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.

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.

Chassis

Radiator Return Pipe

Since the car was built the return radiator hose as been a long flexi pipe, this was never a good solution. At some points the pipe rubs which eventually would have cause a leak.

To solve this the flexi pipe has been replaced with a 90 degree aluminium bend and very short run of flexi pipe on either side.

Aluminium bend installed in the car

 

New pipe from below (missing the hose clamps in this photo!)

Filled and bled the coolant system, checked for leaks.

No functional difference, but safer long term.

Engine Work

Varex Exhaust Video

Had a chance to record some new footage of the exhaust. XForce Varex VMK51-250 variable volume exhaust – it’s pretty much straight through when it is open. Here’s a few runs with the back boxes set to closed and open for comparison. The engine is a BMW M20B25 with a crank from an M52B28 making it an M20B28. It has a dbilas 282°/272° camshaft. It’s running the original 80’s motronic from Bosch with a chip map design for the stroker conversion. It does pop a bit when the exhaust is warm and you change down. Would benefit from a more modern ECU and tuning (someday!)

Engine Work

Water leek, from back of the head

Another week, another new fluid all over the floor! Coolant this time from the rear port on the cylinder head. That’s the pipe that goes to the interior heater core:

Took it off and cleaned everything up on the head

New coolant flange gasket fresh from eBay!

Eveything fitted back together (after dropping the bolts…). It’s a little bit fiddly getting this back on with the battery tray in the way. The bolt seen in the follow photo on the left of the image is much higher up than you’d think.

The nice thing about the Sporters, more room to get behind the engine is just 4 bolts away!

Engine Work

Fuel pipe refresh, car pee’d all over the floor!

Car pee’d on the floor…

It’s a bit drippy here at the back, but also at the front on to the start motor – not overly safe and smelled pretty strongly of fuel.

The main leak is here at the back between the hardline and the hose. The hoses have gone quite hard with age. There is a flare on the copper pipe.

All the fuel hose is 12-14 years old, this was visually the worst – the main picked pipe which is most exposed to the elements. The rest hard gone hard but were not cracked yet.

Emptied 25ltrs of fuel out the car using the Power Probe – all power disconnected on the car, hooked the probe up to the battery and switched 12v on the the positive side of the pump. Drained the tank very quickly into fuel cans.

Brand new hose up front for both the feed and return. Although these pipes all looked OK it was worth changing everything while the fuel system was drained.

New pipe from the tank to the first filter, to the pump, the next filter and then down the copper pipe where it was leaking. Also replaced the return rubber line.

Here are the rest of the old pipes that when in the bin, these had gone pretty stiff especially when compared to the new pipes.

All back together again! Used the power probe to prime the whole fuel system and check for leaks before starting the engine – fired up instantly, no waiting for the fuel pressure to build up when you prime the systems.

If you’re going to do any work on rubber hose, this tool from Sealey is invaluable, cuts nice straight ends every time!

Engine Work

Coolant flush and refresh

This drain plug has been leaking forever, the drain part is reverse thread and normal thread into the radiator. The thread into the radiator needed more PTFE.

Due to topping up with water over the last couple years the coolant was starting to get hotter than normal when the engine was pushed. With the new coolant G48 with suitable BMW specification the needle stays steady on 80ºC when pushed hard. When testing on idle at a standstill the fan kits in at 88ºC and comes down again nicely to the low 80’s. 

Chassis

Varex exhaust build part 3

Built the other side of the exhaust today. Welding is ‘better’ than when I started but still pretty uneven. I can’t weld too far consistently around the curve yet. Did punch a few holes in the metal in places which results in having to ‘glob’ in filler rod to build it back up again. This part was back gassed as on the others before as it was a butt joint.

The 45º and straight pieces are sleeve fit, have welded these too so less clamps are needed. It also cuts down on potential exhaust leaks.

Once the two back boxes were hung I used some boxes and various peices of wood to hold the tips in place at the right height, this is with the car on the ground. Nothing on the Sportster is straight so this was done visually.

I used a piece of angle metal to line the tops and ends of the tips up. This helped make sure the tips were aligned  straight with the ground, with each other and spaced from the back of the car.

Welding the tips on was a bit tricky, blew a few holes in the metal especially where the gaps were bigger. The left box alignment is slighly off, but it’s not visible once mounted and the tips are in the right place visually.

Both exhaust pipes mounted, the v-bands are visible in this shot. I used a tiny bit of exhaust paste on the mating surface, shouldn’t be needed with v-bands but I’d rather not have to take them off again! Also visible the zip tie exhaust hanger, nothing like attaching your exhaust to your suspension ;o)  Kinds tempted to make some straight pipes that can be put in place of the back boxes, but that’s a whole new level of noise (did try running it with just the header and you need to wear ear protection…)

The more permanent hanger, this is a part is from pypes a US manfuacturer of exahust pipes. Had that left over from building an exhaust for the Mustang (http://www.mustang67.co.uk/exhaust-upgrade/) last year. Available at https://www.summitracing.com/

View from the otherside, wiring is hanging down. These cables need plumbing in properly and the metal shields putting back on the mufflers.

Car down on the ground from a low angle, the exahust tips are closer together than before (due to the input on the backbox being offset rather than in the middle).

The tips stick out a little further than the old ones, the wall thickness and slash cut work quite nicely.

Temporarily wired up the control box, and now for the noise test:

Closed it’s quieter than the jetex micro bullet muffers + the magnaflow boxes. Open it’s a bit of a beast, louder than before so that should be fun 😉 It’s pretty much were I wanted it to be, will see what it’s like on the road once the wiring is done.