More Exhaustion

 

After the last update and the start of the exhaust system I continued with making my slip couplings on the newly fabricated first section. These are made of some slightly larger diameter steel and have been welded on to the two horizontal sections. I initially had two stainless steel slip couplings (clamp on) to attach the pipes together however they were basically dog shit and wouldn’t compress/clamp onto the pipe so they were done away with in favour for these slip couplings. I welded a nut onto each end after drilling a hole through, this will allow a short M8 bolt to nip up through onto the sliding section and stop it sliding out. It’s a relatively good friction fit anyway and will have some exhaust paste on final assembly however prevention is better than cure. 

The next section was to weld a 45 degree angle onto the leading 90 degree leg. This will now direct the exhaust horizontal along parallel with the sill. This is just a case of mocking up on the car and marking accordingly before a few tack welds then checking everything before fully welding together. Just after the 45 degree bend I have also welded an expending cone which goes from the 38mm diameter up to 45mm this is the same as the original spitfire exhaust which in theory should keep the back pressure equal and not restrict the performance. 

It was all coming along quite nicely but the next bit was to notch the secondary down pipe and weld into the primary pipe. Another reason to have the slightly larger diameter pipe just after this join to cope with the increase gas flow. Before I cut this for real I used an off cut of pipe and made a thin cardboard sleeve in order to cut with scissors and practice the angle and cut for a good fit. This was all fairly good fun, and whilst I’m sure there are other ways to calculate these angles as long as I get the end result I’ll be happy with that. I’m no professional fabricator this is all part of the fun of kit car building you have to be a jack of all trades.

So after I was happy with the fit of my practice piece  I simply used masking tape to make a template then transferred it onto the secondary down pipe. And I’m pretty bloody happy with how it turned out. The notch cut was nice and uniform all the way round so will weld up nicely. I marked the circumference of the secondary with a pen so when it was all removed I could see the area I needed to remove before welding up. Then it was out with the grinding disc again and start cutting away. I have sacrificed another Dremel multitool during this project my first one lasted years and years and now I’m lucky if a get one to last 18 months…and I’m not giving them a hard life. 

 Once cut out I filed everything smooth everything was welded into place, after a few tack welds and trial fit first. Then when fully welded I dressed off the top with a flap wheel and then I could make a start on the exhaust wrap. I managed to get 30 meters of exhaust wrap online for only £10 so was happy with that and it’s a nice titanium colour so looks great also. I wrapped the exhaust in two sections first the upper pipes that come off the manifold up to the slip couplings, then the further two pipes as they come out the body and down along the main side pipe up to the edge of the drivers seat access. This should help keep the heat down directly under the carburettor intake filters and also reduce the risk of burning your legs getting in and out the car…. Not that I have ever done that in the Cobra either but it will help soften the blow if it does happen.

I can’t continue any further yet as I’m waiting for two further 90 degree bends to be delivered that have gone AWOL in the post. But when they arrive I will be able to finish the exhaust up to the rear silincer, which will be another custom fabrication idea that I have. I’m really pleased with how this exhaust is looking so far and it will genuinely be exciting to hear what it sounds like when I get the engine running still need to get the carbs built up properly first. 

Exhausted Beyond Belief

So on this update it’s all about the exhaust really. I wanted to try and do one blog update to cover the full exhaust fabrication and install, however everything escalates and takes a slight tangent so we’ll have to cover it over two or three. I started off ordering some mandrel bends and sections in mild steel, I’m not setup for stainless steel welding so mild steel will have to be ok and in fairness it should be more than durable for its use. I have a good idea how I want the exhaust system to look and the style to suit the car so I’m fabricating the full system to achieve this. Starting at the manifold end I used the original down pipe and cut the old pipes off the flange plate, I will be using this still as my fixing point onto the manifold. The original down pipes are a 38mm diameter (1 1/2”) so my new pipes are the same to hopefully keep the exhaust pressure equal and not restrict performance from the mighty 1500 engine. 

