Crankwork

k it looks almost identical to the 21-5k factory tuned i just got. thanks

Novarossi Tuned Engines have the crank bored out a little more, the turbo flute is more aggressive and they change induction timing.

still trying to figure out why novarossi didn't epoxy fill the cranks

Probably because it's not necessary.

Hey Guys
This has probably been asked before, but how does the P-4 compare to the
21-5K. I have narrowed it down to buying either of these two engines to
replace my buggy's ageing P5SX. The P-4 is Novarossi's hottest new buggy
engine and the 21-5K I heard is also a great engine and on sale for slighty
less than the P-4. Your input and opinion would be greatly appreciated.

I am getting way too many opinions on pipes! Can someone suggest a good match. So far JP-3 is leading. I race at the Nitro Pit

9901 hands down, 2nd choice would be 9853

Don't know for others tuned pipes but I'll run mine with the AE Factory tuned pipe in my RC8 and RC8T.

I know the 21-4 works with a Sirio 2013 off-road tuned pipe set very well. Rips everywhere, low, mid, & top with good fuel mileage.

What kind of run times we talking, and venturi, if any

Hi, I run the 2013 pipe and no lie I get 14 min run time and thats a little on the rich side, I pite a 12 to 13 min. :eek:

Plus 4 is MUCH better than 21-5K (or KT). Believe me ;)
Here in Italy 21-5 has never been considered so much...Plus4 is THE engine now here...

T, we can stuff a ceramic bearing in it.:nod: Maybe a 15min main, no pit stop, :lol:!

ok guys ill put my two cents in here. just got done running a hot mod plus 4 last nite. i also have a protwister mod 21-5k in my stable. hands down the plus 4 rips. blows the 21-5k outta the water in my book. dont get me wrong i love the 21-5k, to me its better suited in a buggy where as the plus 4 is better in a truggy. now on pipe selection. i am a big fan of the 2013. personally that is about all i run on all my NR engines. now the plus 4 i ran last nite, i ran it in a buggy and put a dynamite 086 pipe on it and actually went up a tooth on the clutch bell to try and tame that motor down on the bottom end. im running on a really tight indoor track that i normally run a 12 tooth on. so ive said all this to say..... 21-5k good strong motor, plenty of power nice and smooth. run either the 2013, NR 9853 or 9901 pipes. the plus 4 on the other hand i would run the 9853 with the short manifold. but any of the 3 pipes i mentioned for the 21-5k would be good. i really liked the 086 on it but the only problem that is wen it got on the pipe...IT GOT ON THE PIPE!!! it would just break the tires loose goin down the straitaway on me. any way thats just my 2 cents and it personally is up to you and your driving style