Few days ago, UMA Racing announced their newest product for Yamaha Sniper.
its a new cylinder head, redesigned with bigger valves and optimized porting.
They call them UMA RACING SUPERHEAD.
This is the first racing cylinder head that is made from scratch!
as previously all racing cylinder heads are modified from the standard original head. Congrats UMA for doing a great job!
What catches the attention most is the claim of the manufacturer 28hp!!!
thats more than twice the standard horsepower of sniper
28 horsepower is equivalent to the kawasaki ninja 250 or honda cbr 250.
Few days after, Racingboy posted that in order for you to attain the 28 horsepower you need to also use
-UMA cylinder 62mm bore kit
They did not mention about adding racing camshaft, So that means if you add a racing cam
that will be more than 28hp, so probably more or less 30hp!!!
177cc engine with 30hp!!!
Due to limited details about the racingboy superhead I am intrigued to disect the uma superhead…
gladly i still have the damaged head of a sniper friend(sadam) for me to take pictures with
same point of view as possible from the product photo of racingboy superhead .
This is the comparison of the valves between superhead and standard head.
some say its around 24 or even 25mm intake.
another thing that caught my attention in the picture above is the two holes encircled in red.
What are those???
The timing chain side looks no difference from the standard.
Below is the intake manifold side. From the first look you can see the big difference.
the shape of the intake port is not round but split type round which the main purpose is to optimized
the delivery of air coming from the carburetor. Perfectly splitting it into two.
This type of intake port modifications can be seen in Yamaha race bikes cylinder head.
So if the uma’s superhead intake port is not round, definitely the intake manifold to be used will also be different,
We cannot use the stock manifold due to its round shape, air efficiency will not be maximized.
With that a special manifold must be provided by UMA.
The exhaust port looks like bigger than standard size of 24mm. Most probably its 30mm port
Of course since its SUPERHEAD, this must be ported ready, plug and play in their uma 62mm borekit and maybe uma racing cam.
We still have to find out once its sold publicly…
Stay tuned, ill post more info about this RACINGBOY UMA SUPERHEAD