Well I have driven these engines so I know from experience with them. Yes the F11 will have more top end than the X11. The F11 also has a ton more bottom end than the WS9 or the X11. If all you want is killer top end RPM's then yes the F11 will be a close match to the WS9 in terms of top speed only. The F11 is not even going to be close to the smooth bottom end that you have with a WS9 tho and I know this from running the engines. The F11 or the Rally11 (same engine, different head) are very abrupt engines that feel much like an on off switch with instant power. Great power for a truggy but I found it very hard to drive in a buggy.

Just because an engine is a 3 port does not mean it will have less top speed versus a 7 port engine. Have you ever seen an OS Speed on the straight?? I also have a Shark9 with a Ceramic bearing in it.. the Shark9 is a X11 with a balanced crank and I added the ceramic bearing... That 3 port engine had more top end than any of my WS7's, WS7II's or WS9's ever had.


Have you ever tried running an Onroad crank in an offroad engine?? I see you say they are for top end? I ask because I have used onroad cranks in my offroad engines as recently as last year... I did this to get extra snap out of the engine for running it in truggy. Back to back tests proved that the onroad crank made more power from 1/8 throttle to full throttle.