It took 2.5 years to build the car and pass SVA (now IVA) and a lot longer to get to where it is now! To see the Sportster out on the road have a look at one of the videos here.

During 2008 we rebuilt the BMW engine from 2.5 to a 2.8 creating an M20B28 stroker engine. It uses the crankshaft from the later BMW M52B28 and the conrods from the M20B20. Not much more work is needed other than a clean up, slotting those bits together and a crank spacer. To read about the engine build click here (very picture heavy!)

In March 2009 it was painted, a full set of images is here.


Clutch Hosed

Sometimes you shouldn’t touch a thing, but in this case it was a good thing. Sportster clutch pipe from the reservoir to the master had a split so it leaked everywhere put low fluid light on – outside the cabin luckily.

So I thought I’ll fix that and also change the adapter into the master cylinder, that broke a while back which I patched with a hose clamp in a Halfords car park, so it’s been on the list for a while.

Took the master off (bolts in the wrong way so had to take the entire mount out – this must have happened last time I had the pedal box, or when we made the clutch cylinder mount, out as you can’t get the bolts in that way round normally. It turned out to be a good thing as one bolt had backed almost all the way off so it was a good catch to fix it.

While moving the master cylinder I broke the hard line connection on the end of it, turns out it wasn’t a great flare I made years ago, so was another good catch. Got a much better hydraulic flare tool now so put a double flare into it. Still a bit fiddly under the dash with limited room but much easier than the old tool I used to use.

Installed the new hose adpater plastic tube into in the new adapter in the top of the master, installed a new feed hose for the brake fluid and reassembled everything.

Went to bleed the system, nothing came out the bleeder. Even with over 20 PSI in the brake system!

Took the slave cylinder off, cracked the host off. The worst grey rubbish you can imagine came out the pipe. The bleeder on the slave cylinder was ok, but the passage behind it was blocked up with some pretty solid gunk. With that cleared the system was good to bleed so stuck the cylinder back on the gearbox.

Bled the system after a lot of cursing and several rounds had a decent pedal.

Cleaned up went in for a bit to wash hands, came out – no pedal. Tried to bleed again, loads more air so turned out the master cylinder was hosed. Looks like it might have blown an seal inside which is where the gunk probably came from. The gunk then clogged up the the other end.

To be on the safe side, ordered a new master and slave cylinder, overnight parts from eurocarparts in Basingstoke! Lucky they had one of each in stock from pagid.

Fitted those this morning followed by 3 rounds of bleeding, seemed OK second time – enough to let the car roll pushing on the clutch, but couldn’t put it in gear when the engine was on. So one more clutch bleed and now it’s all good. Infact the clutch is better than it has been in a long time.

All because of a crack in a rubber hose!

The good thing was it was fixed so we were able to attend Classic Car Sunday at http://www.thedepartureloungecafe.co.uk/


Differential Bushes

The differential has been sqeaking and nods up and down under load so it was time to get some new bushes.

Both sets of bushes are from https://www.powerflex.co.uk/ – the main rear diff bush is the E30 188mm part – PFR5-300H from the heritage series.

The front two bushes are the same ones used on the front wishbones which is a Ford TCA bush; PFF19-102H also a heritage bush.

The heritage bushes are polyurethane same a the normal purple ones but in a darker OEM black colour.

Here’s a small video clip of the rear diff bush on video which shows the seperation:

Step 1 remove the differential, this was relatively straightforward. Unbolt and drop down with the jack.

Removed diff looking a little dirty, good time to give it a bit of a clean.

The rear bush – the middle part is separating from the outer part leading to excessive movement.

Removing the old ford bushes with the press

There’s some surface rust but overall not too bad.

Old ford bush next to the new poly bush.

Test fitting the diff hanger with the new poly bushes (some foreshadowing going on here)

Used the power saw to chop out the old OEM bush

Fitting the new powerflex bush, these always go in so easily compared to OE bushes.

This one has a big washer either side of the bush to keep everything in place. In addition to this is need two more small washers to space the bolt to the diff hanger (more foreshadowing, there 7 layers that need to line up here).

