h22a1 open or closed dock?

[DRob's Cb7]

I just picked up an h22a1 block with a crank. And I can't tell what has been done(if anything) to the block. Like sleeving or some thing. And an 87. Mm witch is stock bore.

[deevergote]

Closed deck. That looks unmodified from what I can tell.

The H22A1 is closed deck, the H22A4 is open deck.

This is an A4 for comparison:

[wagon.spec]

What's difference between topen and closed.

[deevergote]

See the space around the cylinders on the H22A4 block that isn't there on the H22A1 block? That.


Open deck is better for cooling, but not quite as strong. Most engine builders that do serious internal mods to an open deck will close the deck. "block guards" are commonly used things, but IMO they're total crap. They're essentially pieces of metal that fit into the space to brace the cylinder walls. They can shift, and they can cause distortion of the cylinders.

[wagon.spec]

So the a1 is just stronger?

[deevergote]

In a way, yes. Stock for stock, there's no real difference... but the open deck design will likely reach its limits faster than the closed deck design when power is increased significantly. Granted, in that case, forged sleeves should be used in either case.