Correct length of IRS lower control arm for S1

Talk about the E-Type Series 1
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jagwit
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#1 Correct length of IRS lower control arm for S1

Post by jagwit » Mon Jul 27, 2020 7:35 am

Helping a friend who bought an S1 in pieces and is re-assembling it now.

The car has so much negative camber at the rear, that the inside walls of the tyres are touching the bump stops. The amount of shimming required to correct it is so much that something is clearly wrong.

I suspect that the lower control arms are too long. I measure them at 313mm (12.32") as per the pic. Is this correct for S1?
Lower control arm length.jpg
Lower control arm length.jpg (57.06 KiB) Viewed 643 times
Best Regards
Philip
Jag: 72 E-type V12, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)

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Robbiee
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#2 Re: Correct length of IRS lower control arm for S1

Post by Robbiee » Mon Jul 27, 2020 8:07 am

Hi
That is the correct length
Have you considered whether the drive shafts are too short?
I believe that they come in different lengths
Mine are the early tubular ones so I’m not sure if that would help
Have you got the correct brake discs fitted?
Robbie 1962 3.8 Coupe OSG 1962 OTS ODG

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Bob.
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#3 Re: Correct length of IRS lower control arm for S1

Post by Bob. » Mon Jul 27, 2020 8:11 am

Hi Philip
The picture from the ROM shows dimensions for a S3 lower link. Rear track of S3 is 53.75", track of S1 is 50". AFAIK track increase of S3 was done by simply fitting longer bottom links and driveshaft from 420G. Leave you to do the sum to get dimension B for S1.

Image
Bob
'71 S3

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abowie
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#4 Re: Correct length of IRS lower control arm for S1

Post by abowie » Mon Jul 27, 2020 8:20 am

Robbiee wrote:
Mon Jul 27, 2020 8:07 am

Have you got the correct brake discs fitted?
That's where my money is.
Andrew.
881824, 1E21538. 889457..oops. Jezza the V12 XJS race car.
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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#5 Re: Correct length of IRS lower control arm for S1

Post by mgcjag » Mon Jul 27, 2020 8:56 am

Hi Philip..how are you checking the rear camber...what rear ride hight do you have.....Steve
Steve
1969 S2 2+2 & Building a C type replica

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jagwit
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#6 Re: Correct length of IRS lower control arm for S1

Post by jagwit » Mon Jul 27, 2020 9:19 am

Thank you Gents!!

Excellent input. I am presuming that the owner is reading the manual on how it should be done :roll:

I'll pass this on to the owner who is the one working on the car. At the time it did not occur to me that the drive shafts might be too short or that the brake discs might be too thin.

Bottom line, with a car that came in boxes, one can make NO assumptions. The quality of parts from the usuals are highly dubious. The car has not driven 400km yet and already the bushes are cracking / pulling loose.
Best Regards
Philip
Jag: 72 E-type V12, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)

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christopher storey
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#7 Re: Correct length of IRS lower control arm for S1

Post by christopher storey » Mon Jul 27, 2020 9:53 am

You do not mention tyre size. If, as is too often the case, an S1 is fitted with 205/70 rather than the correct 185 R 15 in either H or V rating, it is very common for the tyre to rub on the bump stops . It is simply a function of the tyre being too wide for the aperture

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#8 Re: Correct length of IRS lower control arm for S1

Post by jagwit » Mon Jul 27, 2020 10:05 am

christopher storey wrote:
Mon Jul 27, 2020 9:53 am
You do not mention tyre size. If, as is too often the case, an S1 is fitted with 205/70 rather than the correct 185 R 15 in either H or V rating, it is very common for the tyre to rub on the bump stops . It is simply a function of the tyre being too wide for the aperture
I can see that being the case. Good to know that!! Will let him know !

(I could have stepped into this trap with another friend's car that has tyres too small!!)
Best Regards
Philip
Jag: 72 E-type V12, 80 XJS (Megasquirt + 5sp manual O/D)
Jensen: 74 Interceptor (EFI by Megasquirt + O/D 4sp auto)
Chev: 59 Apache std, 70 C10 (350V8, 700R4)

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christopher storey
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#9 Re: Correct length of IRS lower control arm for S1

Post by christopher storey » Mon Jul 27, 2020 5:11 pm

Philip : another hazard of fitting 205/70s is that in some cars you cannot get the rear wheels off without deflating the tyre !

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