O.S. VZ B .21 Engine???????
06-08-2006, 11:24 AM
#1
O.S. VZ B .21 Engine???????
I recently got an o.s. vz b engine but the connecting rod is gone. Can anyone that has had one of these engines give me some info on it? Is it worth fixing??? How fast is it compared to other engines??? how long will it last??? Any info will be greatly appreciated 
06-08-2006, 01:13 PM
#2
It is one of the fastest engines on the market. As long as the piston and sleeve are in good shape it would be worth fixing. However, it is not one of the most durable engines. If you are looking for something durable then go and sale what you have and look into purchasing a nova rossi n21bf. You should be able to get a good $100+ for the case,piston,&sleeve if they are in good condition. The n21bf doesn't have as much top end as the v-spec, however it will out last it and its still a very good motor. Either way you go purchase a heat gun to give you more engine life.
06-08-2006, 02:15 PM
#3
I run a VZ-b. It's basically the same engine as a V-Spec except for the standard plug (not turbo) and slightly different exhaust timing. If the crank pin is still round I'd replace the rod. You could always get the piston and sleeve renewed at OSrocket.com for $20. The crank will be more expensive to replace than is worth it.
06-08-2006, 02:59 PM
#5
Wow, my personal experience with O.S. motors has been completely different. I've had several, in almost all my airplanes, and several of my cars. They've all been excelent/smooth running, reliable, and had plenty of power. However, you can over-lean, and destroy one, just as you can with any other motor. I've had a couple Novarossi motors as well, and while they were fast, they were finiky. I'd have to tune those things a couple times a day, I rarely touched any of my O.S. motors mixture screws...I set'em and forget'em... If I were you, fix the O.S. for cheap, and see how you like it. If it's too far gone, ditch it and get a new one.
06-08-2006, 03:28 PM
#6
Tech Master
iTrader: (14)
Those were all my previous experiences with os engines too. I had 2 standard cv's that ran and ran for 2 years without having to be rebuilt. I still use my rz-v99b in my 1/8 scale. Doesn't have the power, of new motors, but it does run great. I am just hesitant to buy a v spec because of the problems people have had with them. I don't want to drop $300 on it and have it last 2 gallons.
06-08-2006, 06:38 PM
#7
The problems you've read about only seem to have happened to the early run of engines. I've been racing mine for almost two years and way more than 2 gallons (more like 6 to 10, I lost count because I race multiple classes) and I finally had to replace the p/s. Everyone I know that races this engine has had excellent results. The bearings in mine are original and still fine and with the new JP modified p/s/r the old engine just rips.
06-08-2006, 08:01 PM
#8
The problems were caused by two things. People not using a heat gun. The crank shaft will get messed up if you don't heat these engines up. The other is an improper gear mesh. If the mesh is off it can cause extra stress on the bearings.
06-09-2006, 06:07 AM
#9
Well the bearings are ok and the motor does seem to run fine but either the crank pin or the connecting rod are gone because you can see there is alot of slop when you turn it over with your hand. Would I need a new crank or connecting rod??? Or both??? Also, How to take these things apart??? I only know electric motors lol.
06-09-2006, 06:55 AM
#10
Ryan, if the engine has not taken in any dust/dirt then your rod is most likely the only damaged part. Take the crank out and use a digital caliper to measure the crank pin in 4 places around it's diameter. If the 4 measurements are close to the same (really close, like .0005") then your crank is still good. If the measurements are off then your pin is ovalized.
Ospower, how much do you want for the crank and carb?
Ospower, how much do you want for the crank and carb?
06-09-2006, 09:44 AM
#13
Take off the head, turn the engine so that the piston is all the way up (this is important, if you don't you could break the bottom edge of the piston). Then take off the back plate. You will need to carefully remove the sleeve next. A good way to get it out is to turn the crank so the piston is back at the bottom and use a tooth brush handle or popsicle stick (domething softer than aluminum) and insert it in the exhaust post then turn the crank so the piston pushes against the object in the poet and puches the sleeve up. Once the sleeve is out the piston is free to move enough so that you can get the rod off of the crank and pull the piston/rod out the top. The crank just slides out of the back of the case.
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