Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Maximum recommended engine speed

Is there any information on which we know the maximum speeds of the XWedge according to the mechanical parts assembled, yesterday I connected ProTune and discovered by chance that the engine arrived at 6707 rpm with the cut-off set at 6350 rpm, the problem would be that the ignition cut is only done on one cylinder I think it happened to me when accelerating in second or third gear or when I slammed the accelerator to go back to a lower gear, the engine running .650 valve springs, lightweight 618 camshaft rocker arms.

From the official X wedge Manual:

Exceeding 5,800 RPM under any circumstances may damage the engine!

My Protune 2 set up has a soft cut at 5700 rpm (one cylinder) and a hard cut at 5800 rpm (both). I think that is the normal settings for the preset maps as well. I think that in reality there is a bit of a safe cushion built into in the 5800 rpm limit but not a lot as the loads increase dramatically with increased revs and it's hardly a smooth, vibration free engine. Is it still running well with the 6707 rpm buzz GLLOQ? It maybe has lightweight roller rockers but it still has the massive heavy weight crank...... There must be a way of making the X-Wedge rev some more as I remember seeing them on drag bikes in the USA in 2008 and they were doing more than 5800rpm at a guess.

It still works like a Swiss clock I have just done another 80 km this afternoon, the VDO rev counter cannot be as fast as the revs of the engine on the first three gears and in fifth gear I arrive very quickly at 6350 rpm on the highway.
I very frequently drive at less than 2000 rpm in fourth gear without having a bad engine operation the low engine speeds are very smooth compared to the original 121 cub engine, the thing that has also increased is the engine vibration cause may be the 4-3/8" crankshaft.

Very true...I find that changing up from second at 5000 rpm only just avoids hitting the 6800 rev limiter when having fun.
The needle on the rev counter is very heavily damped so takes a while to catch up with the engine on proper acceleration.

I hope that was a typo Calum, 5800 rpm rev limiter? I find there isn't a lot to be gained by exceeding about 4500 rpm before changing up, it's not keen on higher revs. It drives much like a turbo diesel to my mind, fairly narrow power band but goes like a train when it's in there and runs out of power all of a sudden as the revs climb.

Indeed it was...typing was never my strong point! Definitely 5800 limit

As an aside, what a difference from the Pembleton! Changes at 5000-5500 are the sweet spot with the MG 850, although with a bit of tuning we are largely free of the low-end lugging that one has to be careful to avoid with the S&S.

Agreed, the Moto Guzzi 90° V twin (big or small block) is a totally different animal from the narrow angle S & S. Much smoother both at top and bottom end of rev range.

just to add in a momentary peak above the limit is probably not a big deal (I say probably, because the XC-wedge nothing is predictable, considering $&$ is not supporting it)