The Black Pudding

The original build diary text and photos for the first known Omega GM V6 engine swap.

The Black Pudding

A while back I got a 1979 SE6a auto in special order black, this was bought with the soul intention of being entered into the Practical Performance Car magazines £999 challenge at Mallory Park at the end of May. I decided the car needed a little more power and would suit a more modern engine well.
The cheapest power I could find was the 3.0L V6 Vauxhall Omega's, these have 210BHP and 200lbs/ft. The Vauxhall engine is a nice compact engine having a 54° V is only a little wider than the Essex. It's also exactly the same height and a little shorter, it's also lighter having aluminium heads.
A standard 3.0L Omega weighs 1550kg or 1.7ton yet with this engine it does 0 to 60 in 8 seconds and keeps going to 150mph!


I managed to get myself an ex-police Omega estate for £270. The police spec comes with a more rare 5 speed manual box, this is a real bonus. It's a very short box with an easily adjustable gear linkage that can be made to fit the scim with little hassle. I am also amazed at how light this gear box is. I weighed it having single handedly lifted it out of the car through the engine bay. This box is only 40kg or 88lbs in old money. That's got to be a huge saving over the old auto.


Next up.
Because of the amount of cooling this engine needs the spare wheel is going to have to reside in the boot.
The keys and immobiliser are going to be kept. An immobiliser is a nice thing to have on the Scim anyway.
There's also the compressor and vacuum air pumps to transfer, and if I want the omega speedo to work in the scim I'll need to transfer the abs computer and sensors. I've also got an ecu reader coming 


Came up with an idea for cheap air ducting to the filter box. Gutter pipe, the pipe it's self came out of a skip and the 4 fittings if I need them all cost a fiver.  


I’ve done a quick check on the EML flash codes, came up with:
SAI - Not connected yet
EGR - I haven’t connected the flying saucer
AFS - not connected properly
Immobiliser - didn't have the key close enough on the first start up, that code should clear itself.
Well I've added a few relays to make the ECU happy, and it now runs without the EML flashing on and brings up no fault codes. Result!
Now I've got the induction piping sorted it runs even sweeter. That GM power steering pump runs the steering rack lovely as well, the pipes were even in the correct place and correct size to bolt straight on.
Most of the loom required goes with the engine, ecu included, there are only 3 connectors that link it to the car. Of those three connectors you will require about 12 wires plus the 4 big fuses in the engine bay. Off the top of my head they are:
Ignition Pos 2
Ignition Pos 3
Permanent live
RPM signal for gauge and immobiliser
Temp signal for gauge
Oil pressure signal for warning light
Battery charge light
EML signal for light
EML flash code wire
Immobiliser signal
Secondary air induction relay wire x2 (just to keep the ecu happy)
You will also require the immobiliser fixed around the ignition key switch and the key.
I may have missed a few, once it's complete I'll have to produce a more comprehensive guide.

Other than that I've completed the engine bay electrics, made and mounted the battery, finish the bulkhead and painted all the fibre glassing that I had done, and welded a patch on the chassis.

MOT tomorrow (Friday 15th) at 9 am, ooooohhh

MOT tomorrow (Friday 15th) at 9 am, ooooohhh
The MOT station have apparently been preparing for my arrival ??????????
I'm not sure if this is a good thing or bad thing. Just what prep do they need to do???

It passed first go with no advisory's

Oh forgot to add,,,, flippin heck it shifts.
A little acceleration test, keeping it about 3000rpm and it spins the wheels when you change to second and third. Scary stuff.
So I can happily report it's proper rapid. I used to think my VW Corrado G60 was quick, but this would leave it for dust.
Does anyone get the impression I'm just a little happy with it?

2009 PPC £999 Challenge

Well I'll be off to Mallory Park just after lunch, thought I'd give it a quick tart up with some polish and back to black. 


I'm really looking forward to the challenge at Mallory.
I'll let you all know what happened, on Sunday eve.
If anyone else is going to Mallory come over and say hi, the car will be in the paddock area or on the track all day.

