Heres some stuff i know about CA's n then ill write specific area mods, tips or problems
*Alot of $ were spent by Nissan during development to get the right combination and the SR20 was made because of the high productioin cost of the CA18
*Either CA18DE (nonturbo) or CA18DET (turbo)
*Early Silvia/180SX
*All 180SX are Turbo version only
*Cast Iron Block
*5 2bolt mains
*Cast strenghening girdle around mains to prevent twist
*(DET) Oil Squirters are located below cylinders to cool the pistons
*Valves are directly activated from the camshaft unlike SR20 which uses rocker Arms
(DET) T25
Direct fire coil packs located over cylinders in head
***Parts***
Luckily many parts are avalible from the australian delivered nissans which had the FWD CA18DE
*Gaskets
*Therostat
*Water pump
*(note flywheel is different number of bolts so not compatible)
*Aparently the ecu can be used also but minus some of the important sensors that the DET has
Silvia/180SX parts are genrally easily avalible from most import part suppliers (Getting them to seperate them off their complete engines is sometimes harder)
***INLET***
*2 pieces (Upper and Lower)
*Jap spec have Inlet Butterflys which open during light throttle
*Kiwi spec have no butterflys and a slightly different head
These are seen to be a waste of time and many have removed them completely as their more restriction being there. i think the Kiwi ones just go into the head as four ports while the Jap model heads have 8 ports into the head.
FWD uses Jap Inlet but main throttle body is on the oposite side of the manifold
Sensors and valves on Manifolds are:
*AAC valve
*FICD Solenoid
*Air regulator
*Thermostat on lower manifold
*2 coolant tems sensors on lower section behind thermostat
***HEAD***
*The heads are generally ok and if you plan to get it ported go for around 50lb of air flow
*Hydrolic lifters
*If you rev your engine above 8k go with solid lifters cause the hydrolic ones stick and can cause valve or piston damage... if you get solid lifters you must also use a solid camshaft
*Ajustable cam gears are avalible
*Coil packs often fail due to the high heat in the head so swap to a remote setup and run the spark under the cover with short leads
*Get head match ported with your exhaust so you dont lose any kw due to bad airflow
*DET injectors are 370cc there are many types that can be used, they are top feed so the GTiR pulsar ones which are 440cc can be used but not Silvia series as they are side feed
*Stock head Gaskets are brittle crap and many CA's are scrapped due to head problems... alot of the time its just a head gasket, geez i wouldnt even throw out a a12 with a stuffed gasket they aint that hard to change
* Go with a aftermarket one like copper or multi layer steel, there are also Felpro composite ones which are rated at (3bar)
If you got the head off always use new head bolts from Nissan, as far as i know ARP ones arnt avalible but i heard u can use RB ARP bolts???
For a High performance engine things to look at also are springs, retainers and valve guides
***Block***
*Standard pistons dont like high boost
*Detonation will destroy your pistons and this will intern ruin your bores and crank, if it plays up tow it... dont hope it will make it home as it may but your wallet will end up empty
*Can be Stroked there are heaps of kits out from major japanese supplyiers like Tomeii or HKS, ive heard of one 2.1 litres but i dont think you would go any bigger due to the sleave thickness
*Forged pistons are suggested
*Rods if prepped are good for 8000rpm
*Forged are avalible so depending on budget
*Crank apparently can handle 95000rpm if prepped
***WATER & OIL PUMPS***
Apparently CA's suffer from cavitation which is bubbles in the fluids which isnt good cooling wise, im still trying to suss this out so ill let u know when i know
***Throttle Body***
XF falcon will not fit without mods
theres others like the Nissan Q45 but i dunno bout getting them on there if you go bigger check the manifolds to see if you need to port them out
***TURBO***
*CA18DET is T25, SR20DET is T25G larger housings both internal wastegate
*Many bolt on from same series like T28BB
*Maybe VG30 with modified manifold cause the stud pattern is different
*Stock is water and oil cooled
*Stock manifold is ok but there are many aftermarket ones avalible
my fingers r sore so ill post more later