exhaustvalves would be so awsome in theese engines

So would a reed valve. It'd be super interesting to see what the result would be.

yes a kind off exhaust valve ,,,a spring valve clape system can really makes the diference ,we were testing an inox pipe originally made for rc nitro boat which has a spring valve custom system ...so i mean by this way you can have a 3 chamber pipe at low rpms and at the same time a 2 chamber when it revs

Quite poor is my guess, a rotary valve is by far better. Getting reed valves to work at the rpm these engines run would be next to impossible, and nothing would be gained.

To be honest... Yes, there are tracks under fire of strong envirement laws needing to make low noise or even no noise (only electrics) but I do believe that amount is very low. I also know tracks were forced to quit due other projects on that ground which wrongly used as an example what can happen when making too much noise.
The EFRA is such an organisation I think responsable for too much noise. If they really had accapted onlty the pipes comply to their noise limit we would have low noise pipes for years but sadly the homologation fee is more importand than the noise level.

Now the EFRA is working on a noise measurement and changed the naming "homologation" into "registration", so the responsabillity becomes with the driver to comply with the noise limits. I think that is also why an ENS is attracting more drivers than an European championship because the ENS is not hanging onto noise levels.

What pipe is this that Jerome Sartel is running?

Rules are rules.... if you don't like the rules go play elsewhere... :-)

Looks like a 2041. Kinda' hard to tell, but if the stinger is perpendicular it's a 2041 Turbo. 2041's are very popular in Europe. One of the best all-round pipes ever IMO. I sold both mine, unfortunately...

Hard to tell exactly from that angle, but it could be a different Mielke pipe. Mielke-made though for sure..

Is the mileage better with the 41019 header vs the 41032? If so, about how much better? I'm assuming the 41032 is more powerful being that it is conical.

What is this I hear about the double bend headers can seem to lean bog at low rpm?

both of them are for top end and open tracks .i wouldnt use 41032 for off road ,,,,untill now i use it for gt cars ,,,i have seen better results with 41001 and 41005 at buggy and trugy ,,41031 and 41021 are also good choices ,,,you have to make a test in a middle track with all to find your favorite

Looking to run nitro this summer and I'm wondering about some motors for my buggy. I used a 4btt a few years back and loved it. I'm curious whats the differences between the 4btt, mito and the virtus?

I run on a medium sized track so Im just looking for the best runtime possible.

i just picked up a nova nv21b, seems to share some internals with the bf but has a 15055 crank wich i cant find any info on. i dont expect much for what i paid but has anyone else run one, the box says square stroke i thought tbe 3 ports were all stroked like the p5s.
oh well $100 with a crappy tuned pipe cant really complain.
EDIT Pulled backplate and the crank is extemely simple and has a pullstart pin attached. will the 15007t crank fit?

Can anyone answer this with any detail, it seems difficult to get any info on the virtus and Mito line of offroad engines for some reason

Not really. They're all here. http://www.novarossi.it/2012/index.php

Peer down into the engine page itself and it'll give detail and specs

and great place to buy is: http://novarossidirect.com/

So can someone explain specs in general? I can't tell from specs if a motor is supposed to be a torque motor, speed motor or good all around, etc.