angreed also with 22 racer, vp fuel has only bad news and roumors ,werks is good quality fuel. there is sometimes a diference of what we want to use fuel for ,profesionaal use ,club racing ,bashing and having fun.stability and runtimes are winning races .most of us we need long lasting engines .tessman was using vp power master 25 but he has the ability of changing parts and engines when ever is needed .....:)

Hi guys,

My brother is currently running a Nova PLUS.21-4BTTSWC. How does the new Nova Mito 4 and Rex Legend 4 compare to this engine?

Thanks in advance!

I have never owned a WC - but it's a pretty well respected motor, and the last of the real ballistic motors. It also uses a regular bearing, so bearing changes are much cheaper.

The Legend 4 is the evolution of what he has - much smoother and more toned down. Uses the weird expensive bearing.

The mito is a much longer stroke.

So a BTT and a Legend 4 are nearly identical engines, they have the same piston and sleeve but have different crankshafts... The Legend 4 has a onroad style crank with a large bore and double tungsten slugs whereas the BTT has a offroad crank with a smaller bore and no slugs..... Sometime in the next little bit I plan to dyno test my Legend 4 and will swap back and forth between a BTT and Legend crank to see what the difference is....generally speaking the larger bore crank has a smoother throttle response but makes more power and RPM...but usually a crank like that is in a engine with higher timing and more aggressive porting, so we will see what the results are...

Neal, is there any timingdifference between thoose two cranks?

VP and Werks are mixed in the same factory. Pick your poison.

Just a comparison you can make with the parts to see if you really want to try it..


4BTT
http://www.novarossi.it/2012/index.p...4btt-wc_a.html

http://www.novarossi.it/2012/images/...-4BTT-WC_A.pdf

Legend 4

http://www.novarossi.it/2012/index.p...-off-road.html

http://www.novarossi.it/2012/images/...GEND-4-OFF.pdf

MIto 4

http://www.novarossi.it/2012/index.p...-off-road.html

http://www.novarossi.it/2012/images/...MITO-4-OFF.pdf

the same....i will of course update if I am wrong...

A big thank you to Socket, Maximo & kgombe for the detailed info.
Looking forward to seeing the result of swapping those cranks!

Hey Rex, got my Rex Revenge this week. Great looking engine, started breaking it in today. Awesome deal for the money..

Hey guy yesterday during racing I lost the rear bearing on my vir-tus 7port. Less than 4 gallons in. Anybody else seen this. Just seems odd to me!

well.. I just want to ask.. were you running Nitrolux fuel?

Byrons 25/8

I have not used 25/8 but have used 25/9. 25/9 eats engines for me. I stopped using it and only use 25/11. I advice to use 1-2% of Byron lubebooster ( castor oil )

IMG_1547.JPG
Found it.

The worlds blend is great for bearings however rust is not

Come on guys!! Rear bearing would be OK to make 4 gallons on any fuel blend !!
My thinking goes to lean High speed needle or accidentally dirt intrusion on bearing.

I always try and keep a slightly rich tune. If I go lean it's almost always the bottom. But that's rare. I feel comfortable about tune and fuel. I'm just wondering if anybody else is having trouble with this bearing? At 132.00$ a bearing I don't know that I want to order one, or just replace the whole motor

Here is how many revs the bearing have done, if you take an avarage of 8 minutes a tank over 4 gallons (16 liter) and set an avarage rpm of 20.000rpm.

8 tanks a liter X 16 liter X 8 minutes a tank. Thats 1024 minutes of running.

1024x20000=20.480.000 revolutions not bad, is it?

Considering I have an OS and a tko ceramic in it with 9 gallons on it and it still runs with little work. I would say it pretty much sucks!

Novarossi Direct has them for $89. I forget offhand, but TKO or one of the other bearing companies might make a 14,5x26x6x5,7x4,7mm bearing also for even cheaper.

These special made bearings are only sold by Novarossi with a very special price.

When it comes to Byron 25/9 vs 25/11, the bearings has a lot shorter lifespan with 9 than with 11 percentages oil. A mix of both is the perfect blend

So beyond fuel another thing I know kills bearings is aggressive triggering under no load...Rapid spikes in the engine RPM will cause the balls to skid instead of roll, and once the balls start skidding they start creating flat spots on the balls and or channels in the outer race, once it happens once it can happen easier the second time and easier the third time.....Bearings are especially vulnerable when the engine is cold....obviously combine this abuse with a low grade lubricant and the issue is compounded.. I have worked with several drivers who have a nervous trigger finger and they are always hurting bearings..either out of nerves or anger rapid hits of throttle while the tires are off the ground is a very bad thing for these engines...

