Welcome to our BMW E30 based Marlin Sportster Build Site,
we hope you will find this documentation interesting and helpful.
The site has grown massively since its inception in 2005, I hope to one day soon improve the navigation as it's a bit overwhelming to start with. The main areas of interest to builders will be:
The rolling chassis build
Bodywork Fitting
SVA Issues
Final Assembly
If you would like read about the build in date order then have a look at his page.
It took 2.5 years to build the car and pass SVA 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!)
Finally in March 2009 it was painted, a full set of images is here.
To read the whole build from the start click here.
03/08/2006
Spaced Out
The 30mm (per side) H&R spacers came from http://www.performancealloys.com/
They are very solid and not too heavy!
They are very solid and not too heavy!
02/08/2006
Tuning
Added a few more items that cropped up during the build so far to the tuning section
30/07/2006
It drives!
It drives! Replaced the clutch slave and master cylinder today and bolted on the old E30 exhaust. There was nothing stopping us from taking it for a quick spin! (Literally as I found out with the rather sharp clutch on the first run or two
)
Click me to download the video (6.1 Mb DivX 5)
)Click me to download the video (6.1 Mb DivX 5)
28/07/2006
Spot light mounting
Today the spot lights were mounted. Seemed like a simple task but took longer than expected. The first step was to grind the back edge of the brackets so that the mounts could be evenly spaced on the chassis. The following picture shows the before and after grinding. (left - before & right - after )
Click me
Next the holes were marked, drilled and tapped. When the bumpers are mounted the outer screws from the spot light brackets will go into the bumpers, this will hold them in place.
Below you can see a completed spot light bracket. The mounting holes were counter sunk so the screw heads do not stick up as high. The spot light mounting hole needed to be widened from 14mm to 16mm, this was done on a lathe.
The following pictures show the finished mounted bracket and spot light
This is how our Sportster looks with mounted spot lights and headlights. :)
Click me
Click me
Next the holes were marked, drilled and tapped. When the bumpers are mounted the outer screws from the spot light brackets will go into the bumpers, this will hold them in place.
Below you can see a completed spot light bracket. The mounting holes were counter sunk so the screw heads do not stick up as high. The spot light mounting hole needed to be widened from 14mm to 16mm, this was done on a lathe.
The following pictures show the finished mounted bracket and spot light
This is how our Sportster looks with mounted spot lights and headlights. :)
Click me
22/07/2006
Wiring Continued
Back to the wiring jungle :)
After the success of getting the engine running the rest of the wiring needs to be completed. The headlight wiring was first on the list. We have decided to use the light switch from our donor. The switch works very well and has a dimmer function for the dash & instruments lights that we want to incorporate into our Sportster.
For the light switch testing a front light was mounted on the car, this made the testing much easier as the results were instantly visible and no need to hold a multimeter up to each connection.
As with the rest of the wiring the first part was to study the BMW wiring diagrams. It became clear that the wiring diagrams did not match the wiring from our donor. So to start with the diagrams were put to one side and the wiring from donor was used as a guide to wire the light switch. The result was that lights did not function correctly, when the light switch was moved to position 1 the low beam came on, this should only be the parking light. Low beam should only come on at position 2.
With all of the confusion the multimeter came out and the switch was analysed, with the help of the wiring diagrams the switch was successfully wired. The light switch functions just like in the original car.
We will also wire up the spot lights to the high beam. Originally we planned to used the spot lights as front fog lights however in this part of the country front fog lights get very little use. With the spot lights on high beam will give us more light for driving in the dark (and help to blind rude drivers :) )
Light Off
Parking Light
Low Beam
High Beam & Flasher
Max showing us how headlights are supposed to work! :) click image for a larger version.
18/07/2006
Cars Back
Its been a bit of a saga, but the car is back in the garage. Sadly minus an exhaust. The were issues with both of the two companies involved; we don't want to go into details about this.
Needless to say but we now need a plan B. This won't involve side pipes and will be centered around high performance rather than the show factor.
On the cards is a BTB 6 branch manifold. The rest of the system at the moment we're not sure. We'll need stainless pipes and some form of muffler/silencer/back box arrangement. Some options out there such as Magnaflow, Jetex or maybe a standard E30 "cat back" system without a lot of bends (minus the cat, except Max that is, but he's more likely to sit in the car than take part in filtering exhaust gasses).
Important it to keep under the 101db SVA limit and the minimum radius rules of the tips.
Needless to say but we now need a plan B. This won't involve side pipes and will be centered around high performance rather than the show factor.
On the cards is a BTB 6 branch manifold. The rest of the system at the moment we're not sure. We'll need stainless pipes and some form of muffler/silencer/back box arrangement. Some options out there such as Magnaflow, Jetex or maybe a standard E30 "cat back" system without a lot of bends (minus the cat, except Max that is, but he's more likely to sit in the car than take part in filtering exhaust gasses).
Important it to keep under the 101db SVA limit and the minimum radius rules of the tips.
06/07/2006
Exhaust
Car is at the exhaust place now! Parts didn't come for the clutch, so wasn't able to take it for a drive - never mind, time for that later!
We'll be off on Monday to inspect the mock up. Will try and take some piccys :)
We'll be off on Monday to inspect the mock up. Will try and take some piccys :)
04/07/2006
Clutchy issues
Spent some more time playing with the car today. Readjusted the rockers again to double check everything - soooo important on the M20 it runs much smoother now. Still not gotten around to testing the AFM / ICV yet.
Also spent some time with the clutch. Took the pipe off the front of the master cylinder expecting it to still be solid and ended up with my trousers covered in the brake fluid in all the wrong places - doh!
Anyway moving on! Now the pedal moves again it was time to bleed the clutch again. The pedal now worked but the clutch didn't seem to be working. Unbolted the slave cylinder and the pin does not move at all when you press on the pedal. It sounds like there is an air leak in there. No mater I defiantly know what the problem is and the parts on on their way (along with some vacuum hoses and a water hose)
Also spent some time with the clutch. Took the pipe off the front of the master cylinder expecting it to still be solid and ended up with my trousers covered in the brake fluid in all the wrong places - doh!
Anyway moving on! Now the pedal moves again it was time to bleed the clutch again. The pedal now worked but the clutch didn't seem to be working. Unbolted the slave cylinder and the pin does not move at all when you press on the pedal. It sounds like there is an air leak in there. No mater I defiantly know what the problem is and the parts on on their way (along with some vacuum hoses and a water hose)
03/07/2006
An update and some pictures
Ordered new clutch master/slave cylinder as well as various vacuum hoses to replace old and possibly rotten ones causing the high idle on the engine. II might try to get my hands on a second hand AFM if the new hoses wont fix the high idle. Once its back from the exhaust place and has a few panels on we'll take it down to the local garage for an MOT.
As I've not posted any piccys in a while here's a few:
"Ghetto" exhaust & fuel tank
and "Fuel tank holdery-me-jig"
All fine for testing, gave it a good run again today after silicone sealing the brake master cylinder to the servo. It runs much nicer now.
Stock exhaust header and down pipes from the donor car. Its all leaking a bit at the moment, but no worries, new exhaust soon! :)
Fuel box holder, a temp solution while the car is off to the exhaust place this week.
As I've not posted any piccys in a while here's a few:
"Ghetto" exhaust & fuel tank
and "Fuel tank holdery-me-jig"
All fine for testing, gave it a good run again today after silicone sealing the brake master cylinder to the servo. It runs much nicer now.
Stock exhaust header and down pipes from the donor car. Its all leaking a bit at the moment, but no worries, new exhaust soon! :)
Fuel box holder, a temp solution while the car is off to the exhaust place this week.