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ej dohc to sohc swap


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from what i have read its possible to swap sohc heads (ej18) to a dohc ej20 n/a block.

this would allow me to swap an ej20 into a brumby without cutting the frame rails.

i know that swapping ej18 heads onto a ej22 gives about 11 or 12:1 compression ratio.....anyone got any idea of what the compression would be if the same heads went onto a ej20 n/a block?

 

(im disregarding the smaller valves and passages in the ej18 heads as i don't want a high RPM motor,bottom end and midrange are more important to me)

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forget the ej20, get an ej25 block and some ej22 heads. stock ej25 headgaskets will get you 10.8:1, and phase 2 headgskets much higher though valve clearance may be an issue.

no heads are going to help your low end like displacement will. besides I am willing to bet that ej22e SOHC heads flow a lot better at low RPM than ej18.

the ej25 has the same deck height as an ej20 so you are not sacrificing any width of the motor. just my 2c, I would not mess around with ej20 and ej18 stuff.

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i dont know what CR you would end up with but it would be higher than normal, and you might have to run premuim fuel. and how would the DOHC ECU and wire harness run the SOHC heads?

 

~Josh~

 

don't need ecu and harness if i get ej18 heads...i've got a distributor and inlet inlet manifold off a carbureted ej18....:banana:

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