eddyinfreehold

Nice one. Once drained it's surely straightforward to test-fit finger tight first. When sealing for good other folks have suggested that a bit of care is needed tightening up to the female nut receiving the pipe and olive which is welded ... or possibly brazed... to the tank so as not to damage that connection. Really interested if you sent a photo of the successful union and tap.

That makes complete sense, thank you. Of course the BSP size is larger to fit the copper piping of domestic plumbing before 15mm became standard, 1/2" UNF then ...

Pete, have a read of the thread below, "Spitfire Mk 3 Tank...Long Story" . It relates to my recent experience. I took the cut off pipe, nut and bu88ered olive into several hydraulic engineers on our local industrial estate in a small city in North Lancashire. I found a bloke who gave me the time of day in the third place. I handed him the part in the attached photograph and in 2 minutes he came back with the fitting you can see attached to the new tank. Whether one is available with a reliable stop valve or tap I have no idea. Perhaps inserting a stock fuel valve in line separately might be a better idea. My experience of fuel valves/taps over time is that wear or seals fail and they weep. In the rare event you want to shut off the fuel I would just drain the tank and be done with it. Having spent a lot of time kneeling into my Spitfire boot I can recommend you buy two or three standard plastic washing up bowls for domestic sinks to receive the petrol as it drains away and have cans and a funnel ready to receive what you drain. Safety first. In terms of the thread, and I am not absolutely certain, it is either a 1/2" BSP or UNF with the JIC 37 degree compression fitting. The JIC fits wonderfully and makes a great seal. They may actually be the same or very close threads. By the sound of it you may well have parts in your inventory. I hope this helps. It is not absolute but it will be a lot better than trying to find an olive to fit your original nut and pipe. I'm certain Melbourne has a far better selection of hydraulic engineering suppliers than Lancaster or Morecambe. Great city ... would love to visit again. Eddy

Interesting Pete....so it wasn't a farmer's myth...

Over the years I have learned to agree with what you say JohnD, it's what contractors hiring in plant call 'old petrol' that has lost most of the volatiles designed for modern small engines. They tend to drain the tank if it's a bad starter and refill. Someone also once told me to drain the tank on a 4 stroke engine before winter and refill in the spring. Modern engines such as Honda, Kubota, Subaru/Robin etc tend to have steel tanks protected from rust internally. I have also been told to drain a 2 stroke plastic tank from a chainsaw, hedgecutter, leaf blower or strimmer to remove all the oil, run with a dab of pure petrol for a minute or less then drain that and leave it dry overwinter. It is certainly true that a 2 stroke motor left for a long period with its 25:1 or 50:1 gums up badly as the petrol evaporates and leaves an oily residue and is a bu88er to start. I guess the bottom line with a strimmer or a Triumph Spitfire is the more you use it the more reliable and stable it is.

In my professional life I'm a cricket groundsman. I get to deal with a lot of rather left field specialist machinery such as mowers, spikers, scarifiers etc. and because they get worked hard a certain level of in house mechanical work is required. Until recently we had an ancient Greens Griffen road roller for compacting the pitches run by an enormous 3 cylinder Lister Petter diesel engine. It was a handle hand crank which took a certain knack and a lot of grunt. I dreaded every spring as it was a beast to start again after the winter layoff and coughed and spluttered for half an hour first time out. I was talking to a farmer about this one day and he told me never to leave a tank half full over winter. Always fill it to the top. That prevents condensation on the inside of the tank wall. The spluttering was water which had run down the tank wall, settled over the take off pipe (lowest point) and been pulled through the line to the injectors. From then on I filled to the top and never had a problem again. The same thing may be the problem with rusting. Some people habitually run their tanks half full or less. Some always refill to the top. Triumph Spitfires do a lot of standing about over winter. The random rusting could be due to condensation in tanks with only a bit of petrol in them. Just an idea....

It's a perfectly academic debate...the whole thing is history now. However if you had designed the tank pressings in the first place to simply slot in two baffles, you could have done away with the bloke in the brown coat on the folding machine making the baffle tabs .... and the bloke in the brown coat wielding the spot welder. Much cheaper. My experience with mowers and diggers etc of welding bits that wear or break is that there is a portion of steel around the weld that becomes very brittle. Just saying...

