Has Tesco 99RON killed my bike?

[BillyC]

Originally Posted by Wootan

Hi Billy,

Thanks for the info, although i'm interested to know how you've come to the conclusion that my engine has a new head, and doesn't run on a high enough compression to run higher octane fuel, without knowing what is!

Paul

It was a hypothesis, rather than a conclusion

In all seriousness, I think I've already explained the effects of running a fuel that is too high an octane for your engine can have. If you guys have trouble with the highest octane fuels... and it's not a problem with your heads and valve seals, then perhaps it's a problem with your compression and ignition quality.

Originally Posted by BillyC

Your S2000 has a very advanced engine. It is able to adjust when the mixture is ignited, how much is injected into the cylinder, what mixture is injected, and adjust the valve timing, and the amount they are lifted.

In essence your engine can change its compression ratio.

I hope you won't mind me adding this, but your engine CAN'T change it's compression ratio - in essence or otherwise. That's mathematically fixed: it's the ratio of the volume over the piston at Bottom Dead Centre to the volume over the piston at Top Dead Centre. (There are variable cr engines used for research only, and little diesel engines for models sometimes have adjustable cr, but no production bikes or cars have this feature as yet).

What VVT DOES do (as you correctly said), is alter the fuel charge that's taken on. Within certain limits, the bigger the charge, the more energy is released, but it gets the same squeeze however much that charge is.

I've replaced the spark plugs and no difference; it just won't start. The starting motor's turning strongly, but I'm sure I'll soon wear the battery out.

The air filter's fine.

My last hope is to check that each of the plug leads are firing properly. Then I'll just get it dropped at a garage for a carb overhaul. I can't think of anything else.

Anyone have any other ideas?

[glade]

Evo magazine did a pretty exhaustive fuel test a few issues ago annoyingly its the only one i can't find! a range of cars BWM m5, TVRs and Golf GTI etc rolling road graphs for every car and fuel.

What fuel are the SV's supposed to run on, because if it isnt mapped for 98RON and hasnt got the ability to advance the ignition accordingly (which i doubt the engine has) then in theory its a waste of time sticking better fuel in apart form the cleaning benefits. (which seem to cause other problems anyway)

And therefore is it better to stick in 95ron and use a bit of injector cleaner every now and then?

EDIT: golf is a swear word... well **** me!