Jarama Tyres - a bit of research into originality - can you help? | LamborghiniChat
News

Jarama Tyres - a bit of research into originality - can you help?

Discussion in 'Lamborghini Front-Engined' started by Longstone Tyres, Jan 22, 2020.

  1. Longstone Tyres

    Longstone Tyres Karting

    Feb 2, 2006
    111
    Full Name:
    Dougal
    Hi

    I have just been in contact with a dealer who amazingly had 2 Jarama in stock, which i was very impressed by.

    It drove the question as to why i hadn't built a page about the Lamborghini Jarama, where i have covered the other Classic Lambos https://www.longstonetyres.co.uk/classic-car-tyres/lamborghini.html

    So i want to get my page as accurate as possible so:-

    when looking at the the Jarama it seems there have been 3 models
    • Jarama 350 GT (maybe 1970 - 1972) now i think this car fitted 205VR15 Cinturato CN72, at least untill some point in 1971. i think t hat because the Cinturato CN12 was not invented untill 1971 (i have also had suggestions that they came out in 1972, but Pirelli say 1971)
    • Jarama 400 GT 2 + 2. So 215/70VR15 Cinturato CN12. there is a great picture of old Feruccio leaning on a Jarama fitted with the CN12
    • Then i think there is a Jarama S (1973 - 1976) which i beleive also fitted 215/70VR15 CN12. (this car might also be called a Jarama GTS)
    My tyre pressure books make me think that they ran 35psi front and 38psi rear.
    then the Jarama S (or GTS ) 36psi front and 41psi rear.

    I realise that for some years the Pirelli wasn't produced, so most cars untill a few years ago will be fitting Michelin XWX, which of course is also a good tyre.

    If anyone knows any more or can correct my thoughts please let me know. Also any pictures that back up our research would be very greatfully appreciated.
     
  2. Peter K.

    Peter K. F1 Rookie

    Jan 9, 2004
    3,962
    Connecticut
    Full Name:
    Peter K.
    Olivier will be able to give you confirmation.
     
  3. miurasv

    miurasv Formula 3

    Nov 19, 2008
    1,118
    Cardiff, UK
    Full Name:
    Steven Robertson
    #3 miurasv, Jan 27, 2020
    Last edited: Jan 27, 2020
    There was no Jarama 350 GT, just the original GT, which produced a claimed 350 BHP, the figure of which is what you could be confusing, and the later GTS, also known as Jarama S, which produced a claimed 365 BHP. Both models had the 3929 cc engine.
     
  4. Longstone Tyres

    Longstone Tyres Karting

    Feb 2, 2006
    111
    Full Name:
    Dougal
    I wondered.

    I did see a reference for a Jamara 350 GT, but only in one book or on one web site, but can't find it now.
     
  5. miurasv

    miurasv Formula 3

    Nov 19, 2008
    1,118
    Cardiff, UK
    Full Name:
    Steven Robertson
    #5 miurasv, Jan 28, 2020
    Last edited: Jan 28, 2020
    The Jarama models were only ever the 400 GT and the 400 GTS. Only the first Lamborghinis V12s were 350s such as the show protototype 350 GTV, which actually had no engine, and 350 GT that went into production that was subsequently replaced by the 400 GT.
     
    Olivier NAMECHE likes this.
  6. miurasv

    miurasv Formula 3

    Nov 19, 2008
    1,118
    Cardiff, UK
    Full Name:
    Steven Robertson
    #6 miurasv, Jan 29, 2020
    Last edited: Jan 29, 2020
    The Jarama would always have been on low profile tyres due to the period introduced, whereas the Miura and Espada would have had full section 80 aspect ratio tyres when they were introduced, but received low profile tyres later. Low profile Pirelli Cinturato GR70 VR15 were used on the Jarama 400GT, which could well have been the HS CN12. Michelin XWXs may have also been used later on the Jarama 400 GTS in size 215 70 VR 15.
     
  7. Longstone Tyres

    Longstone Tyres Karting

    Feb 2, 2006
    111
    Full Name:
    Dougal
    Yep, that makes sense The CN12 came out in 1971, and that same 215/70VR15 CN12 was fitted to the front of the Muira SV https://www.longstonetyres.co.uk/catalog/product/view/id/5491/category/6441

    Then the SV fitted a larger rear 255/60R15 CN12 https://www.longstonetyres.co.uk/catalog/product/view/id/5363/category/6441 which at the time i think was the biggest tyre to be able to attain that speed rating.

    Pirelli did do an earlier low profile tyre in 1968 the CN36 https://www.longstonetyres.co.uk/pirelli-collezione/cinturato-cn36.html However we hope that that wasn't what they fitted, because Pirelli do actually make a 215/70VR15 CN12 now, but they don't make a CN36 in that size.

    Do you have any thoughts on tyre pressure?

    Are there any good period pictures?

    Do you know if Lamborghini did actuall fit XWX?
     
