Morgo 750cc Big Bore Kit

£407.50 ex VAT


Outstanding in Design and Performance the Morgo conversion is made to fit any 650c.c Triumph Unit or Pre Unit motor a 9 stud head has to be used on Pre-Unit engines  Can be fitted without any alterations to 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 in the UK. The casting is one piece and only weighs a few ounces more than the standard barrel.

Supplied with cycle threads as standard, UNF threads to order only. 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.

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 9 to 1 and 11 to 1.

The standard range of pistons give the following capacities:-

STD 2.974in. = 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.

First produced in 1969 and with continuous research this product is used by thousands of discerning enthusiasts throughout the world both on the road and in competition.

Technical Information

Weight 10 kg
Dimensions 36 x 25 x 30 cm

All 650cc Triumph Twins with a 9 Stud or 10 Stud Head. 10 Stud are special order contact us for details.


1 x Morgo Cylinder Barrel 2 x Standard Pistons Complete with Rings, Pins & Cir-Clips 1 x Standard Cylinder Head Gasket (9.5 to 1)

Compression Options

9.5:1 (Standard), 9.0:1, 10.0:1, 10.5:1, 11.0:1