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Os .21 VX-B(P)

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Thanks again Nitroaddict. :)
I have a Hyper 8 port. So your comparison puts things in perspective for me. :) Better top then the 8 port? Sweet! I'll be getting the VZ-B(P) next week then. :hehe:

Tex
 
Update:
The engine is getting close to broken in 10-12 tanks.
Every-time I start it up it just gets faster. I installed the second head shim that OS packaged with it. Doing so lowered the temps about 10-15 degrees. I'm still running way rich around 210-220 on an average with WOT runs up to 235 at this point.

I broke out the CyberMaxx with the Hyper 8 in it and ran it to get a comparison. I must say the Hyper has the Way low grunt power to move the Maxx but after that there is no comparison in the two Mills. The OS The OS lacks the lowe down and dirty 3 ball grunt of the Hyper 8 but but thats it. The OS is quality through and through. When I start the two of them up at the same time just the sound will get you. Its like listening to a hillbilly hot rod sitting next to an Italian road car. The OS shines in the mid lows all the way up to the High Highs. This fat lady Sings!
 
Originally posted by TexSavage
So how does this engine stack up against say a WS7II or P5?

the ws7II and the p5 are buggy racing engine. we have guys at our track that run both of these engines. these engine are know for their grunty bottom end (awsome acceleration).

This OS Eddy is playing with is optomized to high end. You really can't compare the WS7II & P5 with this OS engine. They are built for different purposes. If you want acceleration, the P5 and WS7II will beat the OS. In the long run, however, the OS may beat them in speed. Make any sense?

If you're going to bash, you just want the raw speed to hit the jumps and get fat air. If that's what you're doing, go for it.

-Rob
 
All right. I got my VZ-B(P). :dance:
Here is a question for you OS users. Is OS for real about the 18% oil content? The only fuel I can get locally with that much oil is for airplanes. What fuel do y'all run in your OS mills?

Tex
 
TexSavage,
You do not have to run a fuel with 18% oil in it. Any of the quality fuels made specifically for cars will work.

Rob H,
I have to disagree with what you said. I have ran a number of engines, and the V01b and VZB are known for their torque. They have never been known for top end, the WS7 and WS7II will walk it on the straight. They are race engines, period. You don't win the world championship with a basher engine. The P5 is probably a little stronger on the bottom and on the top after it is fully broken in. The RB's have always had more top than the OS's, but have lacked a little on the bottom when compared to the OS. If the V01b or VZB does not have more bottom end than any of the S7 series engines it is either (a) shot and needs a rebuild or (b) whoever is tuning it does not know how to tune their engine. With the right pipe, clutch, and head the OS's will provide a ton of torque. Also, the OS's have the smoothest power band of any engine I have used. I've had 3 V01b's, a P5, and my brother has ran a S7, WS7, and now a WS7II just so you know I'm not pulling this out of my ass.
 
Ok I am looking to replace the port race and the O.S. .21VZ-B (P) looks like the way to go. I am racing on a tight track with short run ups to the jumps if this helps. Would you say to go with that engine or some other brand/model? Any tips on a good place to get them with good prices? One other thing what's with the third needle thing will it be harder to tune than the older ones?

Also what about O.S. .21RZ-V99 with short shaft? Would it work and is it a good engine if I can get one at a great price?
 
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hey eddy u were talking about the head shims? i have 1 in my xtm 24.7 right now and it runs pretty good with temps around 250. will it lower the temps if i put the second one in?

bryan
 
All right. I started breaking this bad boy in. 1 quart down so far. OMG is this engine tight! Forget about starting it without pre-heating. Stalled my Ofna blue box in a heartbeat. And the included A5 plug. It's a nice gesture. But I had to switch to #8 just to keep it running at the initial super rich settings. Not to mention I had to keep the heat gun on it the whole time. The engine wanted to run at around 140 degrees. I had to help it out a little to stay in the 180+ range.

But I am getting there. I can tell this one is going to be a screamer. :hehe:

Tex
 
Originally posted by FlyinRazorback

Rob H,
I have to disagree with what you said. I have ran a number of engines, and the V01b and VZB are known for their torque. They have never been known for top end, the WS7 and WS7II will walk it on the straight. They are race engines, period. You don't win the world championship with a basher engine. The P5 is probably a little stronger on the bottom and on the top after it is fully broken in. The RB's have always had more top than the OS's, but have lacked a little on the bottom when compared to the OS. If the V01b or VZB does not have more bottom end than any of the S7 series engines it is either (a) shot and needs a rebuild or (b) whoever is tuning it does not know how to tune their engine. With the right pipe, clutch, and head the OS's will provide a ton of torque. Also, the OS's have the smoothest power band of any engine I have used. I've had 3 V01b's, a P5, and my brother has ran a S7, WS7, and now a WS7II just so you know I'm not pulling this out of my ass.

I appologize. I was comparing the v01b to VZB. Tower has their RPM vs HP rating different. After reading on the RB site about the tricks people have to do to get more bottom end on their 7-port engines, I can clearly see that the 3-port beast that is the OS .21 engine clearly has the advantage down low (both versions). I'm looking into getting a new engine for next season. I'd like to have a v01b, but it has been discontinued. I also heard a rumor that the new O'donnel influenced VZB is having some durability issues. I hope they straighten it out because the OS is lookin pretty good otherwise.

-Rob
 
The HP ratings are garbage.

There seems to be some durability issues with the VZB as you have said. Seems the sleeves are wearing prematurely. Several guys are replacing the billet piston in the VZB with the cast piston from the V01b. After they do this they aren't having any problems. This is the main reason I went away from OS. When and if they get this fixed then I may check them out again.
 
Anyone know where to get one of the older V01b???

And whats with the port at the rear and under the carb??
osmg2065.jpg
 
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robr, I saw that OS at my lhs today. I'll give more info if ya need it, let me know.
 
What do you mean boost? Like as in a turbo for a 1:1?? Does it provide positive airflow into the combustion chamber? Please splain.
 
robr - that is a built in boost bottle. i have two of these engines. when u let off the throttle quickly, some fuel will still flow to the carb of a nitro engine - then when u full throttle it again, it has to burn that unspent fuel before taking off, so there is a small lag. this prevents that from happening.

Robr - my LHS still stocks plenty of these engines. i can get them for 260.00 plus tax
 
tower claims they have them in stock but limited quantiies:

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXALM0&P=7

This is the non-(P) version which means you'll have to get a clutch nut adapter. I don't think this is a big deal. NA hobby shop is cheaper too. It's hard to find them new on ebay, but it's still possible.

My main concern about buying a "disconintued" engine, is finding a new p/s, conrod, wrist-pin, etc when it needs a rebuild. I'm sure the VZB parts would fit the v01b, but then you get into the billet vs cast piston and back into the premature p/s wear.

I hope OS moves back to the cast piston from the billet piston. That would make the VZB worth it.

In the meantime, RB's WS7II is looking pretty good (with the right pipe) but finding parts for the RB engines is a bitch in the states. Waiting for a head shim to ship from France just so I can run 30% just doesn't tickle me.

I'll shut up now, I'm de-railing Eddy's VZB thread. :opps: :sorry:
 
RobH - Welcome back!!!!

the VZ and the RZ are almost the exact same engine, so alot of parts will fit. also - if u check out the OS website, u will see that they stock parts for up to 20 years. of course, the problem with the bad boy os engines is parts cost. when i replaced the piston, rod, and sleeve for my RZ it was almost 180.00
 
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