While everything was taken to bits it was a good opportunity to powdercoat the diff hanger with a fresh layer. Some of the original had flaked off and there was a little surface rust. Not much easy to clean up. Here’s the coated part baking next to the heat lamp to cure the powder.

Finished part cooling down, this is the ‘matt black’ finish which is still a bit glossy but has a bit of a rough texture.

Fitted back on the diff with the new poly bushes looking very shiny again.

So, the foreshadowing. This is after trying to fit the diff the first time. Couldn’t get the large bolts in on both sides. Ended up bending these hangers, so took the diff out, and both hangers. Bent the one that got messed up back into shape. Both got a new layer of powdercoat too. Re-fitting took a long time, it was easier getting the mounts back into the chassis than bushes into the mounts. However it took a lot of fiddling to get them seated in. This was with the rear bush held up with a screwdriver so it could move around a bit.

The new rear diff bush has a much tighter tolerance than the OEM one and required two washers either side of the bush. Took a load of fiddling to get all 7 layers (hanger, small washer, large washer, metal rod the bush sits on, large washer, small washer and finally the hanger on the other side).

Yes it did go dark while getting the diff back in. Here it is back in place.

The squeaking is gone, power transfers through the drivetrain smoothly. Overall bit of a pain but well worth it.



Engine and Gearbox mounting bushes

Recently the alternator hit the chassis when I changed direction, a good indication that the engine and gearbox mounts might need some attention. Unfortunately the alternator bearings were damaged due to this impact. I therefore ordered a new alternator (with the aim to rebuild the old one as a spare).

I then also changed the engine mounts & gearbox mounts. I used polyurethane from Duraflex (they sent the wrong bushes first time, but did swap them out after I sent them back for the right ones, did take a while before they responded to emails though so you’re aware if you choose to get some of these). The original engine mounts were supplied by Marlin so I didn’t have specific part references for them.

They are 35mm thick with M10 studs, the closest I could find were Land Rover Defender gearbox mounts. I ordered the ‘soft’ variant which is 70 shore. They had mounts for BMW gearboxes, went for the ’80 shore a’ ones which is the normal hardness option for the bush.

Land Rover gearbox mounts: https://www.duraflexpubushes.com/land-rover-defender-enginegear-box-mount-mounting–duraflex-urethane—-nrc9560-284-p.asp
BMW Gearbox mounts: https://www.duraflexpubushes.com/bmw–gearbox-mounting-257-p.asp

The engine is under much better control now, I get less oscillation / vibration into the front wings and feel better now when driving.

I also had two worn out cracking ball joint boots so I changed those too.


Gearbox Mounts

Old BMW bushes compared to the new poly bushes. The new bushes are a bit chunkier (same height)

Here’s the gearbox mount cross member – had to take this all the way out to get the new bushes in place, a little bit fiddly.

After some swearing the new bushes are in place with the cross member bolted back in.

As the new bushes are more chunky than the old one ones I had to use the deathwheel to grind down this spanner to fit between the chassis and the bush to hold the bolts when doing up the nuts inside the car.

Engine Mounts

Removed the bonnet and both side panels for this job:

Jacked up the engine after undoing the lock nuts until there was enough clearance to get the old bush out.

A comparison between the now deformed bushes and the new poly bushes. The studs are a bit longer on the new one so the engine needs to be lifted a little higher to get the new bush in (on the passenger / intake side)

On the driver/exhaust side the steering column linkage is in the way of lifing the engine high enough to get the bush out. It was much easier to take the 4 bolts out that hold the engine mount to the block and pivot it out the way.

Here with the new bush fitted and bolted down:

Alternator Change

Big ol hole where the old alternator was removed, added a small notch in the chassis here to allow more clearance in future.

I got the new alternator from https://www.schmiedmann.com in Denmark, mostly because I needed a glow plug control module for my daily and they were the only people in Europe that had stock at the time! The new one is very shiny!

New alternator in place, added a new v-belt while I was at it as the old one wasn’t brilliant anymore.   

Here’s the new alternator hiding away among intake and water pipes!

The really nice thing about the new alternator is that it charges straightaway after starting the engine. The old alternator needed you to rev up past 3000 rpm before it would start charging.

