SU kickdown linkages? (efi-carb conversion on auto)

paul c · Post by **paul c** » Tue May 26, 2009 8:48 am

The linkages were available on 86-91RR, but are obsolete new, only one arm is still available, I converted my 3.9 auto to carbs and was unable to find all the parts. LDV autos also used them, probably more common in the UK than carbed RRs. Basically you need to operate the kickdown from the carb rather than the throttle as the can doesnt give the correct opening of the throttle as the kickdown if that mekes sense.

Grant · Post by **Grant** » Thu May 28, 2009 8:55 am

this is it!

Dated '73 so must be from a P6...

ChrisJC · Post by **ChrisJC** » Thu May 28, 2009 10:06 am

Looks to be very suitable for a small mod.....

Chris.

harvey · Post by **harvey** » Thu May 28, 2009 1:29 pm

You need to take the picture from a bit further back to show the rear of the manifold, but, that isn't a P6B throttle set up, and it actually looks like a HS6 manifold, with HIF6 carbs on it, with a manual SD1 throttle return spring and bracket.

Has it got two threaded (5/16 UNC) holes in the rear facing forward by no7 cyl?

Grant · Post by **Grant** » Thu May 28, 2009 2:26 pm

Hiya...

It has 8.3.73 stamped on the top of the manifold

harvey · Post by **harvey** » Thu May 28, 2009 2:40 pm

That picture confirms it as P6B (HIF6) or possibly early P6B, or P5B (HS6) the difference being the height of the step up in the casting on the top of the manifold parallel to where the throttle link bushes are cast in.

It's a mix and match of loads of bits all of different eras. The dashpots on the carbs should tell you whether they are P6B or SD1, but they're not quite in the picture enough to be sure.

Grant · Post by **Grant** » Thu May 28, 2009 2:52 pm

Take 3, da daaa...

Cheers guys

harvey · Post by **harvey** » Thu May 28, 2009 3:08 pm

Wish I could post pics. You're waaay in front of me on that!

Right, those are SD1 dashpots so one would assume that they are SD1 carbs. That being the case they should have poppet valves on the butterflies which want soldering shut or replacing with plain ones.

But it still looks like a HS6 manifold, because if the height of the step in the middle which is causing the need for the bend in the choke link.

Grant · Post by **Grant** » Mon Jun 01, 2009 8:58 pm

Just for the record- I think this is what the kickdown bracket looks like!

Just bought a holley 390/offenhauser though- sorry about that fellas!

harvey · Post by **harvey** » Mon Jun 01, 2009 9:17 pm

Yep, that's the SD1 type kickdown bracket, retained by the two bolts into the bosses on the rear of the manifold. (Those bosses being absent on the P6B manifold which has a different set up because of that.)

And after all that, you wont be using either.....