Since having the engine modified it has huge top end now compared to before.. (thank you mark from massive mods)

the engine was fast on the weekend just the pickup was a bit slow..next meeting im going to try a shorter 1st gear in my mugen mrx4 and see how it goes.

It could be your clutch setup John. Get J spec Jay to have a look at it, as he is an expert now. ;)

thanks Snowy
yeh its already been j-spec'd
i lost a thrust bearing in the 2nd qualifier and then jay had a look at the clutch setup again. the manual says to set theclutch nut to 1.2mm. I am at 1.4mm now so i might hav eto go tighter..

What's the top end on this engine compared to low rpm torque off road engines?

Won't the high revs cause premature wear on it compared to low rpm engines?

low end tuning..
 

hi guys
from the factory low end setting are you tuning the bottom end richer or leaner?

im trying to get more bottom end from the engine but my low end has been tuned richer from standard. the top end is great and it blow a little smoke from the exhaust with the plug a bit wet after each run.

Anybody knows the differences between the older vz-r and the ver II model?
I tried the parts list on O.S. site and it seems that the only ver II parts on it it's the crankcase and outer head.
osengines.com
If there are no other modifications on the ver. II why did they came up with it?

i heard they made some internal case modifications to make it go faster

They use the same case as the v-spec but i was wondering how much difference will the case mods make?
I mean the older vz-r was an average motor and for the ver.II they say it's much more powerful.
Are these just illusions?

i still believe its an average motor till i had massive mods modify it now it screams! and just keeps revving down the straight where it died out before

OS VZ-R II
 

There is a difference between the cranks on the first version and the verion II. I think it helped performance, and yes, it is noticeable.

Looking to get more runtime out of my VZ-r ver.II.
I used the T2060SC tuned pipe but didn't work well...good power but sucked on fuel efficiency.
JP-1 worked OK and gave me more than a min runtime...from 6 went to 7+.
Novarossi 9901 about the same as the JP-1

I use the engine for off-road racing and it doesn't lack on bottom end at all.
I installed 1.1 springs with teflon shoes and it works great.Low to top this engines can put out some power!!

My only problem is the runtime...WANT MORE:flaming:

Resurecreting a dead thread here. Has anyone seen or heard about a new OS on-road mill? After seeing the O.S. Speed buggy motors, I was wondering if the balanced crank and updated rod are going to pop up in a updated VZ-R. Now that Mugen is having their motors built by O.S., it would be a good time to update the on-road mill, maybe even under the Mugen name.

os vzr2
 

I have one and i only run 20% . I see that It has 2 shims under the head should I leave in both or take out one?

I put all the shims, and use 25% nitro ( close to sea level, humid and hot, about 33C to 35C )

I also use this on-road engine for off road :sneaky:, no problem.

Thanks for the resurrection of the thread.
I too have the new VZ-R Ver. II and run it in my MRX4-R. Down here in TX, we run a Spec series for the 1/8th on-road class and the VZ is one of the accepted engines. Our first race was rained out and we are scheduled to run this weekend. Throughout the break in period and some practice time on our track it has been a solid engine. This weekend is going to be the BIG test though. :nod: We are hosting a well known annual race , the Gulf Coast/Speedline Grand Prix, and we have 3 qualifiers on FRI, 3 more on SAT, then the mains on SUN. I bought a spare conrod when I got the engine - hope to leave it in the bag. ;) I have been running Rocket Science 30% Nitro :flaming: content in the VZ. Used the same fuel for break in using a ten tank system and did it in stock condition without additional shims to what was already in place. I have found the VZ to be an easy engine to tune. I also run an INS box and I have gotten extended run time. I hope to pit in the six minute plus range.
Let's keep this thread going and help each other with tips on this engine. Looking forward to any one's feedback.
Roger