i think its a rebuilt motor.....seen this same question in HT way way back in the day. when they rebuild it they recode the block.
btw i have a BNIB water pump and timing belt if your interested for that motor. my buddy left it with me after he got rid of his 86 crx si. i have pics if your interested....cheap...good parts from foreign parts collection when it was in business back in the day on buford hwy. 40$ new parts.
oh wait....looks like you may have a prelude motor in there or something....but i do remember a question in HT that was something along the lines of a kid asking if he had some prototype motor in his crx. they told him it was a rebuild like i said and they change the block code for identification/warranty purposes
BT 2.0 12V SOHC PGM-FI 1955 110hp@5500rpm 114tq@4500rpm 86 Accord LX1/Prelude si