(they're easily identified because they're closed deck, see picture below). These engines will only accept cranks that have 50mm main journals. These are the engines in early 90's Preludes and Accords. The H22a1, H23a1 and F22 blocks have 50mm mains. Here's the list of main journal diameters by block: While the more popular H&F series have 55mm mains, some of the early 90's blocks use smaller mains. MAIN JOURNAL DIAMETER: Of course there are exceptions. You'll just need to consider the bore size and the main journal diameter. For example, if you have an H23 crank, rods and pistons, but you don't have an H23 block don't worry! You can install that assembly into an F23, or and H22, or even an F20b. Just match your crank to your rods and pistons, then you can put that rotating assembly into any H&F series block. In the H&F Series world, since the deck height is the same for all H&F series it means that you can swap rotating assemblies easily. Why does this matter? Unlike B-series engines, which all have different deck heights and means they must use different length rods whether you're building a B16, B18a or B18c. Or F22 parts in an F23. You get the idea. If all H&F series engines have the same deck height, what does that mean? That means that you can put F23 parts in an H22.

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