Her name is Bella…..

[Nick Jones]

It’s not progressing very fast. And he really needs to clear his garage!

[Escadrille Ecosse]

21 minutes ago, Nick Jones said:

It’s not progressing very fast. And he really needs to clear his garage!

'Sup'? 

[Nick Jones]

Young sir worked the weekend so had today off. As weather forecast was untypically benign we decided to try and make a bit of progress….

Up in the air again….. old exhaust off. It was inclined to resist, but a short interview with Mr A Grinder put a stop to that nonsense. The actual pipe was fairly sound, if ugly. The aftermarket back box, less so, with a couple of crude patches attached with a sick pigeon.

Then we got to wrestle the manifolds off. It’s been a while since I had the “joy” of working on a car with the cast 1500 manifold. I haven’t missed it! Took the carbs off to improve access, which had the happy side effect of revealing one of the reasons why the carbs were impossible to set up. The PO had fitted quite a nice stainless steel heat shield. Unfortunately he’d reused what look like the original carb gaskets on the manifold side and used no gaskets at all, or even sealant, on the carb side. Clearly visible leak path on the front carb and a couple of dodgy looking areas on the rear. Planning to fit HIF4s on reassembly.

Going back together….. Phoenix 4-2-1 which actually fits fairly well (!) and plays nicely with the GT6 mk2 centre section (no silencer) and GT6 mk3 rear box. Went on reasonably easily apart from having from to remake one of the rear brackets on the boot floor which had had some traumatic mishap in the past. Looks a lot classier than the nasty tat removed.

Still have the carbs to sort and have also now noticed a rather scary looking brake pipe bodge to the OSR which needs sorting. No doubt there will be more!

 

[Escadrille Ecosse]

Definite progress. Always find more but the list does gradually gets shorter.

[egret]

Oh I can add some annorack knowledge here.  You can see the chamfer in the chassis rail that's the cutout to give better clearance for the 1500 exhaust, which is one of the few differences between a Mk4 and a 1500.  I know this because when I first got my spitfire it had a 1500 and no chassis rail cutout, and made a rather disconcerting noise under load where the 2:1 section of exhaust manifold rattled on the frame!  A 3mm steel shim on the relevant front engine mount solved this problem.

HIF4's definitely seem like the right choice if you can shield the float chambers from the exhaust heat, but I suspect you are well aware of this fact.

[Nick Jones]

Bella is being a bit of a cow (even a female dog).

After considerable messing around yesterday getting the HIFs fitted and the linkage sorted (all subtly different from HS), we started today full of hope.

Finished off the linkage adjustment and connected fuel. Even installed the float chamber overflow pipes). It fired up reasonably easily once fuel came through. Pleasing….. but then fuel started pissing out the overflows… especially the rear one. 

Tried bashing on the side but it was pouring out. Ended up removing the carbs (HIFs are NOT amenable to needle valve fettling in situ unless you have three hands, one with eyes in it) and checking needle valve condition, for muck and float height.  I had previously checked condition (relatively low mileage viton-tipped flo-jets which look fine). There was some new muck and the float height on the rear carb was well out. 
Thinking we’d found the problem we adjusted the float level, cleared the debris and reassembled. Was it grateful? Hell no! Both leaked now!

It then occurred to me that the original HS carbs had been inclined to flood too, and the mechanical fuel pump is new looking and fitted with no spacer.  Managed to cobble up a gauge and established that fuel pressure was somewhat over 6psi with the carbs overflowing vigorously. Too much!!

Then made some 2 mm PTFE spacers and tried 4mm then 6mm. This did drop the fuel pressure to 4 psi, but didn’t cure the leakage. Cue second carb removal which showed no new muck and apparently functional needle valves, still set where we’d set them previously. Dropped the float height to around 3mm lower than book on both and reassembled. No difference. Made a new pump spacer from plywood (!)

with 8mm thickness. This dropped the pressure to 2- 2.5psi, but still the carbs overflow, much as they did at the outset. 

They don’t leak whilst on choke or with the revs above 1800 rpm, but once revs are allowed to drop below that, they start to dribble from the overflows, rear one (second in line) first then front one, then one of them (usually the rear) will go full bore on the overflow and the engine will drown and stall. Basically none of the things we’ve tried today have made any difference and we’ve ended up where we started - apart from the death of hope.

Any ideas?
 

 

[Escadrille Ecosse]

Hmm. Not got much experience with these carbs.

The fact that they flood regardless does suggest something wrong with the float/valve.

Have you checked the interface between the two? Float contact isn't going overtravel and coming off the end of the valve?

And are the valve pin and/or valve body the correct height and able to be fully closed by the float?

And are they the correct float valves/washer? Don't know if these are different for the HIFs and H/HS carbs.

