ROK Shifter engine Road race gearing and jetting

Going to race a Tony kart with a ROK shifter engine at Daytona, can anyone give recommendations for gears and jets?

19/20 if you find youre running in a draft, 18/20 if you aren’t. Start with a 165 main if using the rok shifter airbox and lean it out if needed (better to be safe than sorry)

Awesome, thank you! Also, engine was built by a sprint track company, would I have to worry about the timing or anything?

It will work on the sprint setup but you won’t get any of that top end rev that you need at Daytona especially since the pipe isn’t helping you. May be worth trying to raise the port height and adjust the timing for Daytona. I dont know the specific values.

following this, as ive been interestted in getting into road racing with my rok shifter.

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Hey Jake I think you have me on FB, feel free to ping any questions. I ran my old rok shifter at summit point and mid Ohio. Stock configuration works but the pipe doesn’t really like the sustained rpm so you dont get any overrev like you would on a honda or kz. Mid Ohio specifically best you can do with the rok shifter is 2sec off pace. For summit point with the long straight you’ll most likely just be racing against the Hondas because its pretty fairly matched at that track, I imagine it’ll be the same for Daytona too.

How does it do with a KZ pipe on there? Assuming the engine is being run in a regular shifter class vs a RoK specific one.

You can run a stock rok shifter with an airbox and an RTZ pipe and gain most of the horsepower back but you’ll still be down compared to full kz

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The entire RTZ top end can just be bolted on to a rok shifter bottom end since the rok shifter bottom end is just the RVXX so it can handle the kz power. I had my rok shifter built in to a kz for Daytona last year but complications arose (unrelated to karting) and I wasn’t able to run it there. Then a good deal on a kk1 came up and I sold my rok stuff for that since im light and can use the weight break the kk1 offers.

Here is a video of the rok shifter with RTZ cylinder, head and pipe on a sprint track. It was spec’d for Daytona so mid-range power is non-existent.

Link to YouTube video

I do! And we’ve talked on there before. I bought an airbox off you to run with my rok shifter actually.

Heres where that airbox is now lol

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Yeah I race in the NW with an actual RVXX cylinder and pipe on my Rok shifter bottom end. Ever since we switched to a TM flat top piston and lifted the cylinder a tad I’ve had no issues running with R1’s on sprint tracks. Haven’t faced an R2 yet. I did crack the TM piston and seize it once it burned a hole, but it was on about 6hrs or so if I recall.