TKO's site says they have the special bearings for the Novas. I think about $40 or so a piece.

Got a link? Doesn't matter how I search it still doesn't come up

Here you go

http://tkocompetitiondev.com/product...lkeep-off-4-2/

My bad... Roelof is right.

http://novarossidirect.com/16006_p_2238.html

The keep off bearing is a 14mm, the Virtus needs a 14.5

I wouldn't have thought fuel would be the major corporate here at 4 galons it just seems too early, I was going to make the switch to byrons 30-9 but now I don't think I will reading the responses here about this issue even though I think it's more than just a fuel issue at 4 gallons there must be something else that's gone on and if the OP has a speed with 8 or 9 gallons on it could just be a faulty bearing or dirt/grime. Maybe you could share some pics of the bearing if available so we can see what it looks like. Novarossi are kind of reminding me of Apple and their iproducts with their bearings not being available anywhere else out there but from them .Can anyone manufacture this bearing if they chose too? They would probably alter something else when that happens anyway, I mean you can look at it like smart business or poor business I suppose depending on your view of it, me personally I don't like it and think they would sell more units if replacement bearings were readily available atleast at the current cost of them anyway it's rediculous like Op is saying he is already contemplating just swapping the mill out for something else at this point already. Man I'd be bummed wether it was poor maintenance on my part or not I still wouldn't be happy.

Low oil content like 8% is ridiculous for anything but a 1 run World title A main engine. Those who are saying castor are 100% correct, even if it is only in my experience. Engines run cooler, more consistent and last... to the point where I decided to run in a new engine because I was bored with the old one not dying, at 45 liters. Done that twice now, still got the other for backup ready to go...

I would gladley use 8% oil in my fuel if i could have blended it myself with the oils i have been recomended by som very good guys i.e fuelmakers in Europe.

These special bearings do not add a thing to performance and milage as Novarossi wants you to believe. It is marketing to sell replacement bearings for a high price. And because it is patented I think other manufacturers have to pay a lot for making such a bearing.
But maybe there is light at the end of the tunnel. Last onroad worlds was won by Kurzbuch running a special Mito 9C which is now introduced as a Mito 35. This is a Flash based engine, so a normal longstroke (16.8x16.2), no special bearing and and no offset carb. It looks like Novarossi is going back to basic.

If you have the machines you can modify a normal 14.5x26x6 bearing, take it appart and grind the inner race a bit smaller.

Another thing which is easy to do with a lathe is to take out the dam inside the crank case, I have it done once.
http://www.rctech.net/forum/onroad-n...gs-virtus.html

The dam preventing the placement of a normal bearing:
http://www.euronet.nl/users/tooms/bearing/lager3.jpg

And after a few minutes work:
http://www.euronet.nl/users/tooms/bearing/lager5.jpg

The engine is just running the same with a 20 dollar bearing :D

I don't for a second believe I would be faster running 8% than 12% or something, just like I am not faster running 30% nitro to 25%. I do believe my engines would have less longevity, and less margin for error.

If you are at a level where you measure consistency in 0.1 second intervals, you probably would be faster and you wouldn't care about the seized bearings and destroyed conrods that these threads are filled with.

4 gallons is standard for an engine. Usually when u run it with safe tune (slightly rich), it will last more than that. High quality fuel is recommended and most important is you know how to tune. Bearings usually will last throughout engine life span till loss of compression. Proper break in + good tune = bargain

YES.

Quoted because more people should read this.

thank you sir

i dont have any pics of the bearing but it did have some slop to it..

this is the first engin I have had any trouble with before 6 gallons. not saying I'm an expert by any streach. Had I known the S storm it would have started I would have never asked the question. prolly will never ask again either.

Just add some castol oil for fully synthetic fuel to make it safer to run...

Tune for good power n not extreme power, most motors dont do 10minutes unless u try to be extreme

Pipe springs needed for PLUS 21-4 BTT / 9901 pipe / 41021 Header
 

I bought a brand new Novarossi PLUS 21-4 BTT, new 9901 pipe and a used 41021 Header that was a back-up for a friend of mine. I didn't get the pipe springs for the engine to header or from the header to pipe. Can someone give me the part numbers to the right length springs for this combo?

Thanks . . . Matt