Well, firstly I'm loving that car.
What a great weekend, what a lovely friendly atmosphere between all the £999 competitors. The challenge went a bit pair shaped, not on my part but on the set-up of the £999 challenge, they didn't allow enough time to do it properly between track sessions.
There were 39 entries in total, we didn't have time to do the standing 1/4 mile which was a shame as that was the only part I thought I'd have any chance at. Instead the handling test and 1/4 mile were combined into a partial lap of the track.
The auto test should have been called rally cross. It was held on a gravel area. So I thought it best to forget the handbrake and use my right foot instead. Probably no such a good idea, my best time was 54 second flat. putting me 34th. Oops. That's the drivers fault not the car.
On the sprint things were a bit more promising, I managed 5th out of 39, so she pulls well.
PPC staff decided to call it void and have invited us all back free of charge to do it properly again very soon.
I also had 15 min's of track time and that was great fun. I absolutely thrashed the be-jesus out of it. I didn't trust it on the corners at all so was taking them slow, but on the straight it was awesome and passed everything that got buy on the corners. Pulling cleanly away from a Porsche 944 was most amusing.  I was taking the long corner in 4th then flooring it as it was still around 3000rpm, it was pulling 130mph down the long straight in 4th. Oh and the noise it makes under load like that is lovely.
Anyway I thrashed it until the break fluid boiled. I guess I should have replaced that as I have no idea when it was last done. I had to give up then as that was a bit hairy. Needless to say the cars faster than I'm capable of driving. I also cooked the crank angle sensor on the last few laps and it was reluctant to rev above 3000rpm, so I need to get a new one of them too. It's fine unless you get the engine hot and work it hard when hot. They are prone to doing that apparently.
I need to give it to someone who knows what they are doing to test it properly for me.
As soon as I get some pics of it I'll post them on here.
I guess that's given it a good shake down, along with the 300 mile round trip to get there and back.
Oh also forgot to add, PPC magazine are going to do an article on it, I need to contact them again in the week. I also ended up having to go up in the commentary box and have an interview about it. How embarrassing is that. 


I've spent so far £858, I can sell another £80 so that would give me £221 max remaining funds.
A huge set of super sticky tyres on the back would be the best improvement for the £999 from what I can see of it. That or a miricle of an LSD for that money. A set of second hand adjustables would be good but it's traction in a straight line that's going to make it I think.
The three tests should be:
Auto test
Standing 1/4 mile
Sprint around a hair pin
All the times are added together and the lowest wins. So the most amount of time can be saved on a good auto test. That's the part I'm useless at, the auto test is more skill than car. Even the PPC Rolls Royce beat me on the auto test. Though I did beat the 750i V12 BMW and Jag V12. Never have there been so many out of place cars on one auto test.
The clever cars from what I can see of it are Nitroused metros and fiestas and the like. They have the advantage on the auto test then the nitrous comes in on the drag and for the brave also the sprint. As long as they can put the power down there away.
That track session yesterday really opened my eyes to what I've created! Nothing except single seaters passed it on the straights, though it was mainly chav-mobiles going round. The Porsche 944 made me laugh though, and a modded Cav that was really trying hard. 

Back Home

I've got my head buried into Lambda sensors at the moment trying to fathom which one is playing up. I know it's sensor 2 but trying to work out if that’s the left or right at the moment.
I stuck my pc oscilloscope on both sensors at the same time in the end and instantly found the left hand one to be at fault, a steady 0.6V
All I had in the garage was an old one from a Vectra. Trouble was it had 4 wires while the one's on the V6 have 3. A quick google found the way to convert it into a 3 wire type. I fitted it and re-monitored it with the scope. Below is what it looked like, the original RH one is red channel 0 and the new LH one is green channel 1.


It's slightly lower on voltage (0.1v) but the ECU seems happy with that, it also seems to switch more regularly so perhaps is a little more sensitive.
The car now pulls even better and idles more smoothly, I thought it was smooth before.
The old one was stuck telling the ECU that it needed more fuel so when hot and really working the car was over fuelling hence being reluctant to rev over 3000 every so often. It should now be even more economical.

A test drive today shows all noise issues fixed so there's a result.

What a lovely circuit Curborough is, we all had a great day there Friday despite the weather. The morning tipped it down but in the afternoon the sun came out and it was lovely.
We all done a drag race in the wet from the last corner back down the the finish line. My best was a 11.37 in the wet, the best for the day was a 10.24 set by a Skoda Rapid on NOS. Neil's SS1 turbo done a 10.93
We all then started the sprint, which was a double lap of the circuit starting and finishing at the line. The front wheel drive lads were really struggling in the wet. The best I could do in the wet was about a 1.19.52, and most of that was sideways, I think I drifted the whole circuit.
It then rained so hard the circuit started to get some big puddles so we called it off for lunch, and managed to cram about 30 of us under one gazebo. In the afternoon the rain had stopped and the sun came out. On my first dry sprint I knocked 10 seconds of my best wet run and came in at 1.09.11, I couldn't get this much lower and done my best at 1.08.89, this put me back in 18th out of 24 runners. I think I need more practise at this, I've never really done anything like it before. Though less than half a second faster would have moved me up to 14th over all, it was that close between everyone. Neil managed a very competitive 1.02.98 to put him self 3rd over all, well done mate. Best time of the day was jointly set by an MX5 2.0L on nitrous and a Honda Prelude at 1.00.32
I had a great day there and what a mixed bag of competitors, less than a grand motor sport is so much more fun.
It all went a bit pear shaped on the way home though, the fuel pump gave up on the M42. I think there must have been some rubbish in the tank that got stuck in the pick-up pipe. So my arrival home was on the back of an AA truck.

