I'm building up an L18 motor for rally purposes and am after some advice as to how i can achieve good low to mid range torque from this engine.

Any / all advice as to which block / head / cranks / rods / pistons / cam / headwork / valve sizes / etc to use along with any other recommendations to gain good mid range torque would be appreciated.

Cheers

a search will be very helpful for your quest.

what sort of hp/Nm are you chasing?

is it a street or a race engine?

what is the engine's general operating RPM?

there are lots of variables without a very descriptive requirement.

i mean, generic advice will only take you so far...

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frankenstein projects R us.

The Republic of Western Australia -
Propping up the Nation's Economy since 1901.

To get the most low and mid range torque you need to use a cam with high lift but mild duration. Large duration kills midrange.

Also need to keep air speed up by not having monstrous size ports etc.

It's always a compromise though, as you will lose top end power.

As pro240c said, we need some more info on exactly what you are looking for. How much HP are you chasing and how much $$$ have you got to spend.

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1971 Datsun P510 SR20DET 276 rwkW
2005 Mercedes AMG E55 350 kW
1969 Datsun P510 L20B EFI 95 rwkW
1975 Ford XB Fairmont GS Wagon 179rwhp
1980 Escort Van SR20DET unfinished
2002 Suzuki GSX1300R Hayabusa 185hp