729 replies to this topic

[claysummers]

You’re in a good position there, Clay
Should be able to make a real good set out of those two
We can try the TW needles in your motor that I have
maybe I could swap for the RHs seeing as I buggered mine up
trying to mess with ‘em..

What sort of linkage mountings do you have on the first set with
the trumpets on?

Thanks for the offer to swap needles mate. See if I can pull down the others, see what they are, tomorrow.


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[warrenm]

I'll get some pics tomorrow for the shaft mounts.

[claysummers]

That’d be handy thanks Warren.

Where for gaskets? Minisport online looks ok. Looks like a set includes the piston bumper. Mini Moke ffs.


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[warrenm]

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This setup is on my 2" SU's, but was fitted to the 1 3/4. It's made from 40mm x 3mm angle & fitted to the manifold flange with bolts going through the carb & manifold flange.

The spring loaded needles in your carbs are a pain to work with, much easier to convert them to the .100" fixed needles  0100-fixed.png   7.33K   12 downloads

, need access to a lathe to make some bushes to go in the pistons. The secret to su's is make sure the throttle shafts aren't sloppy, which can be repaired by using solder on the shafts, then file & polish(in a drill) to fit the body, & don't try to have the idle too low, a lot of people set the idle at 500 or 600revs like a std engine, set it 700 or 800, you'll have less problem with stalling. 

SU Midel for spare parts in NSW.

As for needles, I'd start at OA7, I've always found RH far too rich.

[claysummers]

Thanks. Yes the shafts appear to be nizeantite. Yes Bruiser IDd the needles rich. Have another set to pull down so I will see what needles are in them.


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[warrenm]

Buy these from Midels, bushes to convert the spring loaded needles to fixed.  https://www.sumidel....su-needle-parts

[claysummers]

I’m missing one retainer clip on the brass linkage rod end, so on the hunt.

Thanks for tip on the idle.


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[claysummers]

Was a bit concerned when one needle was loose, and nearly lost the spring on the floor, so those look the go. Minisport looked considerably cheaper for gasket set though (tightarse).


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[claysummers]

Pulled down the other set I got with the warnerford design manifold. Two out of three have the fixed needle setup by the look. OA6 needles but the one that hasn’t been converted looks like it may have had some grief. Looks slightly bent but may just be the collet which comes off for the fixed conversion anyway?


It doesn’t seem like the pistons are matched to the carb bodies as they are a loose fit. Can anyone confirm please? I know the pistons and domes are matched sets.


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[Bruiser]

Is there any wear in the domes or pistons where they slide against each other?

Do you have three of the solid non - spring loaded needle bushes out of the 6 you have?
The TWs here are for solid mounting
Not sure if solid needled can be used in the spring loaded setup,
I popped the spring collar off a set of nice fat lean BBF needled to have
a go at lathing them down to suit and they had a knurled section at the top
where the spring collar presses on. Needed to file it down to fit in the solid bush.
OA6 will be too rich for your motor too, might be great in mine, though
CanI buy/trade them too if you have no plans for them?

[claysummers]

Happy to trade mate. I’ll have a closer look at the piston to cup wear but initial inspection looks all good. One of the pistons on the second set was very slightly bound up in the cup when I pulled it. Same one the needle fell out of.

The one that fell out is spring and collar and the other two are friction bush retainer, so I need one mor bush per Warrens link to su midel. The other set are all collar and spring.


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[claysummers]

Where was I?

Not sure wht thread these are. I would like some longer ones to mount 3mm plate for the linkages.
Tried 3/8bsp was close ut bit tight.

One of the float bowls was fouled with white powdery residue crystallising around the jet outlet so in the ultrasonic bath.
I tried kerosene previously to little effect so using 91 fuel. Heat to 50C and run 30 minutes. Feels suss using fuel but works pretty well.

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Edited by claysummers, 17 June 2023 - 11:33 PM.

[claysummers]

The fuel lines on the jets appear brittle. I wonder if these can be replaced, or buy new jets at $44 each.


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[I'm a Red Motor fiend]

Buy 3 new .100" jet tubes and run the fixed needles.
I haven't got much more to add as Warren and Bruce have this covered.
My linkage setup is the same as Warrens, I suggest you should look to do something similar, not as proposed above.

I think you mentioned the throttle shafts have some play? If not rectified it will be hard to get these to idle properly.

I would also do away with the choke setups too. For a non daily driver it's just more stuff to fiddle around with. On cold start the good old clothes peg works wonders with the jet pulled down. I've never run chokes on SU's.

I would definitely run a fuel reg also.

[claysummers]

Ok thanks Adam. Yes to new jets and fixed needles. Throttle shafts are very good on the set I am using. Other set were crook.

I am using a different manifold for firewall clearence and most of the flange bolt holes dont run through, they are blind.This is the geometry I need.More thought required.

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[claysummers]

May just choke the back or middle one per Bruiser.

Below maybe why there are a lot of sets either opposite fuel bowl.
May need shielding.

Only one of the top flange bolt holes is usable.

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[I'm a Red Motor fiend]

Ok, sounds like you have a good set on the cards.
This linkage thing is difficult.

Do you plan to run vacuum advance and pcv?

[Bruiser]

Are those top three holes the blind ones? The rearmost one is what I would expect to be for your brake booster, the fitting there looks like one too.
The cross brace they are drilled in must be hollow, I assume all those type of manifolds have open connections between runners for the balance pipe setup. Your armours have tapped holes to put your own flex hose between each one

.  E9BBFE18-C531-4096-8FEA-540C1A9707CF.png   35.57K   9 downloads

I have these on mine to mount the 3 rosejointed pedestals for the hex bar.
It looks like Warren has made his own nifty set in his picture, the black ones.
Same idea. The mount on the front of each carb using the top 2 of the 4 carb stud mounts.
Thanks for the needles too 👌

[Bruiser]

 570AAA14-1D13-4E6F-AAD2-8B7131BA091F.jpeg   235K   11 downloads

Just a like a dis

[claysummers]

Thanks Bruce. Talking about the flange holes not the vacuum ports. Warren's linkage mounts off the back of the manifold but I can do as you have off the carb side. Wonder where I can get some plates Iike yours or I can make some up.

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[claysummers]

Will need to be offset to clear the vacuum ports though, which are hard up against the flanges.

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[Bruiser]

Ah carb mount flange holes. Gotcha. The only place I can find those brackets
Is “Revheads” search “su top support bracket” $28.65 each.

[warrenm]

I made my mounts, but had them mounted the same as the pics that Bruiser put up originally, I had to change when I used the Armours manifolds instead of the Lynx.

[claysummers]

Thanks fellas, that is the go. I'll prolly make some up from 2mm scrap.

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[klevliend]

I've also got the same style linkage kit, mines a touch loose though, and the pedestals are tapped directly into the manifold which is less than ideal.
Eventually I'm aiming to replace all the linkages and use a bracket off the carb like you are. I wondering though, what are people's thoughts on the more expensive billet style arms? Are they worth the extra expense or just a bit of unnecessary flashy kit?

Can also say, I used one of the SU Midel conversions for the spring to fixed style needle. Was dead easy and very effective