I started by fitting two knuckle 90 bends to the flange plate, these are welded in place and the spigot into the flange slightly to give strength as the rotation of the engine under power and vibration. Then off of these two knuckles I have added two straight lengths which will take this new section up towards the body tub inner wing.  I have been tack welding this all up first and making small adjustment and alterations as needed then fully welding and dressing when I’m happy with the fitting. 

Next stage is to cut some holes in the wing and fit some 90 bends to run the exhaust down the exterior of the body. With the first section temporarily fitted to the manifold I used a straight edge to follow its line to the inner wing and made some markings roughly marking the diameter of the pipe and where I needed to cut the hole. 

Then it was out with the hole saw and make a few nervous cuts. My idea is to have a slip coupler fitting the vertical section here to the 90 degree section as it exits the body which will also make the exhaust removable at a later date and for service reasons if needed. Once the two holes were cut out I filed and rounded the edges off slightly making sure there was adequate clearance around the pipes. The exhaust front section will be wrapped in heat wrap which will help keep the engine bay temperatures down slightly and also help cover all my welding joints.

I now am able to fit the two 90 degree sections which will send the exhaust down the external of the wing where I need to make a two into one collector or Y piece as such, I’m still working on this as I’m wanting to also increase the diameter of the exhaust section after this point to something closer to 2” as it travels along the length of the car parallel to the sill. I don’t have this bit of tube yet but I need to keep its diameter to something close to whatever silencer I use… and in mild steel also so I can weld it. 

 This has all been fairly trick to get fitting correctly so far as the horizontal section of the first section runs close to the steering column and I can’t risk any potential voiding, especially when the engine is under load. But the tight knuckle 90 bend directly on the flange plate lift this section just enough to give a good clearance even when taking into account the exhaust wrap later on. 

 My next little task was to run the main battery feed from the battery in the boot along the nearside inner sill and up the front firewall to the solenoid. I used 170amp cable to achieve this which is really overkill for a small capacity 4 cylinder engine, but this lesson I have learned previously with the cobra build as I only used cable then which just meets the amp demand for the engine size and it can struggle to turn over when really cranking for a period on a cold start. The battery cable now runs the length of the sill and I will clip it down at a later date but I have also fitted a batter isolation switch just in front of the passenger seat which is easy to reach in case of emergency. The cable now passes through the front bulkhead and directly up to the starter solenoid using some good heavy duty crimped ring terminals. I’m paying huge attention to the routing and clipping of all cables that are viable as this is wha will help push the quality standard of the whole build and help towards the final product presentation, making it look less of an afterthought installation. 

With the battery feed now installed and the battery negative to the chassis also I could now actually spin the motor over using the solenoid. I’m now sort of at a stage where I can make a start on the full electrical system and start to make some decisions in regards to the custom loom and fues/relay layout positioning. Wiring I find extremely satisfying but also complex to get the correct rated wire and colours for each circuit. Luckily I purchased a USB Spitfire service manual from Rob T (the online Spitfire guru) which has a wealth of knowledge and many many many PDF files covering all aspects of the Spitfire which is going to be really helpful and provide much further specific detail than a Haynes manual. 

On Guard

 

Here we go with a long overdue update. Sorry it’s took so long, but I have been really busy and have not had much garage time over the summer months. Still here we go with the front mud guards which have been a real pain in the ass to be fair and not very enjoyable to fabricate. I started off with the fibreglass shells which as you can see pictured here, are far too big in regards to their radius. I spaced the guard off the tyre simply by using a roll of masking tape which sits the guard off the tyre by about 36mm. I kept the leading edge at around the one o'clock position and intend to cut/trim the rear of the arch around the nine o’clock position, to create a smaller but better looking arch for the front tyres. The fixing brackets are literally just some flat bar that I slowly bent and manipulated to suit the position of the mud guard. This is a very very tedious process as it’s important that the arch is held firmly and securely and keeping the arch sitting evenly and following the radius curve of the tyre.

The main fixing point is a bracket I fabricated out of some 4mm steel that will bolt onto the front stub axle. This then creates a solid fixing point for the two arm brackets to support the arch. I can’t fix the arch on or anywhere near the front suspension arms as I need to allow the suspension to travel and the wheels to turn without voiding on any of the brackets so onto the back of the stub axle is perfect as it will then allow the arch to travel and turn independent to the suspension. This bracket is a great solid point to work from, so I’m relatively happy with this bit, one for each side so now onto the bracket arms. 