Ball Joints

These don’t last super long every few years I need to replace them, these were not damaged from dirt ingress yet so I was able to just change the boot (sourced from ebay ej-parts size 16/31/23). I did fit one new ball joint as I didn’t have enough time to wait for the boots to get it through the MOT this year so I was able to pick one up from Euro Car Part locally.

Yeahy rotten rubber (this is now an MOT failure, these might have squeaked through as they were not cracked all the way though, but it was time to change them):

One new ball joint fitted:

This ones pretty bad, but the ball part of the joint was still good.

New boot from ebay with the mounting hardware from the old boot

Reassembled, old ball joint with new boot:

Still to do are the differential bushes – the stock BMW M bush (from the Z3M) has a lot of movement, the centre mount hold is tearing out of the rubber. Additionally the ford TCA bushes used to mount the front of the diff to the chassis feel soft and are squeaking quite a lot. If you move the car by hand with a gear selected the diff does a nodding dog impression. I’ve got some poly bushes to install in the near future for that too.


High level brake lights and indicators

Installed a 3rd level brake light 9 years back as a ‘temporary’ solution to make it clearer when I was using the brakes. I’ve been meaning to install something cleaner that’s not partly covered by the spare wheel cover. I’ve also noticed that my indictors could be clearer, people don’t seem to see them. This is either because they are quite low or the angle makes it more difficult to see them.

I found some LED tail lights from the motor bike aftermarket made by Kellermann model Atto DF. There are versions that are brakes only but the ones I bought are tail, indictor and brake combined.

The LED lights are very small, but very bright.

Here’s one unit next to the regular rear lights.

Bench testing the lights – they leave bright spot in your eyes!

In order to mount these I dug into more of the motorbike aftermarket, ordering this bracket from https://www.hogparts.co.uk/ – this is a P clamp made by Kuryakyn, and a Kellerman Atto rigid mounting M8 x 20mm which fits nicely into the P clamp. The clamp mounts to my seatbelt bar which is 1.25″ cold drawn steel. The aluminium spacer is removed to fit on the 1.25″ pipe.

I also tried a Kellermann Bullet Atto extension 15mm to see what the lights were like a bit higher up – wasn’t needed to clear the spare wheel cover and didn’t look as good.

The M8 bolts that came with the Kellerman M8 x 20mm where silver, so I dug out some more compact nuts and powder coated them gloss black.

One came out perfect and one with a bit of chip, but you can’t see that when mounted.

Test fit with all the parts

The wires that come out the bottom are quite thin. To make these look nicer and protect them I covered them in shrink tube and zip tied them to the seatbelt bar and roll bar.

To get the wires inside the tub I added a hole and rubber grommet big enough to put spade terminals through.

The second stage of the projected required the entire boot area to be taken out so I could get to the rear wiring loom.

This is the exposed loom, I spliced into to the tail lights, indictor left and indicator right. There was already a cable for the brake lights, plus an extra 12v+ and a ground.

Put a PVC cover over the new wires, used shrink tubing and insulating tape to tidy up the loom. I added some weather sealed connectors at the other end.

From the rear car loom into the tub I created a small loom just for the lighting cables. I left the ground separate so at a later date I can use it for also grounding an interior boot light. The 4 pin is all the rear light connections.

I went a bit overboard and ran wires for the left and the right indictor to both sides – oops. Maybe some day I’ll need them.

So one of the wires on each side is covered up. I used coloured shrink tube to make it easy to connect the spade terminals together correctly.

I added a large hold in the side panel big enough to fit the 4 pin connectors through.

The final part of the process was to tie up the cables along the top of the tub so they are not hanging down. Then mount all the rest of he boot interior panels and boot hatch back onto the car.

The final result – nice and clear high level brake lights and as a bonus supplementary indictors.



Reverse a switch – upated brake fuild level warning circuit

On a 1988 car the brake level sensor works the opposite way around to a 2011. On the 1988 when the brake level gets low the switch connects the circuit and turns the light on. On the 2011 it is the other way around, a reed switch is close so there is power through the circuit until the fluid gets low and opens the circuit.

