Finally a tidy 3500S!

Tor

Active Member
Been ages since I've been on here! Car has sat since summer, but today I feel I've turned a small corner - ordered two sets of bimetal strip assys from Burlen plus two BAF needles, the latter to follow Ron's advice of long ago. I've some seals kits waiting for the HIFs, so with luck I'll get the jets to adjust right, the mixture to work and the carbs to stop sweating and messing up my aftershave with petroleum-related fumes...

Next:
Brake booster sleeving courtesy Mark Gray so the car will stop better and not drag etc.
All new UJs, six of, to be fitted so the car might not vibrate all the time
Front top link bushes to be replaced (Metalastik) so it'll steer, not veer

It's a well known list of to-dos, but the hope is that it'll all happen this year.
 

Tor

Active Member
Hi all.

Got my brake booster fitted a while ago with the sleeved bore, and half of the funny behaviour is cured. But it still has notchy boost engagement, and disengagement delay, so I'll look at making the relief valve piston operate as smoothly as I can. Don't quite know how, though. I wish there were a workaround.

Changed the oil for Miller's Mini 20w50 today. The change was overdue and I didn't remember how the V8 simply dumps the oil in a matter of seconds the moment the bolt comes out, which resulted in my drain can getting a bit overwhelmed so now the drive is a mess. Look forward to seeing whether the new oil feels different. The old oil did smell a bit of fuel, which I hope is down to extended layups and short distances driven.

Apart from this I'm very happy to have her out and love the driving experience :D
 

SydneyRoverP6B

Well-Known Member
Staff member
Hi Tor,

Pleased to hear from you. :)

On the funny brake behaviour, the air control piston needs to actuate smoothly within the bore. Apart from removing the piston and ensuring that the seal is of the correct orientation, you can also install two modification springs woven together. This will increase the pressure applied to the aforementioned piston and assist in removing the disengagement delay.

Ron.
 
the secrets to cleaning up oil spills are 1) for indoors where you can't wash use (clean) kitty litter and 2) where youcan wash pour washing powder on it (leave some for the wife or you will be in the poo) leave for an hour and wash down. You can rub in in a bit first if you like. you can use the washing powder indoors too and sweep or vacuum (not with the house vacuum) it up.

going back to your needles, you really need to make sure the rest of the carby is in shape before worrying about needles, Speedpro publish an excellent book "the Su high performance manual" by Des Hammill. there is a specific section on Rover V8 needles
 

rockdemon

Administrator
Staff member
sorry i never spotted this the first time round. The program does work on theoretical airflow, but is an approximation which i think is on the rich side now having had feedback from a few people that have tried it. The factory needles are definitely lean for modern fuels but not by the amount the program suggests. Hopefully the BAF will be a better match. If you want graphs comparing needles let me know as i can get them for you.

Also you can check out minty lamb su compare-o-rama to get a view on needle strengths
 

Tor

Active Member
Thanks guys. Thankfully (for once), I have a gravel drive so I can sprinkle with sand (and washing powder, cheers for that)!

Hi Ron! A bit hesitant to risk a harder boost engagement, but I'll give it a whirl.

Rich, if your programme leans towards the overly rich, I think I'm safe as I've sports air cleaners in the canister..? I have new floats, bimetal strips and a seal kit waiting to go in so it'll end up being a light carb overhaul.
 

rockdemon

Administrator
Staff member
Yes i think it'll be fine. Mine runs best on KP, and if there was an in between needle it would actually like to be a smidgen richer.

Rich
 

Tor

Active Member
So, working on my HIF6s, I pulled out the needle jet bearing and after refitting it I noticed it remains recessed in the bridge by around 2 mm. The bearing has a sealing washer on it, and the locknut inside the float chamber sits proud. This doesn't seem to affect anything inside the float chamber.

image.jpeg image.jpeg

Reading in the WM how adjusting the mixture starts with the jet flush with the bridge (and then turning 2.5 turns CW), mine doesn't seem right. The jet doesn't seem impeded by the location of the bearing, but at full lean (adjuster fully CCW) it's still a smidgen below the edge. By gently pressing the nozzle against the bimetallic strip I can get it to protrude from the bridge. Am I not supposed to get it to protrude using the screw, or is this academic?

I have BAF needles going in, in case that makes a difference. Bimetal assy., float, needle valve assy. are new.

