The contenders in the ring have been loading up for quite some time now and Subaru has just upped its ante with an all-new boxer that is better in many ways over its predecessor but still sorely lacks as a modern-day engine.<b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b><b></b>
Subaru’s third-generation 2-liter boxer is essentially a sized-down version of the 2.5-liter lump in the new Forester as opposed to the force-induced EJ25 found in the current Impreza.
Dubbed the FB20, it takes a few small steps over the predecessing EJ20 but the overall length covered isn’t quite enough to get it on level footing with some of the new engines from other automakers. It features better power, emissions and even fuel economy but the absence of direct-injection asks as many questions as it answered.
Nonetheless, this doesn’t in any way mean that the FB20 isn’t something to watch out for, especially when it’s dropped in the Impreza. Subaru did get many things right, including the new compact and reshaped combustion chambers, chain-driven cams and ‘bent’ connecting rods that allow for installation and maintenance without separating the block.
The FB20 does sport a more squarish bore and stroke of 84mmx90mm over the EJ20’s 92mmx75mm, giving the engine more low-end grunt. The boffins at Subaru managed to do this without actually widening the horizontally-opposed engine. They managed this rather impressive feat by modifying the valvetrain and redesigning the block and head.
On the whole, the new boxer is more of an extensive refresh and revamp that an all-together ground-up redesign. It does address quite a number of issues such as increasing fuel efficiency by almost 10 per cent and reducing emissions but the jury is still out on why an all-new engine wasn’t developed.
Source: Autoblog
