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My friend and I spent some time at the weekend welding the first exhaust manifold together. It's not quite complete yet but the bulk of it's done. We've still got to complete the lower half of the manifold before we can consider this side done. It was tricky avoiding the steering shaft but I think we've succeeded so far, and as a bonus, it even looks like it should flow relatively well.  And then, it's the same job all over again for the passenger side. Luckily, space is not quite so short on the other side so it should be somewhat easier, relatively speaking.

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If you build it, they will come

Since the last update, I've taken the engine out again, removed the rear axle & got the car back up on the rotisserie so I can weld up the hole in the transmission tunnel. It came out quite well to be honest. It's welded in the same way it is done by the factory, with the same layout of panels & the same style of seams. You'd barely know it's been fixed.

I've also spent some time getting the rear-to-front water pipe created. This was another of those things that appears like a simple job, but once you get started you realize that what's actually needed was a lot more intricate than you imagined. Anyway, I spent more time on it that I would have liked but it's created & now needs final welding.

I made some progress on the exhaust manifolds too. I spent ages working out how to join the collector section to the main manifold section. As usual the visible progress doesn't reflect the amount of work put into it.

This week I hope to complete the brake lines under the car and I'm tempted to also complete the fuel lines whilst the car is in the air & accessible. I'll then get the water pipe welded up & get the engine back in the car. I can then complete the drivers side exhaust manifold and start on the passenger side.

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If you build it, they will come

The thought process is often a long and painful one...

I presume that the factory routing for the coolant pipe was completely different, added advantage that the exhaust will now double as a pre-heater 🙂 . Are you able to pressure test the pipe before hane to check your welds as I don't think it is something you would want to find is a problem later?


If it ain't broken don't try to fix it as if you do it will definitely break

The factory routing was similar, but the pipe came out further in all directions. I have a lack of space so needed to tuck it in closer. And yes, I plan to pressure test it. I thought I might try the air compressor and a water butt.

If you build it, they will come

I decided to focus on some other jobs this evening. My friend lent me his brake flaring tool and it's MUCH better than my cheap one. It does the "universal flare" the same as Moss use on their brake pipes. I started with the front to rear pipe. It took me AGES on Google to work out how the brake pipe is meant to fit on the later model MGBs. Seems the pipe routing is different to the earlier models. I got there in the end though, but I did have to make a fancy bracket for the flexible brake line to attach to (when I actually order one). I've also realized that I've plumbed the axle incorrectly so I'll need to fix that at some point too.

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If you build it, they will come

I've not updated in a while. This has mostly because progress has been slow partly because of equipment failure but mostly due to me being dissatisfied with a job and having to do it again.

Anyway, I have actually made a nice bit of progress but I think I'm a week or so behind my schedule.

I removed the engine again, removed the rear axle & got the car back up on the rotisserie.  I could then rotate the car and plumb in the dual fuel lines from front to rear with 8mm copper tube. I've also made the front to rear brake line & re-made the axle brake line because I routed it incorrectly when I made it the first time. The battery cable is running alongside the fuel & brake lines. I've routed the wiring loom inside the car like the RV8.

I then took the car off the rotisserie, put the axle back on & got the engine back in. I then spent some time making the passenger side exhaust manifold. I'm really pleased with how it turned out but I've not put many pics of this up because I'm not too proud of the welding. It's welded properly but doesn't look nice. This is because I used my mig rather than the tig (which was broken and in for repair).

I spent ages trying to perfect the rear-to-front water pipe but I'm not happy with it. So, I'm going back to square one and making it again in a slightly different way.

I did, however, get a high pressure fuel pump into the tank. I used a unit from a Subaru Impreza sti. This should have plenty of flow. It had the advantage that I could cut down the length of it to suit the MGB tank which is surprisingly shallow. The disadvantage is that it doesn't have a built in swirl pot and the tank does not have baffles, so I could get fuel starvation if I let the fuel level get too low.

Next jobs are to:-

  • Weld a v-band flange to each of the headers & make the front part of the exhaust system, not forgetting the o2 sensors
  • Plumb in the engine wiring loom to the rest of the system using an auxiliary fuse box
  • Plumb in the fuel pump to the fuel hard lines with some flexible hose, via a filter
  • Plumb in the fuel hard lines to the engine
  • Remake the water pipe
  • Alternator to starter motor cable

My target is to have the engine started in August, with or without an exhaust.


