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-   -   Ninja Engine by GRP (https://www.rctech.net/forum/offroad-nitro-engine-forum/95814-ninja-engine-grp.html)

gashuffer 02-18-2007 10:55 PM

They are threaded, very cool :D, When are you sopposed to change your conrods? two gallons? My .21A is holding up very good so far with 2 gallons through it. I've been runnin about 230-240.

mdelosrey 02-18-2007 11:10 PM

So the heads for the Falcon's is Magnesium or Magnesium look?

gashuffer 02-19-2007 10:20 AM

I believe they are the real thing. I skeptical of magnesiun though, brittle at high temps?

Pooh2 02-20-2007 01:53 PM

Looks don't matter much 2 me. The Ninja kicks ass!!!!!!!!

sohlman 02-20-2007 07:54 PM


Originally Posted by gashuffer
They are threaded, very cool :D, When are you sopposed to change your conrods? two gallons? My .21A is holding up very good so far with 2 gallons through it. I've been runnin about 230-240.

Which temp gauge are you using with your Ninja? With an Exergen, temps should be around 270-290. You may never have to change your conrod if you are running lower temps. The A has a stronger conrod, so it will last longer. But to be safe, I'd inspect it carefully for excessive play around the crank and pin, then decide. :tire:

PROVK 02-20-2007 08:11 PM

What percentage nitro is the MR21-R01A shimmed for out of the box
and why do you get a extra shim.
I will be using 25% fuel.

Thanks

gashuffer 02-20-2007 10:25 PM

I added a third shim because there was so much pinch I couldn't break it in smoothly. I run 30%.Wow 270-290? that scares me, I can't afford a new engine that quickly :D thanks sohlman

gashuffer 02-20-2007 10:42 PM

Exergen :sneaky:

T. Thomas 02-21-2007 04:37 AM

gashuffer, with the design of the head on the Ninjas, the exergen is closer to the plug than other heads. DO a little test, get the engine up to temp then take a temp with it down in the head and then raise it to where it would be flush with the top of the head. You should see a 30 degree change or so. That difference is why people say run it at 270ish because when you take that change away it drops it down to about 240(if a normal head was used with a hole that the temp probe wont go into) which is where most other engines run at. As long as you have smoke coming out in every corner and you still see a slight haze at the end of the straight at full speed, the temps are not a worry. Only time they should bother you is if they are unreal high, like 350+ and there is no smoke coming from the pipe exiting corners or at top speed.

sohlman 02-21-2007 05:02 AM


Originally Posted by T. Thomas
gashuffer, with the design of the head on the Ninjas, the exergen is closer to the plug than other heads. DO a little test, get the engine up to temp then take a temp with it down in the head and then raise it to where it would be flush with the top of the head. You should see a 30 degree change or so. That difference is why people say run it at 270ish because when you take that change away it drops it down to about 240(if a normal head was used with a hole that the temp probe wont go into) which is where most other engines run at. As long as you have smoke coming out in every corner and you still see a slight haze at the end of the straight at full speed, the temps are not a worry. Only time they should bother you is if they are unreal high, like 350+ and there is no smoke coming from the pipe exiting corners or at top speed.

Exactly right T. I ran my Ninja at the Nats at around 300-310 deg (with Exergen) and it ran great.

jaykay 02-22-2007 03:19 PM

Tomorrow I will get my. :D I´m realy curious about, how the performance will be.

I hope it will be the same like my Plus 12-3 :D

sohlman 02-22-2007 05:28 PM

I heard a little rumor...the MR12s are in stock at Mugen USA. :nod:

HarKonnenD 02-22-2007 05:30 PM

Are the older plain ninjas still ok to buy or should I wait for the ones with new heatsinks and or ceramic bearings (if there is a version with them).

sohlman 02-22-2007 05:46 PM


Originally Posted by HarKonnenD
Are the older plain ninjas still ok to buy or should I wait for the ones with new heatsinks and or ceramic bearings (if there is a version with them).

They never offered the 12s til now. So this will be the first version available to the public.

The 21s are all fine. Ceramic bearings are a great upgrade to any engine, but not always needed if you want to save some loot.

HarKonnenD 02-22-2007 06:01 PM

Gotcha. So the Ninja that been wining some of the events were modifieds I assume? I trying to recall if Swauger been using a stock or modified Ninja. I'm in a toss up between them and the Sirio STI which I've been watching some of the locals beginners using as I helped them tune it. Hopefully there will be some at the WRAM show on sale as I'm still a bit skeptical of the ZX12s crankshaft issue. The ones they will sell aren't the 06 version.


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