Back at it again, this time concentrating on the speedo. As some of you will be aware I've been using a GPS as my speedo, so yesterday I started to look at what was required to get a speed signal sorted. The first thing to do was establish what the signal was supposed to look like and how it was affected by the speed.
To do this I used the Omega speedo as my Ginnie pig and found that the speed signal to the speedo is held at 12V, then taken to ground every time the Omega wheel sensor passes a tooth on the axle.
So I quickly rigged up a BC547C transistor to switch the speedo signal to ground then made a program and used my laptop to emulate the signal. Amazingly it worked first time and I could control the speedo from my laptop.


Speed to frequency is as follows:
So it's linear that makes life much easier as when I make the signal conversion control box the maths needed in the processor will be simple.
I even clocked up 18 miles sat on the drive.
Next job is to mount up a sensor on the prop shaft and work out the conversion formula.

I want to fix the omega instrument console permanently in the car along with its digital display and trip computer, to do this will require modifying the dash top a little, now as this is warped and cracked I wasn't to bothered. On looking at the rest of the dash I decided that was in a poor way and up to usual Reliant interior standard. To this end I've gone for a complete redesign but keeping the Reliant "look". I spent a good few hours down my local scrap yard with a tape measure and tool box. I've come away with a complete Vauxhall Corsa heater unit and the control panel with all linkages and associated wiring. I've also got a Rover 400 series fuse / relay box. While down there I noticed that Alfa Romeo 156 seats are very nice and also very narrow, they look about the same size as the SE6 ones, sadly no tilt mechanism though.
Anyway, here's a quick pic of my plan with the heater sat temporarily on the passenger seat.


I'll make up a steel dash skeleton then use 10mm square steel mesh to complete all the contours needed, then fibreglass, plastazote 3mm foam, and leatherette. It will be made in the same way as Reliant did, so a separate top panel, centre panel, and side panels. The main dash and side panels will be tan leatherette with black instrument panel and black centre panel.
Once the dash is done I can get on with replacing the horrid carpet and generally tarting the interior up a bit.

It's ended up exactly as I wanted and should look great covered in tan vinyl. It's hard to get a photo to show the radius's and curves correctly, I've also sealed the dash in fibreglass resin now so that there is a good base for the contact adhesive and foam / tan vinyl.
It was my first attempt, but to be fair I had a good fiddle around with the wire frame and mesh until I was happy with the shape, it's only once it's fiberglassed that your stuck with the shape. It took a whole day of body filling, then sanding, then body filling, then sanding, etc etc.

I now have the rubber paint on order that should arrive over the next few days, I'm interested to see just how good a finish it produces.
I've managed to buy a full Scimitar leather interior for it in the same colours, and replace the leaking heater matrix that the Corsa heater had when I tested it. I've made a template for the sides of the centre console and a radiused part that keeps the lines of the Corsa vents right thought the dash therefore making it all look more complete. I've temporally fixed the leaking sunroof only to find the wiper's are letting water in now grrrrr. Still at least this is before I put a new carpet into it.

The Sale

Owing to lack of undercover space and currently time, I am offering for sale my SE6a Scimitar fitted with an Omega 3L 24V V6 and 5 speed manual gearbox. I guess you could consider this a rare opportunity, and I may yet change my mind and build a workshop for it.
Viewing this is I'd say essential, as it's been off the road for 3 years sat on my drive, it still starts and runs fine, but this is in no way a completed project. From my brief look around it I'd say that for an MOT it would need some new tires and more than likely the lights sorting out again as I know how temperamental these can be. Also some finishing off the interior to make it drive-able. Body wise the sunroof leaks and the paint is crazed, the interior is shot,,, however, I have a complete spare cream and tan leather interior in the shed which goes with the car, you'd just need carpet and to sort the dash / center console. It has some custom dash I started and also the original that would bolt straight back in. The only thing requiring sorting would be the heater, as I sat the engine back as far as possible for handling.
This car for those that do not know, was built for the Practical Performance Car 999 challenge back in 2009, PPC magazine liked the car so much they ran a 6 page article on it in the October 2009 edition, it also seems to get the odd mention even now.
I'll also include the cam belt change tool kit that cost me £100 as the Omega Haynes manual (also included) states 40K miles or 4 years for the cam belt change period.

Price wise I am open to offers, or I keep it and finally get it finished, what it cost to build was no secret as it was in the 999 challenge so the total sum of the parts had to be under £1000.

Needless to say, it eventually found a new owner...


The contents of this website are purely a reflection of my own experiences and knowledge gained whilst working on my various projects. Anything you do based on what you have read here is done so entirely at your own risk.
Personally I wouldn't trust someone like me with a lawn mower! You have been warned! Flapper-bat!

Made with ‌

Website Software