Edit. Had a wee look and there are three different valve assembling for the HIFs. Including spring loaded and plain needles.

 

Edited January 18 by Escadrille Ecosse

[Nick Jones]

All good points. They used to work in this form. I fitted these needle valves and plain butterflies when I put these very carbs on the Vitesse sometime in the late 90s, so they are fairly old, but probably did less than 15k miles.  They worked flawlessly then. Certainly no flooding. Age of the viton tips is maybe the issue, but they look good and still have resilience.  
 

I did give these a good look over, including opening the float chambers, before fitting and they seem in really good condition. Absolutely wasn’t anticipating any kind of battle like this and I’m amazed and disgruntled that our efforts today have achieved nowt.

The original HS carbs appear untouched since 1978 and need a complete overhaul.

[Escadrille Ecosse]

35 minutes ago, Nick Jones said:

All good points. They used to work in this form. I fitted these needle valves and plain butterflies when I put these very carbs on the Vitesse sometime in the late 90s, so they are fairly old, but probably did less than 15k miles.  They worked flawlessly then. Certainly no flooding. Age of the viton tips is maybe the issue, but they look good and still have resilience.  
 

I did give these a good look over, including opening the float chambers, before fitting and they seem in really good condition. Absolutely wasn’t anticipating any kind of battle like this and I’m amazed and disgruntled that our efforts today have achieved nowt.

Hmm...

Or just down to the innate hostility of inanimate objects. Unhelpful I admit

[rogerguzzi]

1 hour ago, Nick Jones said:

The original HS carbs appear untouched since 1978 and need a complete overhaul.

Hello Nick 

                I hate to say it but a quick clean up of these may have been better??

Still it's a leaning curve that gets no better in my experiance 

Roger

[zetecspit]

I have recently had teh exact same problem with HS6s on my sprint. After an little engine bay fire (ouch) got everything sorted.

The carbs, the bodies of which came from my TR7 powered Toledo and were a VERY good pair with no obvious wear (carb tops from a sprint) were treated to new  viton tipped valves just before "the fire" 

Since then I have had ongoing issues with flooding. I fitted new jets ATF (after the fire) and cleaned the carbs out. To cure the flooding they had new old stock genuine SU needle valves, twice. And now on another pair of viton tipped type. I have also lowered the floats/fule level with a washer on each. Still I had the front carb flood yesterday. Then cleared, no visible cause. 

The pump is the one from the Toledo, so was fine. It is getting boring now....

I have a filter after the pump, and really should swap it to the EFI filter I have bought which should be much better filtration. We will see what happens.

[Nick Jones]

8 hours ago, rogerguzzi said:

                I hate to say it but a quick clean up of these may have been better??

These are beyond a ”quick clean up” unfortunately. I’ve been careful to keep the set and all associated linkages and pipes complete, so no bridges have been burned. However, they are filthy, lightly corroded, need jets (and associated choke linkage conversion from wax stat), needles, needle valves and gaskets.

At this point I’m inclined to persist with the HIFs but try some new needle valves.  Though Clive’s story above is not encouraging……

[Escadrille Ecosse]

Given the things that have been changed without resolving the issues for both Nick and Clive I would suggest that it probably isn't excessive fuel pressure.

My bet would be the float - sticking or lifting at the wrong angle

the interface between the float and the needle - sticky or incorrect geometry somehow

the fit between the needle body and the valve body - needle too sloppy or roughness valve bore the meaning the valve will occasionally stick in the valve body

or the seat in the valve body itself - not square in the body or incorrect form

 

 

[Kiwifrog]

After a slight lay up of 6 months my TR3a had the same problem, I removed the viton gross jets and replaced them with standard and it fixed the problem. I was told that there have been problems with some of the viton tipped gross jets, not sure if needle valves are affected as well.

cheers Alan

[Nick Jones]

Been looking at the Burlen website.  I’m sure we are supposed be grateful that they are keeping the technology alive…… but their pricing can only be described as predatory.

£23.35 for a single needle valves. £22 for a single metering needle, £46 for a single float(!!), so the parts cannon approach is not an option!

Price for a complete overhaul kit for the HS carbs is £215 (pair) and while this represents a significant saving on the individual parts it contains parts I don’t need (spindles), parts I don’t want (wax stats!) and excludes others that would like. The cost is more than I spent injecting the Vitesse - 20 years ago I know, and done on the cheap, but even so!

So next moves are to fit an inline filter, clean out the carbs again, check the float heights (and rubbing surfaces float vs needle valves) and perhaps try a temporary install of the Huco pump.

[thebrookster]

45 minutes ago, Nick Jones said:

Been looking at the Burlen website.  I’m sure we are supposed be grateful that they are keeping the technology alive…… but their pricing can only be described as predatory.

Agreed, it scared the bejesus out of me when I had to sort the GT6 last year! 

