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LuckyTiger engine project

This is my current project that hopefully will deliver a different kind of XB feeling.

This project is only possible due to the support of my mate Tom and Lucky who is my engine builder. There are several other contributors that have supplied bits or still involved in the process of making them.

A lot of people I have spoken too feel that the long stroke XB engine is not far off its limit. So if you want to get more power to shape 2 secs of your lap time things get tricky. Just changing the ECM does not do the trick. Doing away with the standard airbox and just having an open air intake is a good start but does no result in a real power gain. Doing the work on the heads (stage 1) will certainly improve performance considerably, but it will not really make the bike faster. The only thing that happens it will go faster into the rev limiter. Playing arround with a TFI and the standard ECM is also pretty useless. The permanently self learning stock ECM is a real pain. To improve the engine by 20 BHP you need to dig deeper. Here comes the larger bore short stroke and the 7500 rev limiter of the XB 9 ECM into play. Combined with the XB12 primary ratio your 2 second goal can be reached. A reasonably working after markt exhaust is another problem. In the low price range only the HSA Power race seems to be a possible solution. But when you want to maximise the gain than you have from my of point view little other choice than to build an exhaust that works for your engine.

Here is an overview of what we are building:

- base is a 2003 XB 9 engine
- 1208 cc short stroke (stroke lenght like the XB 9)
- forged pistons (from JE Pistons)
- Stage 2 heads (specially made lighter and larger (47.5mm) intake valve and stock size lighter exhaust valve with 7 mm stems)
- Aluminium pushrods (from Andrews)
- changed cams (Revolution performance)
- lightweight hydro lifters (new development from Schubeck)
- Roller rockers (Revolution performance)
- Seriously reworked crank/flywheel/rods (balanced, 2.5 Kg less weight and reduced diameter etc.)
- custom oilpump drive gear from LuckyHands
- Buell race ignition rotor
- Adjustable air intake (one of my own developments, combined with a 9 series type glas fibre lid and a K&N air filter solution)
- Custom exhaust system with special flanges for the heads based on modified DeepThunder pipes
- Ultralight Carbon exhaust muffler (design by Tom and myself)
- lighter primary sprocket
- lightweight alternator from the XB RR including the RR primary cover
- lightweight primary drive (my own development with parts from the US and parts that I have developed and got made. Works absolutely fine since 8000 KM (09/2006) in my road bike. The version for the 1208 engine has a 1/3 lighter starter rim and has a modified clutch hub.
- Lightweight Aluminium clutch plates (Thorsten Durbahn)
- Lightweight secondary drive train parts (Free Spirits)
- Buell Factory (fully programmable) Race ECM
- transmission gears reworked by Hals Speed shop (USA)
- ceramic engine bearings from Woodcraft
- Custom carbon muffler that is build with a new type of experimental resign that can take up to 400 C heat long term! The muffler weighs less than 2500 gramm and that has a similar volume to the Buell Race Muffler. Designed by myself and my mate and Tom.
- custom made aluminium side stand
- Titanium bolts were possible and obtainable!
- the dyno tuning/set up of the ECM/engine will be done by Volker Schirmer from Buell Hannover


We have done loads of other small modifications on the engine (oilpump improved, plenty of titanium screws, etc) to make it even lighter and more durable and we will hopefully see how well it works together at the end of May.

The bike has now got about 20Kg less weight and the engine has arround 6 Kg less rotating masses. That should become a slighly more nimble bike than the original and looks almost original.

The engine is aimed to do close to 8000 RPM. The whole engine concept is aimed to result in an engine that revs up in a flash and due to its reduced masses/lightened valve and drive train feels like the next level of Buells development strategy. 120 bhp at the rear wheel would be nice and I am pretty sure that we achieve this. Please have a look at the German pages to see the pictures.

Why do I do this

I love riding the XB despite its distinct lack of power. A test ride on a XB12S was my return to biking after a break of arround 15 years. I immediately felt comfortable on the XB and I do like its character. But since this day I wanted to have more grunt. Anybody can be fast with an electronically moderated Japanese test tube "baby". Being fast with the XB gets the rider back to simplicity. Brakes/clutch/throttle. No interfering of almighty "systems control" ESP, ABS and what have you.

I gather it would be worth while mentioning that the biggest problem with getting more power from your stock XB is the ECM and ultimately this part has to go. For the moment I use the manifold of a 2006 Ulysses/modified air intake as mentioned and a reprogrammed 9 series Race ECM with the curves of a 12 series Race ECM and a few other adaptations (supported by Stefan Freitag who is another German chap who is quite knowledgeable regarding the XB electronics). My 12R road bike is fitted with such a modified ECM and there ist works very well. Lets see how long the "long stroke engine" can take the punishment (I regularly shift gears at 7200 RPM).

Status (07/2007) of the 1208 short stroke project:

The engine case has been put together ans we are currently finalising the engine rebuild (checking valve clearance and lifters/pushrod lenght etc.) I so far have invested almost two years of planning and I have managed to get support from a lot of people. The core team consists of a well known a German engine builder (Lucky) with many years of experience with building fast and reliable engines for the tube frame models, my mate Tom Pfeffer who is a genius with regards to precision manufacturing and Thorsten who has infected me with his madness. A major contribution comes from an American tuner (who makes the cylinders for the RR model).........well its Brian Nallin. We use his big bore cylinders.

There is loads more information and pics available in the German section.

By the way, the bike is my hobby that got a bit out of hand. I never intended to develop parts myself, but after being led down badly by some people I decided that I would not give up. Now one year later things have come along nicely. I normally work as a radiologist for the NHS in England and I very much enjoy this, but the bike is my true passion.







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