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If you build it, they will come

No pics for this update I'm afraid but I have been busy with lots of jobs:-

  • Mounted the rear shocks. For now, just the standard Armstrong shocks. At some point I'll replace them with some telescopic adjustable AVO shocks that I've got, but I don't want to change too much in one go, especially before the 1st MOT
  • Fitted the fuel tank. It's now ready to be plumbed in. I've got all the rubber hose & hose clamps that I need. Just need to mount the fuel filter first.
  • Wired the fuel pump in. It's wired directly to the Omega fuel pump relay that's controlled by the ECU.
  • Wired the ECU in via a secondary fuse box that I've mounted under the dashboard. Luckily this ECU is real simple to wire in. The engine harness is self-contained & all it needs is permanent live & switched live. I've wired the "check engine" light into the charge light on the dashboard for now. I can put the ECU into "blink" mode so it will flash this light to tell me what fault codes it has. Currently it's telling me it can't see a crank signal (because the engine isn't turning).
  • Replaced the cam cover gaskets so they no longer leak 🙂
  • Replaced the oil filter & filled it up with fresh oil
  • Wired in the starter motor cable & starter solenoid wire. The engine now spins when the key is turned!

Next job tomorrow is to plug the engine harness back in & spin the engine again. Hopefully the ECU will notice the engine is spinning on the starter and engage the fuel pump. This ECU is weird in that it doesn't prime the fuel pump when you first turn the key. Apparently it expects to see a signal from the crank sensor first. So tomorrow I get to know if the ECU is likely to allow the engine to actually start. My plan is to have the engine started by the weekend - just for a few seconds to verify that it actually works.

After that, the engine will come out again and the rear-to-front water pipe re-made and re-fitted. I wasn't happy with the one I made previously so I'm going to make it again. I have some v-band flanges to weld onto the headers and then I can consider getting the front part of the exhaust system made.

I've also got new front wheel bearings to fit into my hubs. I've got brand new V8 brake disks & brand new Princess 4-pot calipers to fit. I just need to obtain the weird metric/imperial bolts. Then obviously making and fitting brake pipes. I have all I need, so it's just a case of doing it.

I think the only major part I have left to buy is a custom propshaft.

There's light at the end of the tunnel. Hopefully it will be drive-able in a few months. It's a long way from being finished though.

If you build it, they will come

Small but important progress tonight. The ECU saw the engine spinning & turned the fuel pump on after a few revolutions. This means that the work I did to remove the immobiliser actually worked! I was even more pleased to see it running the fuel pump at 8v rather than 12 which means the ECU is also controlling the pump speed depending on fuel requirements. I'm confident this is going to run before the end of Aug.


If you build it, they will come

Got the fuel pipes connected up today front and back. One step closer to 1st fire up!

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If you build it, they will come

Not quite ready to start the car yet because I'm waiting for a rubber seal for the water pipe. This is a Vauxhall main dealer part that is being shipped from Germany. Hopefully that should be here soon & we should be on for an engine start later this week.

I've also finished wiring in the engine harness. I've documented the pinouts below. This is for an Omega engine loom. If you're using a Vectra loom, this is documented here 

The engine loom comes with 2 large round connectors. One is brown and the other is white. Most of the stuff you need is on the white connector.

Connector Pin Connects To Description
X3 White 1 fuel pump Power output to fuel pump
X3 White 2 coil pack 12v power input for coil. Should be switched live
X3 White 3 ECU pin 55 KW82 communications bus connection. Wire this to an OBD2 connector on pin 7 and then you can use OPCOM or VauxCOM to talk to the ECU
X3 White 4 ECU pin 13 Leave this pin unconnected but make it so you can easily ground it. Grounding this pin causes the engine management light to flash with error codes
X3 White 5 ECU pin 22 Engine Management Fault light in dash. This is a ground trigger. This means that you should wire a light on the dashboard so that the light has 12v and uses this pin as ground. The ECU will then ground this pin to complete the circuit
X3 White 6 Reverse light switch
X3 White 7 ECU pin 9 used for immobiliser request/acknowledge. I'm not using this at present because I removed my immobiliser but will use this in future.
X3 White 8 Reverse light switch
X3 White 9 NC Not needed
X3 White 10 Traction Control, ECU pin 54 Not needed
X3 White 11 Coolant Temperature Sensor The engine has 2 coolant temperature sensors. One is for the ECU and this one is for the dash. I have no idea yet if this will feed the Smiths gauge on an MGB dash
X3 White 12 Not needed
X3 White 13 Tacho, ECU pin 43
Tachometer pulse. I have no idea yet if this will feed the standard MGB tacho
X3 White 14 Traction Control, ECU pin 38 Not needed
X3 White 15 ECU pin 27 ignition circuit switched 12v input to Motronic ECU
X3 White 16 Not needed
X3 White 17 NC Not needed
X3 White 18 NC Not needed
X3 White 19 NC Not needed
X3 White 20 NC Not needed

In addition, there's a large green plug with a single wire. This is the main power feed to the engine loom & should be unswitched 12v live.

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If you build it, they will come