Fair enough, each to their own opinion. I'm not saying I'm right, I'd just have done it a different way. The spot weld hadn't rusted through, it had physically broken taking a tiny circular piece of tank with it. You may just be able to see this in the photo. I'm not saying it's a technique that doesn't work, it's just that the spot welds are something that can compromise the integrity of the structure. It would be perfectly possible to make an insert that could be simply placed in the tank to serve as a baffle without it rattling about. Just as easily, very similar baffles to the ones used could be slid into grooves with just a minor change to bolf halves of the pressed tank. They wouldn't move either.

....thanks all...... I thought I'd write a quick update seeing as there is some very wise advice above on purging tanks and safety. The tank was left outside until yesterday ...about 16 days... with all the orifaces open to the breeze, filler, drain and gauge sender. I'd read about plenty of horror stories with exploding tanks so was very cautious. I think my favourite was a bloke who attempted to get some grit out with a hand held vacuum cleaner and turned it into a jet engine that burned his garage down. No idea if that's a true tale but it's a good one. After 16 days exposed to the air and originally very petrol smelly, I could not detect any fumes at all by nose yesterday. I filled and drained the tank with fresh water twice, placed it on a scaffold outside to dry in the sun. No smell at all, no film of fuel in the wash water. Confident it was safe to cut. After an hour I lit a diesel moistened rag and pushed it through the filler hole without issues. The rag burned out in about 5 minutes with an impressive chimney effect through the filler hole. NOTE ... I DO NOT ENDORSE THIS METHOD OR SUGGEST OTHERS TRY IT, I MERELY SUGGEST I WAS HAPPY THAT I HAD PURGED THE TANK OF FUEL IN THIS CASE ... Took the grinder and cut the tank in half. I then discovered that inside are two thin steel baffles (see picture) to alleviate fuel slopping about. With a bit of wrestling I managed to break enough spot welds to pull the tank in two. On examination the tank was just about perfect inside, thick shiny steel with only the very slightest discoloration in patches you could call rust. That annoyed me. I'd wasted money on a new tank assuming mine was paper thin and leaking. The baffles are push fit with bent over tabs folded to sit against the tank walls. The two halves of the tank are then put together and sealed. The baffles are then spot welded from the outside as far as I can see. The penny then dropped. The pinhole leak I had was where a spot weld had failed allowing petrol to weep out. This had been patched years and years ago. Just my take on it but what a bl**dy silly way to make a tank with baffles inside. Anyone else had a similar observation? Worth checking if anyone has a leaky tank. It should be a simple task to locate the spot welds, check each one and repair and repair from the outside

If you look at the paintwork below the new tank you can see the light red respray paint that peeled off, the original darker red as delivered and the yellow protective undercoat from 1969. Plus as you say, the sealant between rear bulkhead and boot floor unpeeled. Two hours of petrol immersion did it all. Will have to re-seal the panel joints and make good with paint ... although there is an honest argument for resealing then leaving it as it is behind the boot card as a piece of history I could put into the file. I do not want to be in that position again on a filling station forecourt.

