Originally Posted by SOLDIER [X]
what makes u say this? any experience or second hand?
From a B20 buildup writeup:
In inspecting the block for structural integrity, the first thing I look for on a B20 is the quality if the aluminum casting that surrounds the 4-in-1 cylinder sleeves. Viewing the block’s deck, there should be no areas where the aluminum wasn’t absolutely flush with the bore casting, especially in the fillets between the adjoining cylinders. All B20 blocks are not created equally in this important area, and if the block isn’t “perfect”, broken cylinders are a certainty.
The cylinder casting that Honda uses in these B20’s is extremely brittle when compared to more resilient “round” individual bore liners. This is simply the nature of a casting such as this where sectional thickness varies so significantly. These cylinders are easily cracked if there’s just a hint of detonation and all it takes to break one of the blocks with the small casting flaws is about 220 HP, so they can certainly be a liability.
But yeah, my personal experience with built B20 blocks is rather limited (I'll admit that... I haven't worked on any shortblocks besides a Mustang 5.0), but thinking of it from a rational point of view, the B20 wasn't made to rev high enough to get lots of power from the top end, and the chief advantage it has over a B18C is the increase in cylinder bore... so wouldn't it be a better idea to use a stronger B18C block, and bank some money on oversized pistons and sleeves?