CB750 Big Bore Engine

Many consider it to be the first superbike and we still think it’s worthy of that title.

Having built strong race CB750 engines The “HULK” we know what works and how this unit responds to which modifications with our own Dyno facility to get the best out of every component and optimize power delivery and fuel efficiency.

CB750SOHC 836cc-850cc engines

The first step in our line of modifications to the OHC 750cc unit is a 12% displacement increase which doesn’t seem much but makes noticeable difference on torque values achieved by bigger pistons which aims at improving the engines torque figures which is what is most important for road use. You can send us your complete engine or just the barrels which will be bored and honed to suit the bigger forged pistons.

836cc Engine:

• Barrels bored and honed to accept the larger pistons
• Oversized pistons w/ rings – 65mm or 65.5mm

We offer the 915, 970, 1000, 1030, 1100cc engines.

These Engines involve:

• Re-sleeving of the barrels, sleeves available see products
• Crankcase machined out to accept larger sleeves
• H Beam conrods
• 67.5 to 75mm pistons w/rings

CB750 SOHC to 1240cc

• Re-sleeving of the barrels, sleeves available see products
• Crankcase machined out to accept larger sleeves
• H Beam conrods
• Stroker crankshaft
• 67.5 to 75mm pistons w/rings

These are one of a kind pieces of engineering where almost every component has been modified and improved to maintain reliability and achieve a very enjoyable and powerful engine with a very deep tone. Many hours are put into an engine build like this and the final product is a reflection of just that.

The biggest valves are used in the cylinder head with ports machined to match, the chamber is redesigned to improve efficiency, we will use our own custom designed H beam rods which are race proven, a stroker crank is used in the 1240cc engine while the 1100cc engines use the standard stroke, camshaft choices to suit purpose, the crank will be balanced and have the knife-edge profile.

Under request we can also perform other modifications to complement the Engine, including:

• Hotter camshafts
• Head porting to improve volumetric efficiency
• Bigger valves
• Heavier valve springs
• Race spec valve guides
• Titanium retainers
• Standard carburettors can be replaced by bigger, better units
• Performance 4 into 1 exhausts
• Ignition timing revised to suit all modifications
• Crankshaft machining to knife edge with lightening and balancing. This is also available on exchange basis see products
• Copper head gasket.
• Engines tested and tune in test bike before delivery.

Any other wear parts inside the engine (bearings, timing chains, retainers, etc.) will be inspected and replaced.

Our highest performance CB Four engines have made more than 110hp on our dyno with amazing torque figures as well from the increased displacement.