I've had this car for about 3 years now and have been slowly ironing out the mechanical faults in it. The bodywork and chassis are superb for its age. I posted last year about rebuilding the carburettors and there was some discussion with very helpful advice on throttle return spring location. I've solved various front caliper issues but generally all has been good. New story. Once it was appropriate in our covid19 world to feel safe taking the Spitfire out for a run in May, I decided to fill the tank to the top for the first time and have a long run, perhaps 150 miles plus. Having travelled 1 mile to the local forecourt and filled up, went to pay, came out and found fuel pi55ing out of the boot onto the floor. Panic. Removed spare wheel. Removed rear boot card. Petrol leaking from a pin hole on what was clearly a tank patch. Stuck my thumb over it and was able to stop the flow. Felt like the Dutch boy in the Dyke stopping the sea coming in. People come and go and stare, some took photographs of the car !!! until a contractor from Warrington pulled up in a Transit pickup. We had a discussion and to cut a long story short he went back into town and came back an hour later with a roll of gaffer tape. When most shops were covid shut! It solved the problem immediately with enough tape. Never got the guys name and he wouldn't take any money. Total hero. there are still good guys about. My thanks to the gaffer tape man from Warrington whoever he may be. Anyway. First step was I siphoned the tank to near empty. Four gallons into cans I think. About another gallon lost on the forecourt over two hours. Did a lot of reading about tank repair .v. replacement and decided upon a Rimmer non OEM steel tank. The SAFE OPTION. That arrived about a month ago as the full kit including new sender, seals, bolts, washers etc no problem. Set to yesterday, first opportunity. Removal of the original tank was straightforward though it required sockets with extension rods, spanners cannot do it. Installed the new tank and then the problems started. The securing bolt holes from the non-Oem unit were poorly aligned but I managed to secure 4 out of 5 after 2 hours sweating. The rule is secure the bottom ones first and only just thread each one sufficiently for it to stay in place, then tighten up as if you were torquing a head so as not to strip threads. Tank in place. Filler tube is now too long and prevents filler cap assembly from fitting flush to the rear bulkhead body in front of the boot, it protrudes by some 3/4" because metal touches metal and there is also a slight misalignment but the short hose can be connected. I can't resolve this at the moment but decided to leave the filler cap proud by 3/4". On reconnecting the fuel pipe and tightening it up I thought we were on a roll. Not a bit of it. I poured half a gallon in and it started dripping straight out of the pipe connection. I didn't want to strip anything but as tight as was reasonable it would not seal. Rethink. Took a plumbers pipe cutter and removed about 4" of pipe on the L bend including the sealing nut and the well fixed olive. Off to the motor factors who ummed and ahhed but couldn't help, but suggested I try an hydraulic engineer. Looked up several and on the 4th attempt on our local industrial estate found an enthusiast who was interested. He provided me with an hydraulic connection elbow, a JIC 37 degrees ??, that threads into the new tank perfectly with a solid seal. The elbow can be rotated to the appropriate angle to align with the cut off metal fuel pipe then similarly tighened up to seal. The union between the original fuel pipe and the new hydraulic elbow is made with 5mm i/d modern ethanol proof fuel pipe and appropriate hose clips. Refilled with 1 gallon of fuel. Waited for an hour. No leaks. 2nd gallon. One hour. No leaks. 3rd Gallon. No leaks. The next stage if its all sound is to take it to the filling station and fill to the top to check the sender seal. A 45 min 10 mile run tonight with 3 gallons slopping around showed no spillage. Worth noting that the old tank had a replacement sender identical to mine and the rubber washer on the float was missing and the float was chock full of petrol, explaining why the gauge never registered. Poor quality. Not expecting wonders. Might remove it later and put a more reliable float on. Looking at the old tank I'm very tempted to repurpose it as a smoker/barbeque if I weld some rebar legs on and cut the seam in half.

Pete. Totally get where you're coming from here. No worries. Latest update is I went back to my machine shed at work on the cricket ground and went through my spares. Two decent Briggs&Stratton 13hp throttle springs are now doing a decent job even if they look a little ugly. There is virtually no tension on either spring here yet they return the butterfly very well. Also Pete, I was wrong. I removed the 'angel wings' from behind what I assume is an OEM rectangular spring retaining plate. They appear to be home-made from perhaps Dexion shelving or something like big meccano with chipped paint and different dimensions. Did someone once have the wrong size springs? Photo attached. As fitted and working with old springs shown lhs and old 'angels wings' rhs.

Pete. Our messages have cross posted. I don't think that diagram relates to my setup. That's a sort of bellcrank arrangement from what I can see. Mine are just fixed anchor plates bolted to the manifold. The choke is a solid unsprung wire in a sheath. It's not even a cable. It just pushes back and fore and is connected directly to the jet mechanism through the twin linkage.

Thanks again both. I'll spend some time on a spring hunt. I'm wondering firstly if this set up relates to a one-size-fits-all solution to vehicles being sold to both home and overseas markets with alternative carburettor arrangements. There are holes on the flat plate and two on the 'angels wings' after all. Secondly I am thinking that at some point in the last 50 years the brackets have been removed and replaced backwards and no-one has noticed! They would be perfectly sound the other way round. They do look 'factory made' and not a piece of home-shop work.