The first support bracket was bent and manipulated to suit how I wanted the arch to sit. I temporarily clamped it onto the stub axle bracket before I drilled through two m8 fixing bolts. This took a really long time to get a good fitting and lots of careful measurements took place to keep the arch sitting evenly around the tyre. But once I was happy with the front bracket I drilled through the arch into the bracket and used a slice of rubber hose to act as a spacer/shock absorber on the arch. I used some nice hex head flange bolts that hold it all together with a penny washer and nylock nut on the underside keeping it off the tyre tread and should offer a little more resistance to the road vibration that will be a constant issue for these arches…. Time will tell if they will hold up. The rear support bracket was bent and manipulated in the same fashion as the front but has considerably more angle to it compared to the front one. I added a strengthening section of steel on this bracket which was welded into place and had massively reduced the amount of wobble in the whole setup. I think I need to add a further support between the front and rear bracket also to help with the potential wobble as I don’t want to be replacing or repairing after every road trip. 

So with one side pretty much sorted I had to replicate the process for the other. To be fair this was a tad easier because the stub axle bracket was exactly the same as were the arch brackets just facing the opposite direction. I removed the first set and replicated again using flat bar steel with the angles they were bent too. And after a mock fitting using clamps the second arch was sitting in a very similar and uniform position to the first…. Which was nice. I did have to make some adjustments to get it perfect for me, but once done it was drilled and bolted into place same as the first one. 

I haven’t really enjoyed making these front arches and so I’m glad to have got to a point I can just fine tune them now. I’m going to have to restrict the steering rack as the now mounted mud guards/arches will void the body tub slightly and possibly on the headlights if travelling through suspension movement, I’m hoping to get this to an acceptable turning rake without compromising the drivability of the car… two possible solution would be to create a cutout in the body to accommodate the edge of the arch on full lock, or secondly just remove the arches altogether and run without them…. I’ll see how I get on and act accordingly later down the line. 

I’ll finish this update with a full video walk around of the car so far. It’s daunting how much more there is to do in order to get finished, but tremendous to sit back and look at the achievements so far…. So much work and commitment has gone into it all so far, and much more still to come. 

Laying Lines

 

On the last update I had made a bracket and mounted the fuel pump, so this time it was time to get the fuel lines in. I have opted for a hardline this time round as opposed to full length rubber flexi hose. I want the fuel line to be a as durable as possible and less responsive to E5 or E10 variants so a copper hardline will cope with anything so let’s get it in! 

Hottest day of the year today so glad I was able to utilise the sun to help heat up my copper spool to aid with bending and manipulating it into position. This is a 8mm spool which is a tad overkill for a carb engine, however it’s better to oversize than undersize. The fuel will be regulated just before the carbs but if I was to have only used 6mm fuel line there could be a risk of fuel starvation which would seriously effect what little performance the 1500 engine will produce. 

I wanted to run the fuel line in one continuous run… however it is physically not possible with the bends needed. It “could/would” have been possible prior to the body sill getting fixed and bonded onto the chassis but alas that is too late in the build stage for me now…. Bugger.  So three runs of hard line front to back with two compression straight couplers needed in certain places. I started off with cutting the hole in the boot floor and fitting a rubber grommet to protect the copper line against the sheet metal boot floor. The position I have already calculated when bodging up the first attempt with the fuel line and this is also where one of the connector will be.

The second leg of the fuel line is simply following the outer chassis sill and a bent up and along the underside of the boot floor into the compression coupler. I have had to remove the offside rear wheel, mudguard and radius arm to give me access to get all this, and I still need to get back in at some point and fix the fuel line with some clips (which I don’t have yet) I will get some protective sleeving to cover this section of the line also, whilst it is in to risk of direct hits from road debris it will just help protect from the elements as such. I will also need to seal off the lower section of the rear bulkhead which you can just see as the fuel line runs through it, but this is relatively easy later on with some PU sealant and some offcuts offcuts of sheet metal.

