that this works really well up to 9700rpm.
‘ You definitely need a 9-litre sump with baffles and trap doors – all that kind of stuff – to keep the oil around the pick up where you want it. And for the extra capacity too, because the pumps are high volume, they’ re going to be moving much more oil around. We’ ll get a standard core and we give them to a company here called High Octane Racing. They have their own cast extension because the OEM sump is a cast aluminium. They weld their extension on, which has everything built in.
‘ If you’ ve got something that you’ re going to spin at 10,000rpm plus, and you’ re going to make 1500hp or something crazy, then the dry sump is your only solution.’
Amazingly, to achieve such wild numbers, many of the RB’ s original components can remain.‘ A close friend was making 1100 or 1200hp with a factory RB26 crank. He spun that engine to 10,500 or 11,000. They’ re proven to work. 9000’ s not a problem for an OEM RB26 crank. 1000hp is also not a problem.
‘ RB30, same sort of deal.’ The 3-litre block used in the single cam Nissan Patrol and made under licence by Holden for the VL Commodore.‘ We do a 1000hp-rated twin-cam RB30 engine that we’ ve been doing since 2005. We won’ t turn them as hard, so I’ ll maybe go to 8800, 8500rpm. I couldn’ t even tell you how many of those engines we’ ve got out there making 1000hp with the factory RB30 crankshaft.
‘ The limit of the OEM crank realistically is the bearing width. With 1000Nm, the factory bearing width was okay. You start making 1100, 1200, 1300Nm, then you start to see accelerated bearing wear. If you tune the engine and you make bucket loads of torque and you try to bring everything on early, that’ s when you start to overload that bearing. When they’ ve been overloaded, you get a very particular wear pattern.
‘ Nitto designed wide journal 2.8 and 3.2 crankshafts. The wide journal has changed things; it’ s night and day. We can push the engines harder. You can make more torque earlier.’
The factory block needs no modification for these to fit.‘ Bang it in there. You don’ t have to modify the block. You don’ t have to do anything. It comes with the right conrods to suit. We don’ t even change the pistons. You change the rods and the crankshaft. Obviously, put a new set of rings in it because we’ re going to give it a freshen up, give it a light hone and it all goes back together as it was.’
Not everything is perfectly suited to such high revs.‘ The big problem with the RB is harmonics. Harmonic balancers are very important. I’ ve found that ATI Performance is the best for dampening those harmonics and stopping everything from falling off and breaking. You get to a point where you can’ t do anything about it. The harmonics are so bad that the longer the stroke gets, the worse it gets. The ATI balancer runs O-rings inside it and it’ s designed to be rebuildable.’
The RB26DETT’ s oil pump is the engine’ s only real weak spot, many of its components can handle much more power
Winter 2025 The Engine Rebuilder 27