Meguro Works Racer : RR / RK

Meguro RR is a Works Racer machine built for the 3rd Asama Highlands Race's Senior Class 500cc competition held in 1959.
In the durable Senior Class 500cc, Mr. Tamura who participated in individual qualification (Clubman 500cc class, entry number 255) got on,
Even though we fought good, we had an engine trouble and retired at lap four.
There is also a record that Meguro RK (Clubman 500cc class, entry number 657-???) is also participating,
Information is scarce, and details are unknown at all.

The Meguro RK is an engine that seems to have been built for participation in the Senior Class 500cc of the 1st Asama Highlands Race, 
held in 1956 back in the year.
As its feature, it is a structure based on the JAP (UK) type engine which was present for auto racing then OHV mechanism was changed to OHC.
Single-cylinder 498cc, bore �~ stroke 82 �~ 94 (mm) of chain drive SOHC,
As a feature on the exterior, a style of the initial single cylinder engine with a timing cover diagonally, with timing and magneto behind it.
In lieu of the OHV push rod, a flat tubular cam chain cover is on the side of the cylinder and you can see that it is an OHC engine.
The engine actually used for 1st Asama Highlands Race is different from this.(RZA,RZB)
So, Meguro RK is a prototype in its development process, or it could be thought that it was a study.

The engine of Meguro RR is transmitted as being a newly designed engine different from the specification of Meguro RZ (OHC) 
which participated in the 2nd Asama Highlands Race,
From the photographs of articles published in the special journal article at that time, 
it seems that it used diversion or remake tune as it is performing the characteristics of RK.
Because of that, since the frame and the exterior follow the RZ, if the possibility of engine replacement is also possible, 
(Or use it after exchanging?)
I think that Meguro RK was used as a practice or spare engine .
Other details are unknown.




*** Principal statistics ***
* Total length : 2,260 mm
* Full-width : 710 mm
* Total height : 1,110 mm
* Distance between axis : 1,450 mm
* Weight : 175 kgf
* Engine type : RR (RK-?)type: Single cylinder OHC 4 cycle
* Entire aerodynamic volume displacement : 498 cc
* Installed capacity : Unknown
* Full speed : Unknown
* Fuel economy : Unknown
* Transmission : Advance 4 step
* Tire : (Front) 2.75�~19-4 / (Rear) 3.25�~19-4
* Starting system : Kick