I used a medium length header. Top end improves nicely but you will obviously use more fuel. I recommend that you stay within the 5 min. refuel range.
good luck,
Roger

Right on, thank you.

HI Booker,

Mate i am running the VZR verII with the black speed crank and speed rod, and i chose to stick with the speed ceramic bearing, also using tornado fuel, the motor just keeps going and goes nicely,i run this motor on my club days and mate i will be honest, its the best mod you can do to the VZR, no more crank pin snapping of, or loosing the Rod, stick with the OS Speed ceramic bearing,in my opinion, its the best on the market. just keep in mind Booker using crap fuel will short live your motors internal parts,ie Bearings.

You can also look into the TKO ceramic bearings. I have been reading many offroad racers using them and having very good results. Price is much better than the OS speed Ceramic.

http://tkocompetitiondev.com/index.php?cPath=38_102

yes alot of offroad racers like TKO,and TKO do make a good quality bearing, but keep in mind the diffrent tollerences that the on road motors bearings take compared to offroad motors.On Road motors are sitting on higher RPM's consistantly compared to the offroad motors. so there is much more wear on the on road motors. but it also comes down to the quality of fuel. I have just pumped approxamtly 8-10 LTRS of fuel through my VZR with The OS Speed rear Ceramic bearing, and it is still going smooth.a friend of mine has a saying,and i stick by this saying "MONEY NEVER LIES" so pay that little extra on your RC gear and you will go a long way in racing with a smile on your face.

Cheers

Right on, your the first person that I have spoke with that has done that mod. I have my O.S. Speed rod and crakn still in the bag. I think I'm going to replace the P/S while i'm at it though, I haven't decided yet. Is there a noticable diffrence in the power?

You will notice a Tourquer motor, it isnt as snappy or high revy as most motors but it does move well, you will have to play around with the 2 speed to get it just right, i will be honest im only 1 sec behind the top end motors, but my P/L is almost 2 years old with hardly any compression with the plug in,and no nip with the plug out,but it still goes and doesnt flame out, im dying to put the new P/L in to test with the crank. The motor just wont stop on me, the best mod i have ever done to this motor, and im using a odonnell 99T glow plug. If you dont wont your Speed Crank let me know?

Cheers

ps, the 1 sec times was based on my last club day with the track conditions and low tratction,

I used a standard, out of the box .21 VZR at the recent Vic. state titles , the best lap I did in the semi final was only .3 slower than the winner of the A main.

Every heat the engine just got faster and faster, 5 minutes was easy ( I used a Novarossi 2015 pipe ) - added 0.1mm head shim and used a P7 plug.

I loved the linear power band , and to be honest, I didn't feel as though I was lacking power anywhere against all the more fancied names (GRP, RB, Novarossi)

I reckon stick a ceramic rear bearing in one of these, a little tickle with the dremel and in my opinion you'll be rapt ! ( have not done this yet )

These engines would have to be the best bang for the $ out there

hi ,
i am chasing a rear stock bearing in australia . if someone got one for sale or knows a shop that has them in stock. i would like to get one.
kind regards
alex

Hi SP,

Mate just keep an eye on that stock crank pin, because of the Backward design of putting the oil hole through the Crank pin and no oil hole in the rod, this causes the rod to let go, and also causes the the botton end bush of the rod to wear away and come loose. Yes i have to agree with you they are the best engine for bang for your bucks, but unfortantly for that bakcward desing they tend to GO BANG!!!, if you try the speed rod and speed Crank with rear ceramic you will love it even more, much faster and ever so relaible, i cant wait to run in my new P/L, the current one im using is 2 years old,all i just did was the mod that i mentioned to you and the fucker just keeps going.

Cheers

Rather than changing out the stock crank, stock rod and stock bearing on the VZR, why not buy the Speed Vspec engine?

yes that is another option, but the the stock VZR has a diffrent liner then the speed Vspec,

I'd like to see someone extract or press these into a block with out damage
These are designed for corrosive environments.

FYI,

Picco P7, P3 rear bearing is same size as VZ-R II. I already use it, fit flawlessly.

i just got a std version, i opened it up and was quite amazed at the crank and the liner. it is quite different to the Novas i have been running. i actually thaught about the design of this hole on the crank pin. to be honest i like the idea. its not really backwards, if one was to elongate the internal hole in the crank body, that would effectively double the surface area to channel the fuel to the rod. just my thaught, and with this to run a rod with the hole inthe rod also, this would double the amount of lubrication yeah ? the amount of metal around that crank pin, im sure it really hasnt weakened it too much ? there are so many factors why the pin might have broken on some engines, like hitting things on full throttle, screws coming loose, and jamming up drivetrain, etc, ill try it stock, see how it performs, but i will be making the internal crank hole a little bit bigger where there is alot of metal.