The main run of fuel line is now easy to run along the sill length, unfortunately with another straight coupler along the length. Then it runs through another grommeted hole in the front bulkhead and bent up towards the fuel regulator. I have used some braided fuel line from the copper to the regulator and intend to do the same from the regulator to the carbs with a fuel pressure gauge in line also. Unfortunately the unions I ordered haven’t arrived yet so I will have to postpone that for another time. But with the main run from the tank to the engine bay now mostly in place and sealed up I was able to drop some fuel in the tank and pressure up the line. I started off just blocking the output from the regulator as I wanted to run the pump and fuel lines under pressure for a while to confirm all joins are sealed and no risk of leaking and I was pleased that everything held nicely with just a small nip of the fitting next to the passenger seat to get it to seal. Once I had done that I was happy just to run the fuel through the lines back into my gerry can which will help flush any debris through and into the filter, this will get changed after a few miles on the road and after a couple of full fuel tanks have passed through the line. 

Expansion and Pump

I’m glad to report since the last update a few weeks back that the diff hasn’t dropped one bit of oil, so I’m confident to say that I should have sorted that issue. Next up is a few little jobs to help get everything progressing. First up is an expansion tank or header tank for the cooling system. With the radiator being relocated much further forward than originally and access to the pressure cap tricky I have devised a plan to update the cooling system that I hope will work well. First off is the tank itself, this is just a basic 1.5 litre alloy unit off eBay for around £30. I will replace the pressure cap with a correctly rated pressure release as per the original setup (13 Psi) and the second cap on the radiator which is not really accessibly with a higher rated pressure release which will then in theory act as a fail safe if needed. The new tank will be mounted on the bulkhead firewall as high as possible to help the cooling system bleed itself naturally, this is doubly important because the radiator is also now lower than the original Triumph setup so risk for airlocks could be high without this tank. The installation is basically plumbed in to replace what would be the heater matrix within the original setup. 

From the water pump outlet side the coolant is pushed through the thermostat and then on through the radiator, however it is also diverted through a secondary outlet (black question mark shaped hose) through the inlet manifold and on to what would have been the heater matrix inlet. The reason to heat the inlet is to stop ice forming and keeping the fuel vaporised during winter cold drives. I don’t think that will be much of a risk with the nature of this car, however if you deviate off script then you normally create further issues to resolve. So the secondary outlet is now running through the inlet as it should but now is just the returning to the top feed of the new expansion tank. The bottom outlet of the tank is just going to be connected to the return feed pipe that runs under the exhaust manifold (yellow arrow) this tube I have upgraded to a stainless steel replacement as it fits with a compression and olive fitting into the water pump, and they a prone to leaking and corroding so a stainless unit should be much better. 

Next up, fuel filter. I plan this whole build in my head weeks and months before I actually do it, so find myself trawling eBay etc.. for parts and components that I will need later on. This filter is also a pressure regulator to keep the fuel delivery to the carbs consistent and new they cost in the region of £100, this one was £35 so a significant saving made there. I have to mount the filter in a fashion that suits my setup best, so simply remove the top four bolts and rotating the top section of the body allows me to point the inlet and outlet in the correct directions needed. Then with a small angle bracket cut and painted I mounted the whole thing on the bulkhead with the inlet pointing down to where I need to fit the fuel pipe run from the fuel tank. I’m considering fitting a fuel pressure gauge between the outlet of this filter and the inlet to the carbs, they look cool in my opinion and will add some bling as such to the engine bay… not to mention being able to set the pressure to the correct 7psi required for the carbs. 

So next on the list is the fuel pump itself. I have opted for an electric fuel pump over the original mechanical unit simply because I like the idea of the toggle switch on the dash board to turn it on and off… pure vanity I know but that’s what I want. The pump is a Facet red top which over exceeds the requirements for the engine so it should work well within the setup. I have made a bracket which the pump is rubber mounted on to help isolate the noise and ticking of the pump when in use. I have two two rubber mounts on the lower of the bracket where it will mount to the fuel tank allowing for a double isolated bracket which in theory should work well, however in reality it turned out to be too much flex and when fitted the whole bracket then vibrated and bounced on the top of the fuel tank. The revision of this was just to remove the lower two rubber mounts and directly bolt the bracket to the tank, so no flex within the bracket, but the pump is still rubber mounted to the bracket to help absorb the noise. 

