Products and Services
Sskrunkwerks specialises in bespoke modifications to BMW ‘airhead’ motorcycles and has the skinny on how to make them go fast – whether for the street or full blown racing.
Dual plugging is an effective way of overcoming the inherent inefficiencies of the airhead hemispherical combustion chamber: The two flame fronts from two spark plugs ensure that the combustion process is more complete and provides smoother running, easier starting and improved fuel economy when carburettor jetting is tuned to suit. Dual plugging is highly recommended when increasing compression ratio in order to prevent detonation particularly when high octane fuels are not available
For street use, you can use the same size plugs as the top with a spacers for the lower plugs. For racing, we recommend using M12 plugs for the lowers (No spacers).
To take full advantage of dual plugging, the spark ignition curve must be altered. There are several options depending on how much work you’d like to do yourself. This ranges from modifying the stock bean can for post 1981 bikes to replacing the entire ignition system with one of the aftermarket electronic systems. Of course, in all cases you’ll need to replace the stock ignition coils with dual post units and install a couple extra spark plug leads.
email to discuss options
Pperformance street cam
Skrunkwerks has developed a dual pattern performance cam grind that provides up to 10-15% more power (depending on a particular engine’s configuration) while retaining the tractable torque curve that airhead riders enjoy.
The stock exhaust valves and ports are overly large which can result in overscavenging of mixture during the increased overlap period of performance cams as well as possible exhaust reversion. The Skunkwerks dual pattern street grind addresses this problem by reducing the size of the exhaust lobe in relation to the inlet lobe of the cam.
R75 and R90 riders:
There are few performance cam options out there for your bikes – send us your cam and we’ll regrind it with the Skrunkwerks Performance Street profile.
Post us your stock 308 cam for a re-grind: A$350 + delivery
(you can send your cam with timing chain sprocket attached. The reground cam will be returned in the same state)
To fully capitalise on this cam grind, a compression ratio increase to at least 9.5 is highly recommended.
email to discuss & order
Eengine rebuilds and performance upgrades
Whether for the street or track, Skrunkwerks have ways of making your airhead torque! In addition to providing engine repair and rebuild services, we can extract more beans from your beemer. A well tuned stock R100 in good condition will typically produce around 52-54hp at the wheel. Depending on your budget, we can help your bike generate up to 70 street friendly rwhp or up to 90 for a full blown racing machine – that’s around 100hp at the crank.
Street friendly performance upgrades (up to 70hp at the wheel):
- Cam: Dual pattern performance street grind.
- Compression ratio increase to 9.5 – 10
- Dual plugging
- Mild porting job.
- Dyno tuning of carburettor.
- Carburettor upgrades (Dellorto or Mikuni)
- Exhaust upgrades.
Racing performance upgrades (up to 90hp at the wheel)
- Cam: High lift (12.2mm at the valve) racing cam.
- High compression pistons and further compression ratio increases up to 11.5:1
- Inlet valve increases up to 46mm
- Full blown 190-200 cfm porting job on flow bench.
- Piston, conrod and crank balancing.
- Tuned exhaust system.
- Dyno tuning.
- Oil pump and clutch upgrades.
- Ignition upgrades
email to discuss options
Billet machined from 6061-T6 alloy, these clip-ons hold the bars at an angle of 7 degrees to the forks. The bars are from polished 304 grade stainless steel. All fasteners are stainless steel. For 36 and 38.5mm forks
AU$225.00 (Ex GST) + postage email to order
Aside from looking a treat. these clamps will stiffen up the front end of your bike, improving suspension and overall handling. They are machined from a solid billet of 6061-T6 aluminium and go very nicely with the CB clip-ons. Or you can bolt on the original bars.
We currently have triples for R100’s with 36mm forks and monoshocks with 38.5mm forks.
AU$188.00 (Ex GST) + postage email to order
Done away with that ugly filter box and left with an even uglier gap? Fill it in with our Filter Filler. Made from carbon fibre and top coated in WO Finish*, this fetching cover has good room to house a crankcase breather tank and filter. Fits all airheads from /5 onwards.
AU$215.00 (Ex GST) + Postage email to order
* WO Finish is a clear high gloss 2 pack polyurethane with a special translucent black tint which subdues that sometimes garish carbon fiber look under a rich, thick luster giving a slight 3D effect.