So you had her a buzzin eh !!!

any idea of the RPM you were turning ? I am not familiar with the car at all

I'm sorry to hear about your engine coming apart, but I am glad to
hear about how it met it's demise. I to, push my nitro engines to
their limits on a huge dirt oval track. I've learned to fatten to hi-
speed needle up some to keep them from coming apart. Pulling the
back plates off of the engines to check the con rod bushing, after
each of what we call "Rod Stretchin Action" runs, is a must. Like I tell my
engine modder, "hey, if she comes apart she comes apart. I know
I was pushing it way to hard in the first place".

I always get a laugh when one of the, blip-blipity-blip, off-road guys
post that his engine threw a con rod at or near the two gallon mark.
After all, he stated that he had done the proper six tank break-in,
hammered the engine at the track the next day and never heard of
pulling the back plate to check the con rod bushing after evrey gallon
of fuel has been ran through it.

Hell, I thought if you hold it WOT, that's how you get a long stroke!

I have to admit it was fun while it lasted, but seeing that I am not sponsored and I pay for my engines, I am in no mood of popping a engine at every race.

Ahh!, I just know that you won't quit. Add one or two teeth to your
gearing and go for it, again. I've thought about converting a 966 into
a GT car, but my buddys said my DM1'S were fast enough. Instead,
I'll be getting a belted GT car out of Europe next. As far as off-road goes,
I guess I'll be running Serpents next year. So, you know that there
will be one getting a dirt oval conversion on the workbench soon.
I may have to slap a two-speed on it and run some asphalt too.
By the way where is that big asphalt oval located ?

The track is at Sanair speedway in St-pie Quebec. Its a full size car track and they used to do pro karting. Since karting stopped going ther they turned them to RC on road. They have 1/8 and 1/5 racing there. They actually have three tracks all huge. One is a oval, the second is more of a kidney shaped oval and the third is a road course track. Plus they have a couple of aff road tracks for good measure.

I've tried searching....what is a good rule of thumb for engine head shimming? The manual states that if you run more than 25% NM to shim 0.1mm, but I'm not sure it's that simple. Can someone help? I am going to be running 30% Byrons with either 9% or 11% lube.

Also, does anyone know what piston/sleeve/con rod I will need once it's time to rebuild?

Thanks guys!!

I'm running my shark stock, no shims added. There is no reason to run 30% for off road, all it does is make the engine run hot and hard to tune. I'm running 20% O'donnels speed blend with a extra ounce of caster oil added. I got the advice on nitro content and the oil from one of the top tuners in California. My engine had a smooth idle, no flame outs and nice throttle responce. Use any 20% with a little extra oil for security, you don't want to be popping that pricey engine. 30% nitro is a engine killer, only go to 25% when you have trouble holding idle or flaming out. He told me to use 25 if i get to my third or fourth gallon through a motor.

Wow... 30% runs great and last just as long... what a way to say that 30% kills your engine.... no issue here...


as for the original question u can run 30%.. i would run 30/11...

that is a bunch of malarkey !

More nitro will make your engine run cooler, you will have more power, and you will use more fuel. Adding Oil to your fuel will make your engine run hotter. Yes it may lubricate more but it will create more heat.

I appreciate the comment...thank you. I gave my experience, if you have a different point of view, express it. Don't just call my way bullshit and run. Play nice boys and girls.

By the way, I run at high altitude and run 40% or 50% nitro. Have an RB with many gallons of high nitro run thru it and no failures. Engine life depends on the owner changing filters and tuning the engine.

Chris, you posted in between while I was writing. I was using 30% Sidewinder and couldn't get my motors running right, even blowing a on road RB classico 10. I switched to 20% with a ounce of caster and my temps went down 20-30 degrees and I didn't pop another rod.

I don't dought you, but I've had a different experience with 30%. I've asked for help on this forum because I don't know as much as most. The advice I've gotten helped me, and I've passed it on. If it's wrong and doesn't work for others, bad on me.

Sorry bro...didn't intend to be rude !

Adding oil increases heat...running 30% nitro does not wear an engine any faster, in fact engines should last longer... tuning is also easier on 30%... 30% requires you to run a richer mixture then 20%< which means more lubrication passes thru engine, also because 30% makes more power the needles do not need to be leaned down as far .......All in all I have best results with 30% nitro..... 20% does give better mileage and costs less money tho....