ok so first off Ill tell you everything I know about this car/motor. Based on what I was told by the seller.
car-91 crx HF 387xxx miles. one owner up to 360xxx miles. older gentleman ordered the car brand new (ordered with cruise ac and foglights) car came with a folder full of work orders and receipts and even the original window stickers. seller stated that the motor had been replaced by original owner with a oem hf motor. HOWEVER upon getting it to the house today and checking some things out, things arent adding up. Ive been doing some research for a few hours and keep hitting a dead end. so hear it is, the block is stamped D15b (no numbers following the b) the head is stamped pm3-17 (my research indicates this is a obd0 si head. valve cover has spark plugs on the intake manni side and says 16v honda, no vtec solenoid but theres is a plate bolted to the head where a solenoid would be. car has HF intake manifold and throttlebody with the tiny air intake hose. it also has a td-18u dizzy which is also obdo si. Is this a frankenstien motor or is this some sort of jdm obdo single cam non vtec? thoughts comments, all is appriciated thanks

 

jdm d15 block with single cam ZC originally carburated head. the block off plate gives that away. if you take the valve cover off, youll see the cam has an extra lobe right at the end of the distributor side for the mechanical fuel pump.

the original HF engine puked and the shop or owner just threw whatever jdm engine parts in for cheap.

 

makes sense... what generation block is that? im under the impression that the jdm d15b vtec and non vtec were obd1, reason for asking is bc it needs a water pump and i guess i need to cross reference part #'s to see what pump I need. If i knew what obd it was it would narrow my search. thanks alot man

 

i think neither the block or even the head determine the obd. its the distributor and injectors. i dont think any of that changed based on what you said.

 

very true but i guess what i was trying to figure out is what the usdm counterpart would be for that block. read believe on dseries.org that alot of civic vx parts are interchangeable. trying to find a swap as we speak so i can do away with this nighmare of a concoction lol

 

the JDM D15B carbed model (which is what it sounds to me like you have) is essentially the same internally as the USDM D15B2 (88-91 DX/LX) - just had either dual carbs or single carb instead of DPFI - dual carb 98hp or 104hp and single carb 90hp - both the D15B non-VTEC carbed and the SOHC ZC carbed used the same head casting - the JDM D15B VTEC-E engine is the one that is essentially the same as the USDM 92-95 VX D15Z1, not the JDM D15B non-VTEC

 

you can pull the water pump n count the teeth to see which pump you need cant you?

 

yea Ill just take the old one off when I go to the parts store and try to match one up. Thanks for all the input everyone, very much appriciated