hi again, just in a posting mood, so here we go. Back in the UK i have a British supersport spec motor for an 05 zx6rr N1. This comprises of fully worked head, kit cams, matched pistons, blueprinted, matched rods, kit shell bearings, head gasket, genny, plus the kit ecu, loom etc. When i bought the bike the 'kit motor' was out of the chassis and on the bench, i checked the cams, porting etc and was satisfied that the seller was selling a genuine engine, since then i have also checked the part numbers of the cams etc, and it all tallys up to being a decent engine. The only thing is the damn thing does'nt make any power, less than a standard motor, we had 106bhp at the tyre, this thing is supposed to make in the region of 125-130 at the tyre. The things i checked are; cam timing, compression, and also tried to re-map it with a different ecu box (ignitech), fully mapable, we had to do this as we did'nt have the kit interface box for the kit ecu.All this to no avail, so ive ended up putting the standard motor back in. The 'kit' motor, when ran, sounds quiet, revs quick, no smoke, etc, it sounds like a sewing machine.........just no power, anyways, since then i have stripped and rebuilt the head and will be inspecting the bottom end, but im sure ill find everything is ok, even if it was a bit worn, it should still make more power than a standard motor, the cylinder head porting is a work of art. Any thoughts on this would be appreciated. thanks Anthony
You can port heads and cause them to make less power. What were the compression numbers and is that hot or cold?
I can't remember off hand, but they were well within the usuable range, this was one of my first port of calls. The dyno would have showed any fueling issues, ie too rich or lean, that was pretty much spot on, and not too far out to lose so much power, we did a compression check with the motor cold and out of the chassis..................did'nt think about doing it hot............................anyways that motor is half way through a rebuild, im back in the uk at the mo and am starting the bottom end inspection this week, i have already rebuild the cylinder head, which was'nt too bad, ie coked up, the valves were all looking good too. Im going to overhaul the whole thing. Maybe coming from a big Uk race team they ran it on race fuel? but surely that would lose me 20hp?
hi, no the clutch slip is only related to the standard motor im running in the bike, the tuned motor did'nt slip, just was down on power.....................thanks for the reply
hi, i was using the standard pump fuel here in the uk, 103 octane, so should have given a good figure with that
What were the cam timing numbers? Is it down on power throughout the rev range or just on top? Surface gap plugs? (R0045Q-10)
hi, it was a while back but i think it was down on power through the top of the rev range, now sure of the cam timing numbers........soz am using ngk surface discharge plugs, due to the high compression and piston to head clearance.
