Its a very touchy thing this feul subject, no harm done.

I'm heading to Arizona in Febuary for some kind of big nitro race. Jim from Fuzion x Motorsports will be there, I'm hoping to learn how to better tune motors from him.

I actually run the Sidewinder Purple Strike Team fuel. That is what I have 50% of. The application I read you were running the engine in sounded much more like an extreme on-road situation. If your running at very high sustained RPM's like that your going to need to have your tune PERFECT and yes the extra castor will help you. As for the Nitro... well many onroad guys run the lowest possible Nitro so they can make runtime during a qual. otherwise they run out of fuel trying to run 30%. Also if you are running constant high RPM's you should look into changing your rod every couple of gallons. I know a lot of the on-road guys talk about adding castor to a lot of the newer fuels because they are just too low in castor for their liking at sustained high RPM's. You might get some good advice in the Nitro On-Road Engine section about this stuff as well.

But in General more nitro is going to cool the engine more. Higher Oil content will increase the heat. Your drop in temps was more than just the nitro reduction. Changing fuel changes your tune in many ways as they don't all use the same oils in the same percentages.

So is the shim rule put 1 0.1mm shim for every 5% increase in nitro over 25%? Also, after some more digging I discovered that the piston/sleeve/con rod in the Shark 10 is the same as the Buggy 11 engine, but I don't see it available for sale anywhere.......any thoughts?

Honestly you should be just fine to run 30% with the stock engine shimming. You can add the .1mm shim to help the breakin process go a bit easier but there will be no problem pulling it out after breakin is complete. If your going to run more than 30% then you should start adding shims.

As for the P/S/R I am not sure where you can get that set. I would think A-Main should have them available soon if they are out right now. Many of RB's engines use the same piston sleeve and rod.

Thanks for the reply Chris. I will likely keep it stock for now...I'm assuming the Buggy11 is a relatively new engine, so maybe spare parts aren't available yet? I'll keep my eyes peeled

Can someone confirm bearing size of the Shark 10?

Front: 7 x 19 x 6
Rear: 14 x 25.8 x ???6?

I would like to grab a set of ceramics for down the road...

Thanks fellas!!

Anyone??

Hey man sorry I was racin yesterday. You are correct on the size of bearings that you need.

Thanks Chris!!....kinda what I thought, just making sure!!

Chris what do you recommend for a buggy engine from the RB Line-up? Usually medium size tracks. No blue groove where I live.

Don't know what is coming down the pipe.

Pipe and Header as well please.

Thanks

For a medium size track and not grooved up I would run the X11 with the 2045 pipe and short 198 header. If you can only get the engine with the new 2087 pipe combo that will work as well. If you already have a 2058 pipe sitting around give that a try as well!!

If you were choosing a all around engine what would you pick and pipe.header. Traveling would require a engine that can do it all.

Thinking B11?

Anybody know where a p/s/r for C6/B9/B10 is in stock?

Yo ham. I checked all my stuff last night and I don't have a P/S/R set anymore. I will call Jim today and see if they have any in stock there.

The B11 is a lot of engine. Yes it's fast and performs well all around. Unless you have a track with a really long straight I don't think you will notice a big difference. The B11 is going to make more power but that can also get you in more trouble at times too. The X11 feels a lot like the Shark9 with is one of my favorite engines ever!!! Drop a ceramic bearing in the X11 and it screams and gets great economy, but still not quite the power of the B11. So if it's the power your after the B11 would be it.