I actually hunted out some old receipts, and proved that I paid more for some odds and sods last year than I did for entire rebuild kits for the saloon carbs!!

[JumpingFrog]

+1 on Burlen's pricing, makes parts for DCOEs and DHLAs not look that bad.

Recently needed a pair of HS jets, couldn't  find them anywhere for less than £30 each, similarly last week I was pricing together a rebuild of a single HIF44 I've acquired for an experiment, well over £100 since I'm missing a throttle arm as well...

Can't add much to whats already been said, other than that recently I've had issues with the Viton tipped needles on the HS2s on my Herald. Something has changed in the petrol blends in the last few years (and I always buy E5 now), it seems to cause the needle to weld itself to the seat if left for more than a week. But this is the opposite issue to what you're having...

Edited January 19 by JumpingFrog

[zetecspit]

6 hours ago, Nick Jones said:

 Though Clive’s story above is not encouraging……

I have today done 170 miles. No issues. 

I wonder if there was some residual crap in the pipes after the filter.

The filter is a clearish plastic one, but is made by Delco so hopefully some quality is there. I fitted it after the fire. 

I REALLY must dig that new filter out and fit it. Not to mention sorting the fag lighter socket for the satnag, which was "inconvenient" this morning.

[Gt64fun]

18 hours ago, Nick Jones said:

Basically none of the things we’ve tried today have made any difference and we’ve ended up where we started - apart from the death of hope.

Nick

Oh dear, sounds as though you are having a tough time. I feel your pain.

Your initial post prompted me to find out a bit more about the HIF (horizontal Integral Float chamber) carbs. Sounds as though the Zenith Stromberg might have provided some of the inspiration for the architecture.

https://sucarb.co.uk/technical/technical-carburetter-maintenance-settings-hif

Certainly your starting fuel pressure of 6psi won't have helped and I applaud your ingenuity (or desperation) in making spacers from 'available' materials.

Assuming everything is assembled correctly (I don't suppose the floats can be fitted incorrectly) and the fuel supply is clean, it can only be the float valves.....surely! I have always used just the standard valves (not Viton tipped ) on my Stromberg 175 CD2s and anytime I have have had flooding issues, it has always been crud in the valve. Luckily the design of the Strom allows the float bowl to be taken off in-situ, the valve removed and some fuel sent through to flush it.

Hopefully if you do change the valves that will sort it. Is the car required for daily transport?

Ian

[Nick Jones]

Thanks Ian, it was definitely feeling like the spirits were against us…. Or as Colin puts it…..

18 hours ago, Escadrille Ecosse said:

Or just down to the innate hostility of inanimate objects

Hostile; Damn Right!

Still might just be crud, but it’s subtle crud!  I’ll fit a filter - should have already really but nothing very suitable in stock.

The plywood spacer probably needs changing for something proper. I did smear its internal surfaces with RTV but I suspect it’ll sweat oil fairly freely! 

Or maybe we’ll “Huco” it. Even FI it given that we have a pretty much complete kit that came off Chris’s 1300. The trigger wheel is the issue as pulleys are different. Can’t remember how @rogerguzzi has done his now….

Meanwhile, I forgot to mention the positive from yesterday, which is that we got to hear the new exhaust and it sounds nice. Fruity without being too loud, not that it’s been tested under load yet……

Fortunately it’s not required as daily transport, but we could do with it working to find out what else is wrong with it!

[egret]

I have a 1500 pulley with a trigger wheel on it, can't get it off the crank though.  If I manage to get it off you can have it!  I can get you better drawings for the current solution I have if that's of help.

I'm definitely biased, but if you can do efi for comparible cost, then why wouldn't you? Possibly insurance, or any classic racing aspirations?

[A30Racer]

That is very frustrating, Nick. I have every faith that you will conquer the little blighter. It will most likely be something quite trivial, which makes the pain seem more acute at the time!

[rogerguzzi]

18 minutes ago, Nick Jones said:

Or maybe we’ll “Huco” it. Even FI it given that we have a pretty much complete kit that came off Chris’s 1300. The trigger wheel is the issue as pulleys are different. Can’t remember how @rogerguzzi has done his now….

Hello Nick

                This how I did mine on the first engine but I moved the sensor on to the timing cover on the second one (forgot why probably better access?)

It's just bolted to to the back of the pulley on a suitable register

Roger

[Nick Jones]

Thanks, how’s the trigger wheel attached to the pulley? Small step machined in it?

[Nick Jones]

1 hour ago, egret said:

I'm definitely biased, but if you can do efi for comparible cost, then why wouldn't you? Possibly insurance, or any classic racing aspirations?

The owner is non-technical, though he’s coming on. Car is still largely an unknown quantity so really I’d prefer to keep it simple and standard-ish at this point.