  8. miurasv

    miurasv Formula 3

    Nov 19, 2008
    1,118
    Cardiff, UK
    Full Name:
    Steven Robertson
    #8 miurasv, Jan 30, 2020
    Last edited: Jan 30, 2020
    Thinking about it, the Pirelli GR70 VR15 tyre would have been the CN73 as used on the Miura P400S. The Miura P400SV had front HS CN12 in size 215/70 x 15, but I'm quite sure the fronts were marked FR70 VR15 and rear 255/60 x 15 tyres marked HR60 VR15. Also, the Jarama came out in 1970, but the HS CN12 tyre didn't come out until 1971, as you said, so initially could not have used this tyre.

    Lamborghini were definitely using Michelin XWX for the LP400 Countach, 205 70 VR14 by 1974 so may well also have used the Michelin XWX in 215/70 VR15 on the Jarama S, and the Espada S3 which had the same wheels by this time.

    I don't know anything about the pressures.

    What is the difference between a Pirelli HS CN 72 and HS CN 73?

    We need someone with the Jarama and Jarama S Owner's Manuals to see what they say about the tyres.
     
    Olivier NAMECHE likes this.
  9. AndyUK

    AndyUK Rookie

    Jun 11, 2020
    5
    Full Name:
    Andy May
    This thread is a little old, but I will add the information I know about in case it is still of interest:

    For 1970, at least the first UK car was fitted with Michelin XWX 215-70VR 15's from the factory. This is well documented in "Motor" magazines road test of ELB420J published July 1971. At the time of the test the car had accumulated 8000 miles, so I feel its fairly safe to say the tyres were those originally fitted.

    When I purchased the car, it had one of those XWX Michelins still as the spare and was shod with Pirelli Cinturato CN12 215-70VR15's. When I came to replacing the CN12's during the cars refurbishment, I chose to fit Pirelli P600 235-60 15's. I was not particularly a fan of the look of the Michelin XWX on the car as they looked a little "lost" within the wheel arches. I did consider the re-released 215 CN12's, but from the specifications on Longstone's website they do seem quite a bit undersized compared with the (probably ~30 year old) originals on my car. The P600's were a good compromise.

    Some photos to illustrate:

    Pirelli Cinturato CN12 compared to Michelin XWX (both tyres original spec) - I didn't like the "look" of the Michelin on the car:

    Image Unavailable, Please Login

    Photos measuring the "old" style 215 CN12:

    240mm Actual Width (compared to 223mm of the "New" CN12 on Longstone site) - I probably should have discussed this with Longstone first, but chose the P600 as it seemed to be almost the same dimensions as my old CN12.

    Image Unavailable, Please Login

    The P600 compared to the old CN12: Almost the same dimensions

    Image Unavailable, Please Login
    Image Unavailable, Please Login

    I hope that has been of interest.

    Kind regards

    Andy May
     
  10. Longstone Tyres

    Longstone Tyres Karting

    Feb 2, 2006
    111
    Full Name:
    Dougal
    Oo Andy, sorry, but i think you have made a mistake.

    The materials in your old tyre have relaxed the tyre has stretched. tyres do get fatter as they get older often. specially tyres from those days. Which is also probably why the old CN12 also looks taller than the P600

    The current Pirelli Collezione tyres are built to the same dimensions as they were in period. The current CN12 are correct.

    I'm afraid i think you have made a mistake. This P600 look completely wrong, that side wall looks so garish compared to anything that was around in the 1970s. The P600 from memory is late 1980s (i think '87). The P600 certainly won't drive as nicely on your car as the CN12. They are designed for a much later chassis.

    have you driven on them yet? maybe i can swap them for you. please get in contact. https://www.longstonetyres.co.uk/classic-tyres.html we'll do what we can if they haven't been driven on.
     
  11. AndyUK

    AndyUK Rookie

    Jun 11, 2020
    5
    Full Name:
    Andy May
    Hi Dougal,

    It is indeed possible that my CN12's are so old they have mis-shapen (it seems a huge dimensional change to me though). However, I really like both the look and the driving of the P600's on my car so will definitely be keeping them. Thank you for your advice though - it sincerely appreciated.

    I hope the historical aspect of my post was of interest to you.

    Kind regards

    Andy
     
  12. Longstone Tyres

    Longstone Tyres Karting

    Feb 2, 2006
    111
    Full Name:
    Dougal
  13. Olivier NAMECHE

    Olivier NAMECHE F1 Rookie

    Aug 18, 2007
    4,453
    CANADA
    Full Name:
    Olivier
    Hi Dougal

    here are the owner's manual pages... as you can notice , tires pages are identical... as almost the content of the book.

    400 GT has claimed 350 hp/din

    400 GTS has claimed 365 hp/din

    both engines are identical, none difference, only donkeys figures for the litterature...
     

    Attached Files:

  14. Longstone Tyres

    Longstone Tyres Karting

    Feb 2, 2006
    111
    Full Name:
    Dougal
    Hi

    that is ace thank you for that.

    Correct me if i'm wrong, but that litereature was printed early, before they changed to Pirelli CN12? I think pre 1973.

    I have come accross early XWX tyres simply being called an X. but i would suggest they look just the same.
     
  15. Olivier NAMECHE

    Olivier NAMECHE F1 Rookie

    Aug 18, 2007
    4,453
    CANADA
    Full Name:
    Olivier

Share This Page