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-   -   RB Concept Engine Thread.. (https://www.rctech.net/forum/offroad-nitro-engine-forum/251409-rb-concept-engine-thread.html)

tc5 man 05-03-2011 11:13 AM


Originally Posted by Sarky (Post 9055271)
Hello tc5 man

Concerning your engine, you should have enough pinch and no play in the conrod after such small tracktime. Did you check your air filter? Maybe it eat dust... The best way to check it, is to pull the engine apart, and check the crankshaft. If it's all scratched (like you would use direct sandpaper on it) at the admission, the engine ate dust from the filter or the fuel, and it doesn't sound good... If not, check the crankshaft pin : if it's over 4.98mm you can still use your engine. If not, you will have too much play and probably break the conrod.

Feel free to contact us anytime



hum, well i always keep my filters cleaned and oil so that whould be weird so i just take the backplate off and get a calbrater and measure the pin or do i have to take the whole crankshaft out i never done that ?

the engine starts up right away and i used a heat gun on the engine .
i actually had to use my heat gun to start it up since it was sitting for while.

Nick411 05-03-2011 01:42 PM


Originally Posted by tc5 man (Post 9055968)
hum, well i always keep my filters cleaned and oil so that whould be weird so i just take the backplate off and get a calbrater and measure the pin or do i have to take the whole crankshaft out i never done that ?

the engine starts up right away and i used a heat gun on the engine .
i actually had to use my heat gun to start it up since it was sitting for while.

My steps on taking apart a motor.

Before you get started plug all the holes in the engine and thoroughly wash the outside of the engine of all dirt. Soap and water works well for this.
Remove the plug
Remove the head screws
Remove the head and carefully put aside the head shims to be re-sized later
Remove the back plate screws
Very important! With the piston at the TOP remove the back plate
Pull out the sleeve,do not use anything metallic! If the sleeve is stuck, with the piston at the bottom, put a wood Popsicle stick from the front top of the motor down part way into the exhaust port, then carefully turn the crank so the piston lifts the Popsicle stick up against the inside of the exhaust port, this will then lift the sleeve as you turn the crankshaft further
Pull the sleeve all the way out noting the orientation you will need to reinstall it later
With the sleeve out slide the piston and conrod towards the back of the engine with your fingers only.it should pop off the crankshaft. You normally do not need to force this and should not need any tools.
Note the front and back of the assembled piston and sleeve so you can reinstall it properly later.
With the piston/rod out you can slide the crank out the back of the engine.
You may need to tap it lightly to get it started.
Remove the carb.

If you sucked dirt/dust it will be in every nook inside the engine. I would suggest washing every part with soapy water really well. Shake off the water then brake clean it all. Then coat everything in either wd40 or after run oil especially the bearings and crank.
Reassemble in the reverse order and try it out.

TIX 05-04-2011 03:42 AM

How does the fire11 go for run time. I'm considering it for a truggy. I have been tuning a b10 and I know the f11 will get lessbut how much less?

Sarky 05-04-2011 06:39 AM

The Fire 11 is a monster! It's the best motor you could find for the truck! It's delivered with a 9mm reducer but it's too much. If you use an oval 7mm, the fuel mileage will be around 10-11 on the truck, depending on the car, the fuel, the driving style etc.

Sarky 05-04-2011 06:40 AM

Also, I felt that for the truggy, the fuel mileage is sometimes better with the F11 than B11, because you are pulling less in the engine, which can improve the economy.

Chris Peralta 05-04-2011 09:54 AM


Originally Posted by tc5 man (Post 9055968)
hum, well i always keep my filters cleaned and oil so that whould be weird so i just take the backplate off and get a calbrater and measure the pin or do i have to take the whole crankshaft out i never done that ?

the engine starts up right away and i used a heat gun on the engine .
i actually had to use my heat gun to start it up since it was sitting for while.



I have a feeling the slop you are talking about is the rocking motion you will get when you put the piston at TDC. If you still have a slight amount of pinch when the engine is cold and the piston gets slightly stuck at TDC you will notice you can turn the flywheel slightly and the crank pin location may move from 11 o'clock to 1 o'clock when looking in the backplate opening.

