
Posted 09 October 2009 - 21:51
Period mods - yes
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2009 mods - no!
No problem then lol.
#23
Posted 14 October 2009 - 22:17
They are Barry Foley, Bob Glass and Denis Greensmith. any help would be greatly appreciated many taks guys and gals.




#24
Posted 19 October 2010 - 19:45
other ways to 'skin the same cat'
http://www.flickr.co...57602273600686/
(the chassis of the mink mentioned above)
Edited by Mistron, 20 October 2010 - 11:03.
#25
Posted 20 October 2010 - 09:11
Edited by Sharman, 20 October 2010 - 09:12.
#26
Posted 02 December 2010 - 18:29
#27
Posted 03 December 2010 - 13:19
Thankyou very much for the information youve given us, it really has been a problem finding people that actually know the cars that were made and raced in period, when i first started talking to people i never new there were so many converted to irs rear ends! Im sure one of the cars mentioned must be ours but finding a definitive id is so difficult and we dont want to get it wrong! I do have some more information on the engines it was running, in amongst all the paper work i found some information to say it was running a 997cc 105e unit and box. but was totally standard, if the race engine blew or was removed for popping in something else that would kind of make sense. The car has progressed quite well but now we have slowed a bit as we have set up our own historic race car prepartion and engine shop so this has taken up a lot of time. It was supposed the engine in the car when bought was meant to be a 1340cc. Many thanks again for the information would be great to have a proper chat at some point were based in the south near Portsmouth
#28
Posted 03 December 2010 - 18:16
#29
Posted 04 December 2010 - 20:19
What you can do is use the "Personal message" functionality. Click on the person's name and a load of details appear (what the person has put in his/her profile); scroll down to the bottom and you'll see "Send message"; click on it and a box like an e-mail opens up. You can say what you want and it's confidential, eg exchanging phone numbers or e-mail addresses so you can communicate directly.I am afraid that I am up in Cheshire so a long way from Porstmouth but would gladly talk to you if you wish. I am still racing; HSCC and Historic F2 with Branham BT23/1, Jack Brabham's F2 car from 1967 so am around the UK and continental circuits. Let me know if you are going to a HSCC meeting next year and I will try to meet you there. I have to say that the coil/damper arrangement in your pics was more like a solid rear axle layout being vertical. I think all the IRS Sevens I saw had inclined spring damper units like FJ/F3 etc in period. Am not sure how I get my phone details to you without publishing them to the world on this forum. If you have links with HSCC ask Alan or Grahame to put us in touch.
Edited by D-Type, 04 December 2010 - 20:21.
#30
Posted 05 December 2010 - 15:51
I am afraid that I am up in Cheshire so a long way from Porstmouth but would gladly talk to you if you wish. I am still racing; HSCC and Historic F2 with Branham BT23/1, Jack Brabham's F2 car from 1967 so am around the UK and continental circuits. Let me know if you are going to a HSCC meeting next year and I will try to meet you there. I have to say that the coil/damper arrangement in your pics was more like a solid rear axle layout being vertical. I think all the IRS Sevens I saw had inclined spring damper units like FJ/F3 etc in period. Am not sure how I get my phone details to you without publishing them to the world on this forum. If you have links with HSCC ask Alan or Grahame to put us in touch.
In the long lost past did you have family TVR connections? If so is Peter still around?
