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

Grant · Post by **Grant** » Wed May 20, 2009 7:58 pm

Hi, I'm hoping to convert my '87 rangie from its flapper efi to carb/s. Trouble is, its an automatic and none of the SU carbs I see for sale seem to have to kickdown linkage I see in the haynes manual

Is there a simple way to knock something up for this or can you still get the linkages new from somewhere?

Tried getting a used Holley/Weber kit but had no luck at all- computer crashed before bidding the other day, paypalled for a carb which was already sold today (got it back)... I'm thinking a higher force doesn't want it to happen!

The efi was overfuelling to the drivers bank, revving too high & I'm scared of chucking expensive bits at it- thats the reason anyway

cheers!

ChrisJC · Post by **ChrisJC** » Wed May 20, 2009 8:50 pm

The autoboxes fitted to SU carb SD1's are vac operated kickdown as far as I know.

However, I knocked up a linkage very distantly based on the EFi kickdown linkage (& some angle iron!):

Chris.

Grant · Post by **Grant** » Wed May 20, 2009 10:30 pm

Nice work, cheers for that.

I'll have to have a look at mine to work out what exactly is going on there!

ChrisJC · Post by **ChrisJC** » Thu May 21, 2009 6:59 am

Yes, it's not too clear is it!

Basically I used part of the EFi stuff to extend the spindle that rotates when the throttle cable is pulled. Then I welded an arm onto the spindle that hangs down below (which you can't really see), which pulls the kickdown cable. I also added an extra return spring which hides the arm in the photos.

It took a fair bit of faffing to get the motions all working properly.

Seems to work OK though! And it's very low profile as I have coil packs sat above it.

Chris.

Grant · Post by **Grant** » Thu May 21, 2009 8:31 am

Ahh I'm beginning to see what you did there... you haven't got a few more pics on your computer have you?

This is a proper result to find someone else who's done exactly the same thing I want to do, cheers!

ChrisJC · Post by **ChrisJC** » Thu May 21, 2009 9:49 am

I haven't I'm afraid. The best I can do is zoom in to get the full detail on the ones I have. And now it's buried under coil packs, carburettor trunking etc, so it's very hard to see it at all!

I will look into it though.

Chris.

Grant · Post by **Grant** » Thu May 21, 2009 10:40 am

Ah, don't worry about it... I'm guessing its one of those things that becomes clear once you have everything there. Just need to grab a pair of carbs of ebay and a regulator to get the pressure down to 5/6psi isn't it?

thanks

harvey · Post by **harvey** » Thu May 21, 2009 2:06 pm

ChrisJC wrote:The autoboxes fitted to SU carb SD1's are vac operated kickdown as far as I know.

Not true, vac operation came in on the GM180, all the previous BW65/66 from the start in '76 to 1982 had cables. You shouldn't have any problem finding either the bracket for the SD1 SU set up, or the P6B bracket used with HIF6's. IIRC the P6B bracket will fit with the SD1 manifold, but not the other way round.

Grant · Post by **Grant** » Thu May 21, 2009 7:26 pm

What is it... I see decent looking SU's going for 25-40, I bid over the usual price and then I still get outbid at 60! Do my bids smell or something?

Hi harvey... any ideas where I could get a bracket? I've checked rimmers but they don't list any on their site. not really up on SD1's to be honest.

*right, got SU's & manifold (for 26). might have to rebuild them, see how it goes...

harvey · Post by **harvey** » Thu May 21, 2009 10:05 pm

Grant wrote:Hi harvey... any ideas where I could get a bracket? I've checked rimmers but they don't list any on their site. not really up on SD1's to be honest.

I had a look on Rimmers and couldn't find them either.

You may buy a manifold with the bracket on already, or with it, if not when you get one take a pic of where the bracket goes on the manifold, and I'll see what I've got.

Grant · Post by **Grant** » Sun May 24, 2009 9:22 am

Hi cheers Harvey

Just looked in my haynes and I think I might have bought carbs with some sort of auto linkage by chance! Sort of X shaped with 2 rods overlapping each other from opposite corners?

I think its from an SD1

Just have to see what turns up in the post!

ChrisJC · Post by **ChrisJC** » Sun May 24, 2009 9:26 am

If it's two linkages between the two carbs, one will be throttle, the other choke.....

Chris.

Grant · Post by **Grant** » Mon May 25, 2009 10:58 am

Hi Chris. its difficult to describe but these are the haynes RR pics...

manual box-

auto-

I don't really know what I've bought though because the pic in the advert was overhead so I can't see the linkage that well (think its the X-shape) and the seller didn't know which gearbox the car they came from had!

ChrisJC · Post by **ChrisJC** » Mon May 25, 2009 11:19 am

I think I would go along with the idea that the lower picture is what you need......

Chris.

harvey · Post by **harvey** » Mon May 25, 2009 6:12 pm

There's no kickdown linkage on either of those pictues, because it doesn't fit to the carbs, but to the linkage. If you look at pic1 the kickdown linkage would be fitted where the return spring is, and back towards you as you look at it.

As said earlier, they are only the throttle and choke links between the carbs.

A picture taken from the rear, (like those) and showing the rear corner of the manifold (by no.7 cyl) will show what type of manifold you have, and hence what type of bracket you can use.