If your rod is indeed bad you will notice you are killing glowplugs and the engine is flaming out. If it was running fine and was not killing plugs you should be fine. I have that same play you refer to in most all of my engines. If you always heated your engine I bet the rod is fine.

tc5 man 05-04-2011 11:29 AM


Originally Posted by Chris Peralta (Post 9061234)
I have a feeling the slop you are talking about is the rocking motion you will get when you put the piston at TDC. If you still have a slight amount of pinch when the engine is cold and the piston gets slightly stuck at TDC you will notice you can turn the flywheel slightly and the crank pin location may move from 11 o'clock to 1 o'clock when looking in the backplate opening.

If your rod is indeed bad you will notice you are killing glowplugs and the engine is flaming out. If it was running fine and was not killing plugs you should be fine. I have that same play you refer to in most all of my engines. If you always heated your engine I bet the rod is fine.







yup, that want it is its not eating glowplugs at least from when i raced last weekend and the engine never flamed out on the track it was staying running so it should be fine than.

yea, i heat the engine at first because my box cant turn it over but after that it starts up fine without doing that.

i will take the backplate off to see though if the crankshaft moves in that way your talking about.

i took off the carb and looked at the crankshaft and i dint see any straches on it from dirt or anything .

Chris Peralta 05-04-2011 02:06 PM


Originally Posted by tc5 man (Post 9061625)
yup, that want it is its not eating glowplugs at least from when i raced last weekend and the engine never flamed out on the track it was staying running so it should be fine than.

yea, i heat the engine at first because my box cant turn it over but after that it starts up fine without doing that.

i will take the backplate off to see though if the crankshaft moves in that way your talking about.

i took off the carb and looked at the crankshaft and i dint see any straches on it from dirt or anything .


Ya you should be just fine then, you would be killing plugs and flaming out if your rod was shot. I read your first post again where you said it has slight pinch at the top so I would say it's 99% chance that the play you feel is what I mentioned and is totally normal. Once the metal pinch is all the way gone you won't feel that, as it will be a nice fluid motion.

cow9527 05-04-2011 02:14 PM

thanks a lot. B10 is ready now for a race.

TIX 05-07-2011 03:07 AM

whats the difference between the shark10 and b11?
are they the same p/s/r?

rageworks 05-07-2011 04:43 AM

Can any of you RB engine gurus tell me what the difference
is in the 01163-14 and the 01164-14B crankshafts ?

Sarky 05-07-2011 07:24 AM

TIX: you are right, the B11 has got the same piston sleeve/rod than the Shark 10. The difference between those two are the crankshaft (different timings for better mileage and more torque on the B11) and the cooling head.

rageworks : the difference between those 2 are the weight and the timings. The 01164-14B is balanced on the plate with a small weight that the 01163-14 doesn't have. For more power, I would definitively go for the 01164-14B.

NitroKiwi 05-08-2011 04:50 AM

Hi there, the engine has loosened up nicely now, 1.5 gallons through it. I changed the gearing on the clutch bell (dropped a tooth) on the car too, it screams alright now but it's still running hot on an RB turbo 7 plug (135 celcius).

Should I pull extra the shim out? Will that help?

I know you guys had already recommended taking it out once it was run in but a lot of people are saying that with 30% nitro it's just too much compression.

I guess I just want to triple check.

TIA.

rbeamj 05-08-2011 07:09 AM

Nitrokiwi,

What are the temperatures like in your area of the world. Also the #7 plug is a colder plug.

As for running with 30% nitro, the instructions that came with the manual say to add 1 shim for 30% nitro, however here in the valley of california I have 3 engines, and several more from racers around here, that have never added the shim when running 30% nitro.

These engines are shimmed for 25% nitro from the factory and when you use the correct plug will run reliably for a very long time. Typically the #5,#6,#7 plugs are what are needed depending on temperature of your area. As for 30% nitro fuel I would personally not add the extra shim as I have had really good luck with 5 different engines going well above 9 gallons (I had one at 14 gallons and never even replaced a conrod that still ran when I sold it) on 30% nitro without having added an extra shim.

tc5 man 05-08-2011 11:47 AM

i, have a rb hobby 9 s5 and i run 20% im finishing off the rest of the gallon well i been wondering since people say that the engine is shimmed for 25% how do you think it would run removing 1 shim or is that not a good idea ?

im running a odonnell 77 plug meduim/hot.


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