#31
Posted 05 December 2010 - 17:27
You can also e mail through my web page www.setfordracing.co.uk
There is an e mail link there
Thanks
#32
Posted 07 December 2010 - 15:50
#33
Posted 27 January 2011 - 05:41
Hi Dimsodan. Not sure if you have been able to discover the identity of your Lotus 7 yet, but there are a couple of ways that may determine authenticity and chassis manufacturer. Looking at your photos, it appears to be a Series 2 Lotus Seven chassis. These were produced by 2 manufacturers for Lotus - Arch Motors and Universal Radiator. The difference between the 2 manufacturers was their tube frame joining process. Arch motors used (and still do) gas flux braze welding (a process approved by Colin Chapman for speed of construction, ease of repair and cheapness), on the Seven and a number of Lotus racing cars that used space frame technology. The tubes will have a bronze coloured fillet where they are joined. Universal on the other hand fusion welded their Seven chassis (most likely using oxy-acetylene equipment back then). The fillets will be of the same colour as the bare metal. Each manufacturer identified their particular chassis with their own letters and numbering system. Arch Motors punched letters and numbers on or in the vicinity of the angle bracket where the brake and clutch master cylinders attach to, with 'AM' followed by four numbers e.g. AMXXXX. Universal did the same thing in the same place, but their chassis are lettered 'B' followed by four letters. If the chassis is left hand drive, Universal indicated this by using 'BLXXXX' instead of 'BXXXX' (as per their r.h.d chassis). The actual vehicle serial number was engraved on an aluminium Lotus works plate and may contain the engine serial number as well (it didn't however on my car!). This plate is normally attached to the flat aluminium sheet below the windshield scuttle. It originally consisted of the letters 'SB' followed by 4 numbers ('SBXXXX'). Lotus later decided to identify the l.h.d. cars with an 'L' before the 'SB, thus 'LSBXXXX'. John Watson of the Lotus Seven Register is an excellent source of knowledge regarding the authenticity of Lotus Sevens. Although your chassis looks authentic - i.e. correct tubes and fittings in correct places, any one of the owners could have had it modified to I.R.S. for racing purposes by any fabricating company familiar with the 7, or had it performed possibly through the factory. The Lotus Seven Series 3 used the same chassis design, with a few extra brackets fitted for a new type of exhaust and for seat belt mounts. When the Series 2 chassis were used up and the decision was made to fit the twin-cam to 13 (or more?) Sevens, these and later chassis were further triangulated to handle the extra bhp. Of all the Lotus Seven chassis manufactured (i.e. not including Caterham versions), the Series 1 was probably the best and strongest, but due to production costs, Mr. Chapman took away tubes on the Series 2 and relied heavily on the aluminium body cladding to take the stresses. Many owners of Series 2s and 3s report the same common failures to their chassis. This is one of the reasons why the Seven SS was strengthened and Caterham took the strengthening much more seriously on their versions of the Seven. Some Lotus Seven owners seeking authenticity feel that it is sacrilege to alter the Lotus designed chassis, others wanting a car that doesn't break chassis tubes and joints go for the extra triangulation and consequential extra weight. You pays your money etc..... Hope this helps.
Edited by Spaceframe7, 27 January 2011 - 05:44.
#34
Posted 27 January 2011 - 08:16
Low drag - on a Seven!
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What next?
Ashtrays on a Triumph Bonneville?
Carbon fibre panels on an ERA?
3.8 litre engine in a C-Type
IRS on a D-Type
FPF in an Elite
FPE in an Eleven
Fibreglass body on a Seven (whoops ! I forgot about the Series 4)
Duncan
David Buxton put a 2 litre FPF in an Elite in period. I never saw it race as the car would not stay together for long enough to get it past practice. But I did see it practice and it looked and sounded pretty terrifying
John
Edited by Sharman, 27 January 2011 - 08:17.
#35
Posted 27 January 2011 - 10:11
The post was intended to be ironic. Apart from the ashtrays on a motor cycle, I think they have all been done by people "restoring" historic cars to make them go better. But, as they are no longer authentic I feel it defeats the object of racing a historic car.Duncan
David Buxton put a 2 litre FPF in an Elite in period. I never saw it race as the car would not stay together for long enough to get it past practice. But I did see it practice and it looked and sounded pretty terrifying
John
#36
Posted 27 January 2011 - 10:43
The post was intended to be ironic. Apart from the ashtrays on a motor cycle, I think they have all been done by people "restoring" historic cars to make them go better. But, as they are no longer authentic I feel it defeats the object of racing a historic car.
Well aware of the irony but I was just pointing out that it was, in the case of an Elite, done in period rather than by modern upgraders. My pet hate is FJ cars of 1959/60 with 130 bhp engines. An Elva 100 was lucky if there were 65 BMC gee-gees against 85 Italian stallions in the Stangs etc.
