90' crx si engine help

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dreapera

New Member
so ive been browsing forums for a few days and cant seem to get a definative answer to my question so here goes:

I just bought my first car a 90 crx si for 1800 it came with the stock zc engine and also a dohc head that has a distributor on the intake side and a cam position sensor on the exhaust side. there seems to be debate of which gen zc dohc heads will swap to which gen blocks and since i have code 9 and a oil leak on my sohc head id like to just go dohc with the new parts it came with. Any idea of what i need?
 
ok, so it is a swapped motor from the identification link you posted it is a second gen zc, its black top with a zc tamp on the block. but im unclear as to whether this dohc head the guy gave me with the car will fit on it.
 
take a picture of the block code, its either a d16a1 or a dohc zc, either or they should run fine on your a6 electronics , btw dohc d-series heads will not fit on a single cam block, the only difference between d16a1's and dohc zc's are the cams essentially, if it were me, id convert it to obd1 and run it on ls, electronics
 
Here's the engine as it sits in the car all stock wiring:


Here's the block code


this is the code on the head sohc that's on the block:


this head came with the car and is stamped hm just like the block but wasn't on the engine:
 
Here's the engine as it sits in the car all stock wiring:


Here's the block code


this is the code on the head sohc that's on the block:


this head came with the car and is stamped hm just like the block but wasn't on the engine:

a dohc d-series head doesnt have the same head stud lineup as the sohcs, it will not go on your block, you need a dohc d-seried shortblock ex d16a1 or dohc zc
 
a dohc d-series head doesnt have the same head stud lineup as the sohcs, it will not go on your block, you need a dohc d-seried shortblock ex d16a1 or dohc zc
actually, the only block that will accept the DOHC ZC head and bolt into the 90 CRX Si chassis is the DOHC ZC PM7 block - the D16A1 has the driver's side mount on the front of the block (toward the radiator), not on the end through the timing belt cover - without fabricating a mount, it won't bolt in - also, the transmission mounting bolt holes are slightly different on the D16A1 block requiring some modification to bolt the 90 transmission on and the starter mounting is different on the D16A1 (no hole in the block for the long starter bolt)

tegtimingcover-5_zps759367f5.jpg

tegblock3-3_zps08119b01.jpg
 
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