I need to order some fuel hose and hose clips etc… then I’m going to pop 20lt of fuel in the tank and set the pump away. This will help flush the tank and lines of any sediment, not that there will be much as I have already cleaned everything and sealed it once done and will give me a better idea of how loud the pump will be when driving…. Hopefully not as bad as the test run in the video below. 

So next up then is just to make and fit some fuel pipe etc.. which I need to order and then that’s one step closer to running the engine. Another good step forward!

Diff-icult Customer

 

Well I have made some progress with the build, but unfortunately in order to do so I have had to completely rebuild the back end. It’s my own stupid fault really as I presumed that because the differential wasn’t loosing oil before it was removed from the donor car that it wouldn’t when reinstalled….. I was wrong. 

When removed from the donor car the diff was dry (not loosing fluid) the breather was clean and the output and inputs all felt really smooth…. So a quick cosmetic refresh and ready to go….. not! I filled the diff with oil a few weeks ago and within hours it had started to weep past the input seal and start covering the floor with EP90 oil. I am however one of those weird people that loves the smell of this thick sticky oil, so not all bad. 

I decided to rip the diff out again so I could replace all the seals, input and output. Despite it only leaking from the input which “could” have had the seal replaced in situe by just removing the prop shaft and input flange, however i now may as well replace the output seals and bearings also, so out it comes.

The removal of the diff is also a total removal of all suspension and leaf spring along with pretty much everything on the back end… so I have been a tad miffed having to do it. It would have been so much easier to have done this months ago before the body was fitted. But with the diff eventually out and on the bench I soon discovered that it is definitely not the diff from the original car… as the input flange nut is castellated, and on the late 1500 Spitfires it should be a solid nut with a dust cap cover… learning and discovery time. I continued to strip all the bearings and oil seals out of the diff housing and clean everything up. The issue now is ordering the correct replacement parts… many scenarios could be present for this diff, for example it could be an earlier housing (round input flange and castellated nut) with later 1500 internals so a mongrel as such. It’s definitely a 3.63:1 ratio (later mk4/1500) as I calculated that before stripping the input and output shafts. But it’s important to know exactly the ID as the mid production mk4 spitfires changed the diff slightly using different oil seals and bearings. 

Another lesson learned from this escapade is that I will not be using Rimmer Bros again for anything. Whilst they have a very comprehensive parts availability and platform for sales, the customer service and order processing is nothing short of shocking…. whilst not particularly on this order specifically the quality of some parts supplied is way short of acceptable. I won’t bore you with details but in a nutshell I placed an order on a Monday mid morning, all parts in stock, and payment made. Nothing delivered by Wednesday so a courtesy call on Thursday morning to check status. They apologised and said their had been an issue with the dispatch and they promised next day priority upgraded delivery so delivery now Friday….. and guess what it wasn’t delivered until the following Monday…. Tossers. 

I am however skeptical with anything I’m told over the telephone from someone clocking on and off for minimum wage, so I had on the Thursday (after chasing the order) placed a duplicate order through Moss which was about £8 overall more expensive (general price against Rimmers supposed trade price) and on the Friday the Moss order was delivered…. Great stuff! Rimmer Bross can just fuck off now with all future business from me they are a shower of shit, and for you chaps over in America that use Rimmers for all your British car parts, you should definitely use a different supplier… Moss, Canley Classics or even EBay… pay more get what you want/need. Don’t use Rimmer Bross. 