#37
Posted 27 January 2011 - 14:07
This plate is normally attached to the flat aluminium sheet below the windshield scuttle. It originally consisted of the letters 'SB' followed by 4 numbers ('SBXXXX'). Lotus later decided to identify the l.h.d. cars with an 'L' before the 'SB, thus 'LSBXXXX'.
Slightly O/T - does "SB" stand for self-build??
#38
Posted 27 January 2011 - 16:08
Duncan
David Buxton put a 2 litre FPF in an Elite in period. I never saw it race as the car would not stay together for long enough to get it past practice. But I did see it practice and it looked and sounded pretty terrifying
John
It also roasted Innes Irelands feet in pactice at LeMans in 1960 . An evil disaster of a car !
#39
Posted 27 January 2011 - 21:44
Slightly O/T - does "SB" stand for self-build??
Hi, Maybe they should have reserved 'SD' for 'self destruct'?. Originally of course, self-build is what the car was designed to be to avoid the then British taxes - more smart business acumen on the part of Mr. Chapman. According to Jeremy Coulter in his book "The Lotus and Caterham Sevens" in his chapter on Chassis number sequences, he wrote that for the Series 2, "All cars had prefix SB for Series B, left-hand drive cars with an additional L prefix". He then writes that the Series 3 Lotus Seven had serial numbers from SC2311 - 2563, with SC2564-2576 assigned to cars fitted with the Lotus Twin Cam engine. I believe (until advised differently) that this is an error as this numbering system i.e. 'SC', is correct only for the Twin-Cam cars. Checking the Lotus 7 listings on the excellent U.S. "Simple Sevens" web site (currently shut down under redesign), of all the Series 3 cars listed - and there are quite a number of them - they all had SB (and LSB) serial numbers, none had SC. Not sure where Mr.Coulter obtained his information from regarding this, but the book is very good. Further, it has been documented that the early Series 2 Sevens that were imported to the U.S. all had SB serial numbers, but at least a few of them must have been l.h.d. It has also been noted that Lotus was quite lax in assigning serial numbers to the Seven (and perhaps other models?). In the Seven serial number sequences, Lotus Elevens, Fifteens and Formula Juniors were included in the mix prior to the SB or LSB designation being added. Maybe it kept the tax man hopping?
One other note pertaining to the original question that started this post, (relating to the I.R.S. design added on to the rear of the chassis in question) even though Arch and Universal Radiators produced the basic Seven chassis for Lotus, the factory naturally experimented with these constructed chassis to make improvements. One ex Lotus employee who I have been fortunate to be in contact with, advised that as a mechanic working on the Lotus Seven production line (Series 2, 3, and 4), he learned how to weld at the Lotus factory by experimenting on fully built Seven chassis. He was involved with alterations to the steering rack height of later Series 3 chassis, then began working on the Series 4 project. He went on to work on the 7X, and then Formula 1. Dimsodan's chassis could have been Lotus factory produced, by Arch Motors, or by a racing firm. Either way, it looks very professional and fairly authentic, as Lotus did build a few replicas of the '7 1/2' or 7/20 as it was known for non-works drivers. Also to answer another post, there was only one 7X constructed. This car was partly based on a Series 4 with a few Series 3 bits welded on to the rear. Lotus Factory I.R.S. models were the 7 1/2 or 7/20, 37, and 7X. A few Series 1 cars were equipped with De-Dion rear end, but I cannot find any record of any being equipped with I.R.S. Dimsodan's car is a bit of a mix of Series 2, 3 and Caterham, so to be truly accurate he may need to search for authentic parts. EW
Edited by Spaceframe7, 27 January 2011 - 22:12.
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#40
Posted 27 January 2011 - 22:46
to avoid the then British taxes - more smart business acumen on the part of Mr. Chapman.
But perhaps more accurately credited to the original idea and connections of, and lobbying by, John Bolster of Autosport, in Parliament.
Roger Lund
#41
Posted 28 January 2011 - 03:08
But perhaps more accurately credited to the original idea and connections of, and lobbying by, John Bolster of Autosport, in Parliament.