This presents a problem when you use a 2011 level sensor on a 1988 circuit. Fortunately there is a solution in the form of a relay. It needs to be a normally close type. Or one with open and closed contacts, but connect to the NC terminal. Normally closed means if no power is applied to the relay it is close.

The normally close part of the relay replaces the old level switch. This means when power is applied to the relay the circuit is open and the light is off. When power is cut the circuit closes and turns the light on.

Power is taken from ignition runs through the relay and the new level sensor. This means the relay is power as long as ignition is on and the brake fluid is full. 

The advantage of the new brake sensor circuit is that it will pick up low fluid but also any brakes in the wiring to the sensor.

Shiny new brake level sensor

New relay, normally closed. Pin 30 and 87a take the place of the old sensor, Pin 30 and 86 take power from ignition and are connected to the new sensor.

Used a ratcheting crimper to – highly recommend getting one of these as it makes crimping terminals really easy.

Couple more terminals, these go into the car’s E30 1988 circuit.

This handy relay holder/fuse holder combo makes it easy to change should the relay ever fail, or if the fuse blows.

Using a power probe to test the relay, it simulates the new level sensor circuit, with power applied the brake warning light is off, this would be the normal state when the car is on.

Power disconnected from the relay the warning light turns on – if the fuse blows, the brake level is low or a wiring breaks it will show the warning light.

All the wires added to the fuse and relay holder.

Zipped tied up into place under the dash where it’s easy to get to and service if needed.



Brake Fluid Reservoir / Expansion Tank

Recently tried to flush the brake fluid with a pressure bleeder. It uses a chain to hold a top on the fluid reservoir/expansion tank. That doens’t work at all well, didn’t hold well, brake fluid went everywhere.

On the other cars I look after there’s a screw on cap type that works really well with the pressure bleeder.

The reservoir that’s been on the car since building it was from Marlin, I don’t know what car it’s from but I can’t find an adapter for the pressure bleeder. So the next best thing was to change the tank for an OE BMW one that works with the bleeder.

The new part is from a 1972 BMW E21 BMW Part 34321112399 – ATE Part 03.3508-5851.3. It doesn’t come with a level sensor, for that I used a newer part from an E9X BMW part 34336774451. I had to modify the expansion take slightly to allow clearance for the sensor. It is about 0.5cm longer than there is room in the expansion tank, just meant chopping a small amount of the wall between the front/rear fluid chambers. There is a sensor specifically for the E21 tank 34321153157 but I wasn’t able to get one.

Removed this one, set it aside so the system remained closed while creating the mount for the new one.

Cut out an aluminium plate and added some riv nuts in the top to bolt the the tank to. Made sure the tank is level fron to back.

The rear bottom is the same mount as the old one, drilled a hole for the front riv nut. 

Transferred the clutch and two pipes over from the old tank to the new one. Added some clips to be sure they’ll stay there under pressure.

Added a new plug on the end of the level sensor wire, this one is off ebay from an E46. Could figure out the part numbers for the plus so that was the easiest way to get one.  

Clearance check for battery.

Battery back in, lots of clearance for the bonnet.

View through the louvers

Fluid change should be relatively clean and easy next time!

Engine Work

Fuel Injector Rebuild

In 2005 when we build the car we had the fuel injectors out, added new o-rings and gave them run in an ultrasonic cleaner.

They are now 33 years old and are overdue for a refresh. Found this company here in the UK who supply rebuild kits: https://mrinjectoruk.co.uk/ I send them an email before ordering and they advise BMW kit 10 was suitable for the 0 280 150 715 injectors. Arrived next day.

Rocker cover off for access, took the wiring harness off, loosed the 4 bolts holding the fuel rail on and pulled the injectors up and out. Had to remove the clips from the top of the injectors which hold them to fuel rail and I was able to get them out one at a time.

Condition as removed, pretty dirty. The o-rings are still in reasonable shape as they have been changed before.

The filters on the the other hand were dark and old looking. Getting the filters out took some careful manoeuvring with a screw driver and a pick.

