67 replies to this topic

[TimS]

and your gona get £6000 from....

[Bluemini]

You can buy my 850 for £6000 if you want!!

Dunno if its normal or not, but it sounds like its air cooled at the moment. Its all noise and no action!

[Iain Tyrrell]

In Dave dave vizards old book he mentioned something about boring the 1100 to 1220cc and using a 1300 head....... Now where did I put that book ? You could be on to something interesting here!

[Al*]

I'm building a quick 998.... the one goin in rusty will already leave 1275's standing still and I haven't even got my hands dirty yet! :cheese:

Al

[YoungUn]

Al* How have you got a 998 without doin anything to it, to go faster than 1275

[TimS]

theres a difference between getting your hands dirty and not doing anything to it. I believe he means without an engine build

[bristolminimad]

i've got a 998 i bought from a club member after a destroyed mine on riv run, it's a flyer! but this could be cus it's on it's last legs!!! that was 54bhp when it was set up 3 weeks ago!!!

[Pavel]

Rich maybe torque figures should be more important for you...
All following suggestions assume no over-bore/stroking. Add those if you wish for an extra few figures
If you're going for torque, i'd do the following:
Majorly flowed head (not 1275 probably), with larger than standard valves, but no need to go over the top.
Compression raised to 12:1 or 11.7:1
1.3 Roller rockers (Others tend to favour high-end hp... no use in a stroker)
Lightened, balanced crank assembly.
Lightened flywheel (no increase in BHP figures, but very good!)
Twin 1.5" su carbs with a worked inlet
Cooper freeflow exhaust manifold, 1.75" bore exhaust system
I'd be tempted to install some straight cut drops in the box to minimize losses.
Despite this being a very controversial subject, I'd probably risk trying a scatter cam. These can give extreme torque figures in some applications (I THINK siggy's clubman made around 150 foot pounds of torque, uses a scatter cam).

I think the above is a much more 1100-like approach. It improves on what the engine does good (torque), and doesn't try to make a 10k rpm monster out of it. However, if its absolute hp figures you want, then:

Flowed and modded 1275 head
Flat top pistons, 11:1 compression
Crank wedged, lightened, balanced, toughened
Lighten, balance conrods
Lighten flywheel
Weber DCOE carb
LCB exhaust
1.5 roller rockers
286 kent cam

Pretty sure the 2nd option will be a lot less exciting to drive, but for looks of figures, its better and will probably reach 100bhp if assembled and run in well.