Morgo Big Bore Kit Triumph T120 Bonneville

Morgo Big Bore Kit - Triumph T120 Bonneville / TR6 Trophy / 6T Thunderbird

Part : MORGO1

Availability: In stock

Excl. Tax: £335.00 Incl. Tax: £402.00
Morgo 750cc Big Bore Kit for 650cc 9 Stud Models

Availability: In stock

Excl. Tax: £335.00 Incl. Tax: £402.00
*VAT Removed at checkout for Non EEC Members


Morgo Big Bore Kit for 650cc 9 Stud Models

Supplied with:

  • 1 x Morgo Cylinder Barrel
  • 1 x Standard Pistons Complete with Rings, Pins & Cir-Clips
  • 1 x Standard Cylinder Head Gasket (9.5 to 1)


Increases to 750cc

Suitable for Triumph T120 Bonneville / TR6 Trophy 6T Thunderbird 1963-74 plus any other Pre Unit 650 when using a 9 stud head.

Great for Tritons and Cafe Racers

Manufacturer's Description

Outstanding in Design and Performance the Morgo conversion is made to fit any 650c.c Triumph Unit or Pre Unit motor (9 stud head to be used on the latter) without any alterations to any of the standard parts. No reduction in bolt size or separate liners are employed in this conversion. The cylinder barrel is made from high quality cast iron, cast exclusively for us. The casting is one piece and only weighs a few ounces more than the standard barrel.

Supplied with cycle threads as standard. Fin area increased by 20% to give greater cooling efficiency. We have introduced a fin tower at each side of the barrel to eliminate fin ringing at high speeds and to give more rigidity. Also the fins are much larger to give added cooling and blend in with the shape of the cylinder head. Most important of all the strengthening pillars go up through the fins to give maximum strength to the base of the barrel.

Thread depth lowered by one full fin section to make available the possibility of removing top fin etc., for special purpose building without loss of thread depth, i.e., short stroke motors.

The pistons are manufactured in England by one of the world's largest piston producers. All pistons have cutaways for larger valves.

Standard compression ratio is 9.5 to 1 with a standard gasket. Alternative gaskets are available to give compression ratios of 8.5 to 1 and 10.5 to 1.

The standard range of pistons give the following capacities:-

STD 2.975in. = 740c.c. 45 c/ins.
PLUS .020in. = 750c.c 45 c/ins.
PLUS .040in. = 760c.c. 46.4 c/ins.

Care should be taken when using Thruxton Cams on valve to piston clearances.

Now after thirty one years production and continuous research this product is used by thousands of discerning enthusiasts throughout the world.

Additional Information


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