Triumphrat

tcb · 10-12-2006

I am interested in any info from someone who has had the 988 stroker installed in their Triumph. Balance issues, case machining required(if any), welded or non-welded crank, Carillo H or A rods, and fees incurred for these services.

sweatmachine · 10-12-2006

I think you will find no one has done it...

but let us know if you do!

tcb · 10-12-2006

I only use my bike now for track days and racing, so it gets limited mileage put on it, but pretty severe use. I intend to put in the Carillos regardless, so I have to tear the engine all the way down anyway, so I thought the extra 84cc capacity increase over stock would be nice considering that the bike is slower than just about everything else on the track. I originally planned on doing British Customs 989 kit but the huge overbore seems to look like it gets pretty close to the cam tower and I fear stress problems, where the stroker just uses the 904 (92mm) bore. The Thruxtons main track advantage is the torquey drive out of the turns, so a stroker may just be the way to go, rather than relying on high revs to generate the extra power. Input?

Mecchanica · 10-12-2006

I agree with your analysis. Torque in the midrange and over a wider range can be a bigger asset than a whole lot of hp at the top end.
The longer stroke and shorter rods alter the rod length to stroke ratio, and that moves the max. torque point lower on the rpm band and if you cam it properly, you will have a broader torque curve, too. Plus the extra grunt from sheer displacement.