What is the difference I have an h23a which is supposed to be a open deck compared to the h23a1 which is closed?

 

depends on the H23. the H23a or H23a1 non Vtec is a closed deck motor. Found in 92-96 preludes. the H23a Vtec motor found in the JDM Accord wagons are basically a H22a4 with a stroked bottom end. so yeah it would be an open deck.

 

What's the advantage & disadvantage of open deck & close deck?

 

Open deck is supposed to provide better engine cooling but is prone to creep under high levels of boost (around 15 lbs.). Anyone boosting an H22 that high needs to sleeve it, thus making it closed deck anyways. Another "advantage" to the open deck H22 blocks is that Honda gave the crank larger mains, making it safer for high revs.

 

getting an engine sleeved doesn't have to make it a closed deck block.

 

I dont see how open deck is better, other than it saves some weight. The closed deck engines are wet sleeve, so we have coolant flow 360degrees around the bore. Whereas, in open deck, there is no space between the sleeves where coolant cannot flow, this would create a hot spot.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AzCivic1.6 &raquo;</TD></TR><TR><TD CLASS="quote">getting an engine sleeved doesn't have to make it a closed deck block.</TD></TR></TABLE>

It doesn't, but most people that are building a motor are going to build it to handle more than they are going to push it, so usually people will make it closed deck.