1974 Turbocharged MGB GT (MX5 Swap)

Nice work! the engine looks to fit quite nicely in there, wiring looks a bit of a nightmare though I shall definitely be keeping an eye on this

It Moves!



Last weekend seemed to be one of the most productive in recent weeks.
Clutch adapted.
Throttle cable made (new skill learnt there).
Wiring re-routed and tided.
Switch Panel installed.
New brake lines made and added.

As you can see it's rough running, the exhaust is very much a "Work in progress" and thus the Lambda is not getting a correct signal. Also the return fuel line, which is actually the original engine feed for the B series is causing some issues. But it runs and moves Chuffed as a pig in s**t.

Wheeled it out last night for a few more shots.
I have noticed that the arches are ruined, this whole install has been done without removing them thus leaning has caused some cracks. However as my mate says it does add to the look, I will probably repair them at some point but its way down the list for now.

My apologies for the picture quality, my 14MP camera phone seems to imitate a 1.5MP camera.

A little more done this weekend, namely a test drive on the garden.

I have managed to wire in all the dials (apart from speedo and oil pressure), so its getting there. Also finished off the switch panel and illumination including external lights.
With the whole project I want the ability to be able to go back to standard, so I have kept the MGB and MX5 wiring separate...only 3 wires come from the MGB end to the MX5 power feed (Tacho, Main fuse feed for lights, back light for new dial). This also makes fault finding a lot easier as I don't have to look at the Lucas electric for anything MX5 based.

I still need to run a dedicated return for the tank, currently it uses the original feed but this seems to be causing issues as its struggling to return. My guess is due to the return feed being placed at the bottom of the tank, so its struggling to push past the fuel. The MX5 method just drops the fuel in at the top of the tank, so I will connect this back up and cover over the original.

The MX5 heat shield was in a sorry state so I decided to Wrap the manifold, I know this always causes a debate but I like the look so who cares! I then decided to take it on a test drive around the back garden, as you can hear from the video it has a hole in the temporary exhaust, the hole is just before the Lambda sensor and its also causing the ECU to raise the richness (The manifold was glowing bright orange after this test run), but it did motor along and as you can see it wants to go sideways :-).

Overall it's getting there, the Prop is exactly the right length but I need a smaller diameter really (MX5 props are quite a bit thicker than MGB ones). I'm pleased with the power on the test run even though its running like a pig ATM.

Next up is sorting the Exhaust, getting a speedo cable made and generally tidy it up.
I ideally want to then remove the engine and tidy/repaint the bay as its taken a beating upon doing the install.

I was not going sideways...honest..



It's about done, just waiting on a new Rad cap as a 15lbs one is needed not 10lbs like fitted to the GT's.
Front valence to refit, wire in the horn again and it's MOT time :-)

Seconded. Brilliant stuff, I think you're right, this will become a very popular conversion, always good to be a pioneer

Little update from this weekend.

I am mainly getting the small jobs buttoned up, and replacing components that we know have failed.
Upon the last test I noticed she is running very lean, on the MX lump it usually means a faulty connection to the Water sensor or the Lambda. I tested the Water sensor and its output was low but the wiring was fine, so instead of messing about I replaced it and got a new Lambda. These have been fitted but the cars not been tested due to the weather and the fact I ripped the garden up the weekend before :-).

The Radiator venting too early looks to be solved by putting a 15Lbs cap on, but I could not test the fan as I broke it removing the lower radiator hose (fitted a new fan last night). I am hoping that and the new sender unit will sort the issue of the fan as we know the ECU is getting a temp signal and its activating the relay.....

Most of the wiring is now mounted behind the centre panel I made, but you could see most of it from a side on view so I decided to make some side panels (this area would usually be covered by the standard console but I am going for a minimal look). Whilst I was doing this I decided to re-cover the centre section too (It was an OK job before but parts were bugging me), and fit a new temperature and oil pressure gauge (Oil pressure did not arrive so I filled the space for now with a old tacho again). All of the switches in the cluster have been replaced (the others were made from cheese I swear) and the whole centre section looks more sorted.

I will take better pictures this weekend but you kinda get the idea.



I was going to refit the front valence and external oil cooler, but noticed a small amount of welding is required (old repair rusted out), I left the valence here and had dirty thoughts about extending it down like that. Of course it would last about 5 mins on the open road but does look a little cool.


I'm hoping to get the last bits done and book her in for the MOT in Feb, oddly enough its only just lapsed :-).

Cheers.

Love this car. Keep going, you are very nearly there. Not long until 'one of the coolest mgbs evaarr' status is achieved

Great work & good luck for the MOT

handheld diagnostic readers are pretty cheap on fleabay these days (or borrow one off a mate, that's what i do ) without the fault codes it could be a lengthy diagnosis