Hello all… I have a ‘little’ bit of experience with both of these packages
Haven driven both, coached both, tested and tuned both. We, at ogp, have had extensive use and building of both motors. IMO, the fun factor goes to the rok. Slightly faster than the Honda, with more revs (roughly 13600 vs 12600…standard revs, no over rev) it sings instead of grunts. Not as easy to lug around, it makes up for it by having a bit more top end rush. Stay in the power band and it rewards you with a seemingly stronger pull through the top gears. It does however require one to be more on point with gear selection. The Honda allows a bit more freedom as it does have a little more initial pull. The dry clutch makes launching the rok easy.
The heavy wet clutch requires a bit more finesse to launch, under racing start conditions, on the Honda. Finding neutral is easier on the rok also. The shifting feels lighter as long as you aren’t over revving on the rok. Neither motor has a rev limiter! I just spent the last 4 days doing separate driving schools with new people to the shifter platform. Each one of them over revved the rok to well over 16000rpm, easy to do in miss shifts and false neutrals. Rubens was engine breaking in Orlando and consistently hit 15+…very hard on the reeds and the bottom end. I’ve had plenty of experience with the same in Hondas, engine breaking and excessive down shifting can rev the motor over 15. Actually seen one take out the bottom end, in Vegas, on a Honda. Which brings me to the next point…
The rok will require you to be a bit more on top of things. With a high rpm ceiling and an ‘iron’ bore your piston will need to be paid attention more. The Nicasil (spelling?) Cylinder on the Honda is almost bullet proof. Runs the same piston ‘always’ making the do it yourself guy happy. At a local level you can just slap in a piston/ring and a new head gasket and if you go. No ‘need’ to hone every time, or to size your piston (this is true to a point). Bottom ends are virtually bullet proof on the Honda. The roks is also very strong and very well built, but does require a bit more ‘looking over’. Clutch is stellar on both, but the dry clutch on the rok will also need to be looked at at a higher frequency and cleaned up…
Reeds, well that’s very dependent on how one drives, as does all of the previous comments. If you are a hack with the gear box, neither will hold up. Less so the rok, it is a ‘true’ race engine. If you lack the maintenance schedule, the time, the effort the Honda would be my choice. As a stock engine it was designed for motocross and being in the dirt. It will hold up better if your are not on top of things. The rok will run very well without proper maintenance, and hold up (2 race weekends, 4 newbie days learning to drive one, all on the same engine… 1 top reeds replaced, even with the over revving) the bottom end…? Idk I would have to ask Mario I wouldn’t advise it though lol…love your engines people!
Is likewise fairly easy on both. Once you have a good baseline, you can pretty much stick to it, as long as you run a ‘tad’ rich. Obviously driving styles and track locations will change things, but it is very easy to work with both. The rok, imo, wins the carb game. With a fixed range to run it makes the average tuner more on point. The fairly open carburation on the Honda requires you need someone to give you a good base.
If you are a once a month weekend warrior, or a do it yourself guy, the Honda wins. If you want a true race engine, bigger smiles and a way better sound, the rok wins hands down…I love my Hondas but the vortex is truly a piece that tugs at a racers heart strings…
Each has it place. The vortex isn’t going anywhere and growing. It is well supported in areas. Has an international series and a world final race (I’ve been multiple times). Imo, more fun to drive. The Honda is a work horse. Parts are cheaper. Requires less to keep running (just not at the front :)). A lazy man’s lugger if you will. Parts are getting a bit more difficult to find, depending on the vintage of your cylinder. Is it dying? Maybe. Will it go away? All things do come to an end… Just when!? Rebuilds on both depend on how they are used and at what level you are racing.
I’m sorry if I rambled, if you have any legit questions you can find me on Facebook or at ocala gran prix.