Page 1 of 1

SC and carburetors

Posted: Wed Aug 03, 2016 8:27 pm
by keith fellowes
I am hoping that some well informed DDK'er may be able to help me.

I have an '81 SC with CIS and I want to put carburetors on it for historic rallying. The MSA have said I can't do that as it was homologated with CIS.
However they have a policy that if you can prove an item was 'used in period' then they will allow it and give historic papers.
The crux is that the proof has to be documented and not just anecdotal.

My question is, does anyone have any photos or articles of a 1977-1981 3 litre SC running carburetors?

Thanks

Re: SC and carburetors

Posted: Thu Aug 04, 2016 7:59 am
by hot66
No idea ... But every historical rally car I've see has been running carbs ( unless they have come I a 74-79 or similar class)

Re: SC and carburetors

Posted: Thu Aug 04, 2016 8:12 am
by dragonfly
Worth a call to Tuthills, as they have built a number of impact bumper rally cars?

Re: SC and carburetors

Posted: Thu Aug 04, 2016 8:47 am
by fetuhoe
The issue is quite subtle and difficult to resolve.

BHRC Cars which run with MSA Papers in Category 2 (Up to 31st December 1974) are known as Post Historic and all that is required to permit a modification is 'period proof' and it is well accepted that cars in this category can use Carbs and a waiver to use PMO variants was provided in around 2005.

If the car is run in this Category carbs are not an issue but the car must have been registered before 1/11975 or proof provided that it was manufactured before this date.

Cars of this type are normally run as a 3.0RS and scrutineering is quite lax with regard to body shape.

The issue is that a 1980 car, which is Category 3, must comply with its basic Homologation Form and none of the Porsche's of this date show carburettors as being homologated.

They are shown as having either a CIS or an MFI system.

In addition to complying with the relevant Homologation Form the car can be modified within the scope of the 1981 Appendix J - which clearly states that induction is 'free'.

However, the interpretation of 'free' is now taken to mean that it is a modification that must have been made 'in period' and some form of Documentary evidence must be supplied.

This is where the muddle begins to deepen.

In Belgium they commonly have a class that allows an 'MSA' spec car to run and many cars that run carbs are used on these events.

Scrutineering is again quite slack and the papers that these cars use may be quite old.

The MSA and the FIA are continually tightening up historic compliance and the issue is that until you apply for the HVIF you don't know it is will be accepted.

There was a time, a few years ago, when you could get a 'nod' before submission but recent structural changes within Historic rallying have made this quite difficult.

The 'safe' approach is to try to find proof that a 3.0 car ran on cars in this period or it could be a bit of a lottery.