Roger Lund
I naturally defer to your knowledge on this, but I wonder why more manufacturers other than Lotus didn't jump on the bandwagon and sell D.I.Y cars, or did Mr. Bolster lobby solely for Lotus? In this day and age, there are dozens of 'kit car' manufacturers about. In the late 50s and early 60s perhaps there were only a handful - if that - of car companies able to produce construct-it-yourself cars suitable for the road, and take advantage of a legal 'loophole' thus avoiding extra taxation. Mr. Chapman jumped at this opportunity as an astute businessman. Unfortunately none of the books in my very limited Lotus library give any credit to Mr. Bolster, when it sounds like they should have. Thank you for putting the record straight Roger. EW
#42
Posted 28 January 2011 - 08:22
Ginetta Marcos Tornado TVR plus inummerable other marques went down the "home assembly" route, it was endemic in the 50s and 60s. Lotus were not alone as spaceframe seems to suggest and I doubt they were the first. Must admit I didn't know about JVB's involvement Roger, can you source that for me?
John
Edited by Sharman, 28 January 2011 - 08:23.
#43
Posted 28 January 2011 - 09:13
Where do we start
Ginetta Marcos Tornado TVR plus inummerable other marques went down the "home assembly" route, it was endemic in the 50s and 60s. Lotus were not alone as spaceframe seems to suggest and I doubt they were the first. Must admit I didn't know about JVB's involvement Roger, can you source that for me?
John
Autosport reported it fully IIRC.
RL
#44
Posted 28 January 2011 - 09:55
Must have missed that, I only ever read the race reports and the small print. Big words like marmalade and corrugated used to confuse me.Autosport reported it fully IIRC.
RL
#45
Posted 28 January 2011 - 20:25
Also, in regards to spaceframe kits, Buckler were supposedly the first to market a spaceframe DIY sports car.
#46
Posted 28 January 2011 - 23:02
Where do we start
Ginetta Marcos Tornado TVR plus inummerable other marques went down the "home assembly" route, it was endemic in the 50s and 60s. Lotus were not alone as spaceframe seems to suggest and I doubt they were the first. Must admit I didn't know about JVB's involvement Roger, can you source that for me?
John
I don't think that my post suggested anywhere that Lotus were alone in going this route. I mentioned a 'handful' and the four you mention is a good start. Not sure why Colin Chapman cannot be given some credit for his business acumen - his company has kept going through rough and smooth, where others have folded completely.
#47
Posted 29 January 2011 - 08:37
You did ask why other manufacturers did not sell "home assembly" kits. You went on to say that there are dozens of present day kit car on sale and implied that is was a modern phenomena. All I said was that the condition existed in the 50s and 60s. As has been pointed out in another post Derek Buckler was offering chassis and body options and may have been the pioneer, there really were a lot of people at it before ACBC jumped on the bandwagon.I don't think that my post suggested anywhere that Lotus were alone in going this route. I mentioned a 'handful' and the four you mention is a good start. Not sure why Colin Chapman cannot be given some credit for his business acumen - his company has kept going through rough and smooth, where others have folded completely.
#48
Posted 29 January 2011 - 13:32
Edited by Bloggsworth, 29 January 2011 - 13:32.
#49
Posted 29 January 2011 - 19:09
http://www.1950sspecials.com/home.htm
I believe Mr Chapman's business acumen was in part his ability to recognise other peoples great ideas and refine them and incorporate them into his own designs .
Unfortunately he has tended to be credited with their ideas as well , whether this was also part of his business acumen , or historical mythology ?
I'm sure there are members of this forum who can enlighten us to the facts ?
#50
Posted 29 January 2011 - 21:50
A very nice site covering the 50's Kit car phenomenon -
http://www.1950sspecials.com/home.htm
I believe Mr Chapman's business acumen was in part his ability to recognise other peoples great ideas and refine them and incorporate them into his own designs .
Unfortunately he has tended to be credited with their ideas as well , whether this was also part of his business acumen , or historical mythology ?
I'm sure there are members of this forum who can enlighten us to the facts ?
Don't believe, know before you make statements like that.