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The issue with my carbs was getting them both to respond similarly to adjustment of the mixture screw. The current one is the one that responded more or less as desired.

Also, the WM says the 'centre of the float ridge' should rest 1 mm below the edge of the chamber with the carb upside-down. The blessed thing has two ridges, one 1 mm below and one 1 mm above said edge.
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mrtask

Well-Known Member
Hi Tor
The red line in the image below indicates the orientation of your straight edge. You want to set the middle of the curved section (just out of shot, obscured by the leading edge of the float chamber) 1mm below your straight edge. It is easier with the jet removed, IIRC.


I'm sure somebody will be along to help you set the jets etc.
 

Tor

Active Member
Very cool, thanks!

What's more, I found the mismatch!
image.jpg
Even a non-engineer like me can see that won't add up. This is the side where I felt I couldn't get the mixture rich enough. Still, it does give me five full turns CW from flush. I'll have to call Burlen tomorrow!
 

Tor

Active Member
It turns out neither jet is the correct length. One is 69 mm overall and 40 mm from the nozzle/plastic down, one is 65/36 and they should be 66.5/38 according to Burlen. One carb has had work done or is a replacement, as all the gaskets were non-standard (and came off with little persuasion).
 

Tor

Active Member
Both carbs back together and going into the car as soon as it's less horrible outdoors. Burlen send me the wrong butterfly spindles, as the AUD521s fitted to the P6 have a particular length to them, so I will have to replace those another time. Everything else is now looking right and I'm no longer scared to open up one of these.
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Float chamber, needle and seat.
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Bimetal strip
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All in place. Trying to indicate the pin on the mixture adjuster screw with the screw driver. The tab on the float is not very well attached to the float body, as I found out.

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Choke spindle seal. I'll be keen to see how differently the engine behaves.
 

Tor

Active Member
For the first time in six years of ownership, it's good-bye lumpy idle! I've set up and adjusted everything from idle stop screws, fast idle and choke sync rod to mixture screws. Lift pins now briefly raise rpm. I have a stable 650 rpm at temperature. BAF needles have given me a tiny bit more low-end power and the improved settings give better engine braking too. Big improvement!

Two short clips:
 

mrtask

Well-Known Member
Well done that man.
S'good when it all works right, innit!?
Your old choke spindle seals aren't nearly as knackered as mine were!
Once you've had the carbs fully apart, the fear disappears.
Tor, I'm still looking for a pair of P6 headlight wiper assemblies, and the headlamp surrounds that go with 'em. Only ever offered on the P6 in your part of the world. Don't suppose you can help me track a pair down?
 

Tor

Active Member
Nice result! Your photos of the rebuild were spot on too.
Thanks!

Once you've had the carbs fully apart, the fear disappears.
Tor, I'm still looking for a pair of P6 headlight wiper assemblies, and the headlamp surrounds that go with 'em. Only ever offered on the P6 in your part of the world. Don't suppose you can help me track a pair down?
It totally does. I've always just got into something and figured out how it works as I went. Think this is fundamental to the human condition. But one can always put things off, expecting messy effluent and odours for example, as I did here.

I don't know where to start with those wipers. I made a couple of enquiries a few years ago when we last spoke of this. Let me see what I can find by way of resources. Sure it was never offered Stateside? Or on the continent?
 
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Tor

Active Member
Today I fitted a non-Lucas alternator, a 55A Bosch unit from late-1970s VW stock. With a made-up bracket from Alan in Cape Town, spacers, nuts and bolts it fitted in minutes and works an absolute treat. The original multi-plug went straight on, and there even a recessed spade terminal to take the floating brown live wire, not that I've tried it yet. Alan says it's a battery sensing terminal that is surplus on the P6 as the alternator takes its battery feed from the ammeter shunt?

The spacers were needed for it to line up with the pulley, as it's shorter (and also wider). The adjusting bracket sits on the other side, and there is now some space between the alternator and the water pump. Perhaps suitable for a future rad fan controller, with said spare +ve nearby coming in handy towards a relay. If I grind back the locating tabs on the shroud I can also fit that to it.

Result? Charge light goes out immediately. I can have main beams on at 650 rpm, maintain charge and the indicators no longer skip a beat. Wohoo.

I'll have to replace those green vacuum hoses, I see... Then there's the brake warning circuit. And... and...

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