While the cap, o-rings, spacer and filters were out dropped them into the ultrasonic cleaner

After all 6 injectors it was starting to look a bit disgusting

Shiny new parts!

Pushed in a the new filter and added a new o-ring:

Installed the new spacer, o-ring and cap on the other end.


Repeat 6 times for a full set!


Installation is reverse of removal, put all the injectors into the fuel rail first and add the retaining clips. Then carefully line up with the intake manifold and push into position. Reattach the fuel rail with the 4 bolts and reassemble the rocker cover and crank vent tube.


Took it for a good drive today, seems to run smoother and idle better, so I’d call the a success!

Engine Work

Oil Filter Housing Plug Replacement

The M20 engine leaks oil, this is one of the places it started leaking from recently. The housing which the oil filter connects to and the oil cooler pipes has a plug. This plug has an o-ring which has gone solid and started leaking. BMW Part number 11429059338 – comes with a new plug and o-ring.

Some shouting and swearing to get the retainer clip out – nothing to grab on to so screw driver in the divet on the left.

Quite a bit of oil comes out here when it’s unplugged.

This is the content under the plug, shown with new plug and o-ring.


Cleaned up the old parts to go back in.


Getting this thing back in was not the easiest job. Ended up using a clamp to force it into place and put the retaining clip in. Used screw driver in the cap to move it to the correct angle and location before removing the clamp.

This job took a suprisingly long time to do as it was quite fiddly.


Vacuum Leak Testing Smoke Machine

I watched this video from martinbuilt showing a DIY build, after seeing a pro grade unit being demoed used by the Car Wizard in his essential shop tools video. The cheapest commercial smoke machine I could find is about £180, so a DIY one is much more suitable for the few times I’m likely to need this like I did today.

This ones diy with a bit of design flare to it, only because of the fancy oil container I found on amazon.

I built this last year but this is the first time I’ve been able to use it to test a problem on a car.

Chopped the top off (it’s not very air tight unfortunately, but good enough).

Mock up using some foam a lid with two electrical connection and two tyre valves.

Cut out an aluminium blank to use for the new top.

Foam design revisions 2, move some things around and put in the original fill lid to make it easy to put the white mineral oil in.

Cut all the required holes into the blank.

Mounted all the hardware and added a wick and some resistance wire. These will generate the smoke, as the resistance wire heats at lot and the white mineral oil smokes when it’s heated.

Tested the resistance wire, pulls 5 amps at 12 volts.

Assembled, the lid is not a 100% seal but that does avoid an over pressure situation.

First smoke during testing!

Had a good chance to test this, we’ve got an E36 Compact with an M52B28 engine swap done many years ago. The engine has been idling high randomly, normal RPM with the MAF off. This suggested a vacuum leak, but the question was – where is the vacuum leak. Did try changing out the idle valve as we’d picked up spare on ebay but that didn’t help.

So we used this setup to test and find the leak. First pulled the airbox so there’s more room.

Hooked the plus and minus up to the car battery, ran a tyre inflator into the smoke machine. From there put a latex glove over the maf and poked a brass pipe into it. Theres a rubber pipe from there into the smoke machine.

As there was quite a bit of smoke coming out of the tin I added a load of tape to reduce that.

Started to see some smoke waft out from under the intake manifold. 

Took the pipe off the alternator for a better view.

It was clear then that the smoke was coming from the crank case pressure regulator valve. Time to order a new set of hoses and the regulator valve.

Some testing on video:

Engine Work

Coolant Expansion Tank

Purchased a new coolant expansion / header tank to replace the original 1988 part from the donor car. For the first time since building the car you can see the coolant level! Should have replaced this years ago, but it’s not the cheapest part to get new. The nice thing is you can still get new original ones. They were use on the E30 and on the Z3.

Added a new blank cap to replace the level sensor cap with a fresh o-ring as well.

Needed little bit of modification for the lower mount – a hole drill into it.

The old one is almost solid, the lower hose connection was coming to bits too, the metal insert on its way out the end.

Looks a lot nicer with the new tank.

You can really see the opacity difference.

Nice clear fill level:

Engine bay looks much cleaner now.