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Head and Barrel

The new Challenger head and barrel are produced from brand new moulds that we have produced and are to exact measurement. The head has been spigoted so that it sits in the barrel by 3mm therefore making a perfect seal between head and liner(no more horrible black oil running down the fins!). The combustion chamber is polished and accepts a short reach plug.
Head and Barrel
When we embarked on having the Challenger barrel produced we spoke to several people in varying disciplines of motor cycling. To give you, the customer, more scope to work with we added 8mm to the external of the transfer port area so the barrel can be "worked on" and the porting played with to give you the ultimate performance.
You could if you wish, shave the back end away, cut the inlet port and fit a four petal reed valve. No other Challenger barrel will let you do this because:-
  • There is not enough aluminium in the barrel
  • The old barrels did not have enough material round the port areas therefore DMW and DOT barrels would only let you do this on modification
The porting of the barrel has also been worked on. The sharp corners have been removed and re-shaped so that the gas flows better. The porting is as the works bikes in the 70's.

the liner is counter bored into the top of the barrel by 11mm. the top hat liner is fitted after boring. The liner, as can be seen from the picture, is thick enough to reduce noise but also allows rebores up to +80.

Pistons and rings are also available ex-stock. If you would like an engine with performance, you have it in the new Greeves head and barrel.

The head studs are top quality dural aluminium. Washers, crankcase studs 0.25 wht x 0.25 wht. Swan neck manifolds that cool the fuel before it enters the cylinder are chromed.

Amal concentric carburettors 26mm to suit manifolds and air filters are also available

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