So with my contingency supplier out performing a market leader I was able to spend a weekend rebuilding my diff. I had taken the output shafts to work and used the press to push the new bearings on…. So easy to do with the right tool. The oil seals are a fairly low friction push and seat nicely with just a little hammer tap. Then I started to fit the output shafts back into the diff housing. I used a thin smear of RTV to seal the flange plate 100%. It’s rare for the output shafts to leak, but prevention is better than cure this time around. Once these were done I moved onto the input shaft. The oil seals here when removed was a metal circumference unit which is now superseded by a fully rubber unit. Still it’s the correct seal for the diff as the earlier diffs had a slightly smaller diameter seal. 

I refitted the input shaft and nut, which was torque up to the same paint marks I made on it just before it was removed then a new split pin… and after filling with more smelly sticky oil it was left to sit at an angle for a day or so on the bench.  Happily by the next weekend there was no signed of any oil getting past the seals and it was all rotating smooth and cleanly so start to rebuild the back end…. Again! 

I also since my last update received an email from Mick at Fiorano to say that he got his project car registered and mot’d with a quick home inspection from a DVLA representative. That is fantastic new so massive congratulations to Mick for that!… but it made me check further my own car…. And I’m glad i did. Mick said the DVLA only really wanted to check the chassis number and engine number. So I also checked mine….bugger. The frigging engine which was in the donor car and is 100% a 1500 engine which has been fully rebuilt, is not the engine number on my V5….fuck. 

When rebuilding the engine you can see from this photo that after the engine number the machine shop have stamped a 6 digit number that refers to the warranty with the head skim etc… that I paid for. So now I have written to the DVLA and sent them my V5 requesting a change of engine number. This could be an interesting avenue to go down, because normally they will want to know absolutely everything about the engine and its origin and have this verified through official channels. However I have pleaded with them to utilise all the information with the public domain to confirm the engines specifics. 

The engine number dates it from a 1979 MG Midget as opposed to a 1981 Triumph Spitfire. They both used exactly the same engine and gearbox setup and the engine parameters are identical, same compression ratio, same cubic capacity, same carburettors and most importantly for nowadays the same CO2 output…. Let’s cross my fingers and hope that all this information which is available online is sufficient for them to amend the V5 to the actual engine I physically have in the car…. And to be fair “was” in the car when I bought it. I feel this is potential going to escalate slightly but I’m sure we can work something out, after all I’m trying to do things correctly and keep everything above board. I could have just flattened off the engine number and re-stamp the block to match the V5, but I would have lost my warranty stamps for the machine work done. 

Fingers crossed for the next update. 

Clamping Down On Power

 

This is really just a quick one task update…. However it has been a full days work to fabricate and fit. I want to fit the battery for the Spyder in the boot. This will help balance the car a little and add some much needed weight on the transverse rear spring, helping with the wheel camber. 

My idea for the battery tray/clamp is just a simple fabrication made from some 25mm angled steel. I firstly just measured up the battery and gave a little extra for potential future replacements being slightly different base size, then made up three sides cut on a 45degree to keep it nice and square. Then I welded an off cut of some flat bar towards the front for strength and rigidity before moving onto the clamp. 

The front section is cut so that it will slide in and out of the side angles and can be torqued up using some M8 bolts through the front onto some retaining nuts welded onto each side section. 

Then with the basic frame made I added some bits of round bar on the front length and back to act as the clamp against the base of the battery. It has all worked out exceptionally well really and when tightened up it really gets a good grip on the battery nice and tight. I tarted it all up with some black paint to keep it all looking nice then moved onto the boot floor and making a suitable fixing position. 

The boot floor is literally just fiberglass which is strong and solid but does/will have some flex to it when rolling down the road. I wanted to beef everything up and give a good solid base for the battery clamp. I simply used a bit of flat bar steel which has been drilled through to two supporting brackets under the body tub which are fixed directly onto the end of each chassis leg. The I removed the battery and welded the battery tray to the supporting bar on the boot floor. 

A quick test fit of everything to check clearances etc… then I did a final fit with a good used of some PU bond on the bottom support bar and the battery clamp flat bar. This will help further holding it all down, and also help absorbing any vibrations that could be irritating when driving. 

Overall it’s all really good and strong and holds the battery solid as a rock… which is exactly what I wanted. 

 So yes only a small update, but a full days work and another job ticked off the list.