Karl, what do you have as measured advantages to the detroked engine? I know you and martinH(i think) have commented on the revability but have you ever managed to get some sort of comparable data. I know the theory of rod angles and piston speeds/burn times, wear and pressure on the bore etc but in pure performance terms could/can you measure the difference or is it just the above?

Eg I had a lightened flywheel once, car felt like it reved nuts but obviously if you put it on the dyno the numbers would be the same as a normal flywheel recording "braked horsepower". Again it effected the drivability as the lightened flywheel was awful to pull away with.

Obviously you have stated your choice. If you had a normal yb 2 litre you would have more bottom end, just wondering what happens further up the range. Eg on boost instead of compressing charge with the cylinder volume you are doing it with the turbo to get the sameish power - what promotes det or is less efficient? turbo Vs cylinder volume. I guess you can increase you intercooling to effect this too, your running the massive cooler and charge cooler setup adding weight and complexity to your build.

hmmm all interesting, MartinH has now gone another way with more volume and "good" rod ratio but does not "seem" to need as much intercooling.

Just airing things going through my head, dont know if there is a solid question there apart from measuring the differences of setups lol