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.
30/10/2007
Interior
19/10/2007
SVA Pass!
It passed SVA today, thanks again to Mark top bloke!
(couldn't get a pic of us with car due to government regulations, never mind!)
16/10/2007
Last few tweeks before SVA retest
13/10/2007
Nearly there (and oooopsy!)
Lets get the mundane stuff out the way first:
Edge trim now firmly attached to the bonnet and surround
Holes in the tub for the belts to clear
Edge radius on the fibreglass
More stronger clips added to the brake pipes. Zip ties replaced with P clips
Ok I'm officially an idiot. After spending many ours buggering about with a camber/caster gauge make lots of adjustments and getting nowhere. Also measured up my Coupe as a reference. The front wheels have always looked a bit off to me. Turns out I was right. The wish bones are correct left and right, but they 180 degrees up the wrong was. DOH!!! Flipped the wishbone over, now the car auto centres no problem at all!
Note to all builders - make sure the more curvy part of the wish bone is at the front as in these pictures!
07/10/2007
More SVA fixes
Bracket made and installed for the brake compensator valve. Its now solidly bolted in place with a P clip. Also add an extra P clip to one of the brake lines.
Heat shielding installed for the brake servo and master cylinder
Rubber added to bonnet edges...
.... but ran out of rubber, doh!
Started on chopping the tub so the harness does not rub on the fibreglass
Started installing convex glass in the mirrors.
06/10/2007
Steel Bar
Here's a piccy of us at SVA:
A trip to Metal Supermarket in Southampton in the morning to get some steel tube, then a visit from TA member Black-Cat (Tom) in the afternoon. Huge thanks to Tom for bringing his TIG round to weld this bar in for us. He also brough his tube notcher which is an awesome bit of kit!
Tube notcher makes quick work of getting the angles and surfaces right for welding.
Tom welding the underside of the bar - not an easy place to fit in!
The resulting welds!
Bar ready for paint
And paint on the bar
05/10/2007
SVA Fail
It failed. However it's not that bad:
1) Seat back strength. As the seats have harness holes in an impact all of the force gets taken up by the back mounts and the seat back. I didn't have evidence that the seat conformed to the M1 Directive 76/115/EEC. I spoke to Cobra after the test and they that they've never had an issue with Roadster 7's and SVA, but the also don't have any documentation to send me, they will call me back on Monday and see if the can sort something out.
Two solutions, get the paper work or weld in a bar higher than the harness holes between either side of the roll bar.
2) Mirrors. Due to the seat backs getting in the way (more than 10%) of the rear view the passenger side mirror becomes a requirement. You couldn't see enough in that mirror. It requires convex glass. (and not just double sided taped on)
Two solutions, find some glass that goes in the existing mirror or replace the mirror.
3) Sheet metal edges on bonnet all round need rubber on them. Would have done this there an then but I need to go back anyway so no point in rushing it.
4) Glass fibre edge under bonnet requires a radius of 1.5mm. Ditto above
5) Steering geometry - car didn't self centre from full lock my fault for checking the properly. Need to get Camber, caster and toe in setting from Mark or Simon (not that I was able to get a conclusive answer before)
6) Heat shield brake master cylinder and servo - I put an ali sheet on there but consensus was that it would soak up more heat. Fix cover in heat shield, not problem got a box of that in the garage.
7) Brake valve compensator - I used zip ties to hole this up, needs a proper bracket.
8) Design weights were wrong on the form. Car is heaver at the back that expected - probably due to the exhaust. So need a letter from Marlin with new weights. The rear needed to be at least 563 (and the gross put up to cover this)
The collapsible of the steering column was a very close issue but they did pass it in the end after a lunch time chat with everyone else there and a study of the manual.
That was it so all in all not too bad, nothing that can't be fixed. Thanks to Mark the tester at Southampton was nice a guy and very honest about everything all these issue are very fair points and I feel better about driving the car with them sorted!
Interior projections all passed, exterior projections all passed (had to sand down the rear reflectors a bit more, but that was it!)
Emission were still OK, exhaust was so close you wouldn't believe. One pipe was 98.9 and the other was 100.7 with an average of 99.8db!
03/10/2007
MOT Video
02/10/2007
MOT Pass!
woohoo MOT pass. Did fail on 3 loose bolts first time through not bad!
Emissions were:
CO 0.97%
HC 151ppm
yeahy! 
took video on the way over will process and post some time later!
We got the speedo calculation wrong, thought it was not working but the millage actually went up on the drive. Luckly you don't need that for MOT.
All set for SVA Friday now

Oh and before I forget it stopped raining just before we left!






