Thanks Pete & Mad4Classics. I have that plate as you can see with its two corner holes, and also the 'angels wings' behind with two larger holes. The original plate looks standard but I will have to locate much shorter springs & of less strength to accommodate this setup. Any advice for sources? Any idea where those 'angels wings' behind have come from?

The current arrangement is exactly how I bought the car. It struck me as clumsy that the springs fouled the retaining plate in front. My OEM manual seems to show completely independent spring mountings cast into the inlet manifold (pp 1-309). On my vehicle I seem to have 'angels wings' behind the plate that you show in your photo to which the springs are attached. I'll try and dig out some better, weaker springs to fit the plate as shown in your image. I totally get the imbalanced pressure these springs give, as if the inside point of each spindle is being pulled towards the nearside, using the outside point as the fulcrum. That's the best way I can explain it. Thank you all again.

My bet is they're the latter, they have a bakelite sort of ring to them. Still better safe than sorry. Thanks for that Mad4. 30 mins to reassemble in the car and primed the float chamber with fuel. Started first turn of key. A bit of jet fiddling and we're close. Off to my local garage to balance them properly and check the emission reading. The noise is mostly the wind on this film but it's bubbling nicely at about 950rpm. 20190807_123114.mp4

Wouldn't checking the compression first be the best option if you suspect problems in that area?

Thanks Peter. Bu88ers to clean though. All the gasket stuck to them. The manifold and carb faces/flanges are clean. Let me try and attach these films of the spindle while I'm at it. Not sure how big the files are... 20190804_143123.mp4 20190804_134732.mp4

...whooh...just came back to report progress and ask a few questions and I find most have been discussed already. Brilliant. Right, It's all done now and ready to refit. The only other question I have relates to the last four hours work. Yes four hours ! There are two c. 1/4" spacers or shims that are gasketted between each carb and the inlet manifold. The old gaskets were very tatty and thick and it has taken ages of paraffin soaking and gentle scraping to clean them with a paring knife. I've met similar spacers in many BMC vehicles and a Volvo too. The manual makes no reference to them. As they look a bit like they're made from asbestos I scraped them 'wet' . If anyone says I haven't cleaned them fully The pink residue is just colour. I put a calipers over them and they are of even thickness. Are they designed as heat insulators or are they adding a crucial length to the manifold? I've also made a short film of the old spindle wobble which I'll post later this week. The front carb was more obviously worn than the rear. Eddy

Oops. I should have looked more closely at the postings from the other site. When I am sorted with these carburettors (see Fuel System) I will have a look and repost. Yes I get the Spitfire hinges have their own separate rods though not as easy to inspect or photograph.

Well. Rain all this week has delayed progress. That's because of work not the carbs. I'm a cricket groundsman. Finally got them off last night, washed off in paraffin and cleaned. I spent the late afternoon rebuilding the rear carburettor. No particular issues. Yes, there are no spindle bushes to worry about in my case thank goodness. Although the original spindles were badly worn and rattling around in their housing there appeared to be no damage and the new spindles fitted well and very snugly into their alloy housing in the 1.25" carb body. All the rest of the breakdown and clean was straightforward with various new bits of rubber, jets, springs, float chamber and valve pieces etc. Pictures attached. Note the extent of the bearing area wear on the old spindle....

This is my UK G Reg 1969 mk3 .... from what I can see it looks like a single tube and a seam is exposed in one place!! The car was extensively renovated well before I bought it so the part may be non original or even fabricated. I hope it helps though. Eddy

Thanks for that Badwolf. That's a shame. The car was in poor condition even in 1980 when I sold it to two enthusiasts. I lost touch with them a year or so later. I had some memorable times in that car 😆

Colin, Pete, David Many thanks. I will be able to start tomorrow I hope so I'll let you know how it goes along. I'll be glad to get this part done and on with some driving. The refurb kit includes jets but not springs or needles. Still, they can be replaced with the carbs in place I guess if that proves necessary. Tremendous speedy answers, thanks again gents. Eddy