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Ricci's Garage

Ricci's Garage: is it wise to give a rebuilt R34 1,000bhp?

Actually, don't answer that. But the method for doing so is fascinating...

Published: 20 May 2024

Internationally renowned photographer Mark has been working with TG for many, many years. When not taking photos he’s buying inappropriate cars. Here he shares his addiction with the world...

Modern car configurators love to boast about the customisation they offer. Performance aero, bigger wheels and an infinite number of paint codes are all commonplace, but this tends to stop the moment you get into something techy like a car’s powertrain.

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“Excellent choice on the yellow over purple stitching. Have you thought anymore about what thickness head gasket you’d like to run?”

Because clearly letting every customer muck about with their engine’s insides would be a recipe for disaster. Aside from plunging a business into financial ruin, giving people free rein of exterior colours is scary enough without letting ’em near important things like compression ratio or cam profile. There’s a reason that engineers are kept under lock and key without sunlight.

Unfortunately, this is exactly where I find myself with the GT-R rebuild. After the last engine – which was supposed to be the last engine – turned out to be a dud, this final attempt at a semi-reliable, big power RB26 is now coming all the way from Australia. And how it drives, along with how it makes the power, is all on me to figure out. No pressure.

Thankfully I have Anthony Dahler of Dahtone Racing as my GT-R life coach, and with Dahtone responsible for some of the world’s fastest Skylines (often exceeding 1,300bhp), safe to say there’s no better person out there for ensuring the R34 GT-R never needs another engine. Ever.

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After chatting with Anthony about the kind of power and use needed from the GT-R, we settled on an engine spec capable of running at around 800 wheel horsepower. In ‘traditional’ horsepower that’s around 1,000bhp, so barely breaking a sweat for what the Dahtone boys are used to building.

What exactly does a semi-reliable, big power Skyline motor look like? Well, unsurprisingly expensive. But then again this is an engine which only ever produced 276bhp from the factory – doubling or tripling that understandably takes more than a zesty exhaust and a remap. The only ‘stock’ part being used is the RB26 block, but even that has to be very specific for Anthony and his team.

This is where it gets a little bit nerdy. Standard RB26 bore size is 86mm, and typically if you’re increasing the displacement (or just rebuilding a stock motor) you tend to oversize the bore by around 0.5–1.5mm. The problem is, this weakens the block significantly, which is why Anthony has insisted this stay at the stock 86mm size instead for maximum reliability.

The displacement is increasing up to 2.8 litres, but that’s achieved through a new crank, con rods and pistons rather than actually increasing the size of the bores. Stronger internals, more displacement for increased torque and all without weakening the stock engine block.

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And it doesn’t stop there. Every seal, gasket and fastener will be replaced. There’s an uprated oil and water pump, different cams to allow the increased airflow and double valve springs to prevent valve float north of 8,000rpm. It’s what I should’ve done a long time ago, and with the rest of the GT-R completely out of hand it seems only fitting to do the same with the engine.

If I’m lucky, it should be good for close to 1,000bhp with the right turbo and fuelling.

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