OS V-Spec vs RB C6BBT
 

Hi I am deciding on which .21 class engine to power my new buggy (Xray XB8EC). The RB engine is slightly more expensive at my LHS. Any much difference in their Power range, durability etc. As this is my first pro kit buggy i need some advice. Perhaps those guys who own these engines can share the experience with us. There are many of us out there who are deciding on a new engine for our buggy. Any comments will be greatly appreciated. Thank you.

the V-Spec makes a little more power ( dyno tested) but the C6 uses much better materials, so it will be more durable and last much longer...... by feel on the ground the C6 is just as fast as the OS....

I have never run a V-spec so I can not say anything about it. However I do know alittle about RB mills. I would sajest getting a WS7III. I have a WS7II and it has lasted a full year and is still going strong. The power curve is very driveable.

From my investigations, this is what I have found. Both motors are good motors there is no doubt there. The Vspec has better bottom end punch, but the c6 has better top end, but with that being said, you need a real long straight to see the c6 top end. I believe in a 200 foot test the c6 just caught upto the vspec at 180 then took the lead, but where do you have 200 foot straights? Most tracks you need good bottom end to get you throught the infield. I run Vspecs on my Buggy and Truggy. I would run a Vspec in my CRT.5 if i could get it to fit. LOL so I just have a 18tz. All OS for me. They hold a realy nice tune. And as far as the bearing issues go in the OS engines, you could pick up a tko ceramic bearing for like $30 and change it right away or wait. I changed mine right away on one engine and am gonna wait for the other since I have spare stock bearing now.

I have run both , and seen many others go of each , the RB C6BBT WILL MURDER A V-Spec if you can harness the power !!
the V-Spec is smoother through the middle to top so it may feel faster, The C6 will be blazing the tires from start to stop !! The C6 needs to really have a good pipe choice to use all it's power wisely and utillize the best possible fuel economy too.
So it is really up to the user , for a rookie starting out I would go with the V-Spec ,alot easier to tame and tune;):nod:

A thread like this will always start some kind of argument. Its a presonal prefference, both engines kick ars

The OS is good (yes I've used it) but the C6 has power to spair across the whole RPM range. Guys who tell you the C6 has less bottom end than the V-spec had the wrong clutch or pipe on the C6 (or both). In addition given the same care, any RB will outlast any OS.

the C6 does not have power like you guys are saying...common please..its a fast mill and all but its far from being the most powerful 21...it has average output for a .21...the dyno graphs show exactly what the mill makes... The C6 may have more snap on trigger due to the blunt tipped LSN as compared to the V-Specs constant taper.. its port timings and volume are very restricted from factory and its dyno results reflect this...to say a C6 blows away a V-Spec is completely unrealistic and untrue.. if the C6 had that kind of power it would show on the dyno ..Now when I re-time a C6 and open the ports up it turns into an animal..but in stock port timing trim its not anything special when it comes to output... not knocking the C6 but its nowhere near the animal you guys are making it out to be..Sorry to sound like a dick, but the C6 has never impressed me with power, the Picco P7 is to me a much stronger engine...

ive drove both motors.. and the c6bbt does have more power then the vspec. but IMO the BBT is way over priced and the vspec if u watch and check the right places u can get one brand new for 230. id say buy the vspec just because u can almost buy two vspecs for the price of one c6bbt...

I agree with RBMike.

Yes I agree the C6 is pricy but beleive me it will last way longer & make up for it.


As for dyno #'s, they don't tell you how the motor feels on the track. In addition most of the dyno #'s I've seen where taken with the wrong pipes.

rbmike makes some good points.. the RBs do last pretty well. and as for the dyno numbers im not sure on that.. the rb bbt feels strong from bottom to top with smooth transition. good luck on your purchase... id also think about the new ws7x3 with the turbo button and all in it...

Speaking as an engine modder i like the C6 and feel it has alot of potential to make big power , but I truly don't feel the stock C6 is overly powerful.. Looking inside the motor I can clearly see where the engine has been restricted and timing turned way down... the exhaust timing and configuration is heavily restricted, with the 2 eyebrow ports being responsible for 90% of the exhaust flow....... Anyways back on topic I like the C6 and definitely agree its a well made motor as well it has huge potential for making more power with the correct mods..... As i type this I am modding the sleeve on my C6 getting it ready for the Winternationals....

here is pics of my crank

http://i107.photobucket.com/albums/m...dcranks008.jpg
http://i107.photobucket.com/albums/m...dcranks007.jpg
http://i107.photobucket.com/albums/m...dcranks006.jpg
http://i107.photobucket.com/albums/m...dcranks003.jpg
http://i107.photobucket.com/albums/m...dcranks002.jpg

heres my Picco crank as well..

http://i107.photobucket.com/albums/m...dcranks010.jpg

Maximo looks like you do good work judging by those crank pics.

O, I forgot to add the C6 with a 2045 gets great fuel economy. At the indoor (winter track) I regularly go too, I get a reliable 12+ minutes at race pace from a "legal" 125cc fuel system in a buggy.