Vekta.5 engine

[Bspoon]

I’m stuck between two engines the Red Arrow 34cc and the OBR 34cc Signature Series for a Kraken Vekta .5 which one is better recommended and why ? ... Thanks

 

[John Parks]

Cant go wrong with either really. I have the OBR reed stroker 34cc and love it. I know many with the red arrow also and they love it as well.

The red arrow engine is a non-reed engine though, the OBR is a reed engine.

 

[Buzzsaw46]

I know two guys running the OBR34 reed and they are incredible mills.

 

[Bspoon]

Okay now what’s the difference between a reed and non reed ?

Cant go wrong with either really. I have the OBR reed stroker 34cc and love it. I know many with the red arrow also and they love it as well.

The red arrow engine is a non-reed engine though, the OBR is a reed engine.

 

[evssv]

Reed=more power

 

[Z.hb71]

Okay now what’s the difference between a reed and non reed ?

Reed is a one way valve that goes in the crankcase like in this photo vs a non Reed (aka piston port) just attaches to the cylinder head.
Piston porting is a compact, economical, and effective intake system for a low to medium performance engine. Some very effective high performance engines have been built using piston porting but they suffer from intake reversion and have a very narrow effective RPM range.

Reed valves are bulky, expensive, cranky, and require intensive flow study for maximum performance. However, current Moto-Cross engines are producing in the area of five HP per cubic inch. Figures I have seen on a 125cc was 37 HP at 11,000 RPM. Tuned exhaust can cause a reed valve to flow while the exhaust port is open and the reverse pulse pushes the fresh charge back into the cylinder giving a supercharge effect. If I am not mistaken this was pioneered by NSU about 1960.

Many of the larger model engines use reed valves, they have a much better power band width.