just a wee bit gen if your gonna fit an 18e head to a 20 seh or ne, use a 20 seh headgasket not the 18e one, cos it wont seal, but 20 seh valve stem oil seals dont fit an 18e head, so i`d either buy an 18e top end set and a 20 seh headgasket, or do a sneaky and swap the headgaskets at a quiet place in the shop.
if you want to retain motronic managment you can, i`m told you shouldn`t use 18e injectors with motronic as theyre meant to be a lower impedence, but i measured both sets and they were 16 ohms. i fitted the motronic injectors anyway, so i could retain the calibras fuel rail, cos the 18e one was fouling the black conduit that the injectors connect to. if you have a later car (m1.5 as opposed to the earlier ml4.1) you have to make a bracket for the potentiometer to fit where the switch used to. measure the resistance with the throttle closed on the original throttlebody, then fit the pot to the new body, set the resistance to the same value as before with the throttle shut then screw it down with a couple of washers to spread the load.
on a calibra i had to modify the throttle cable slightly to get it to fit right, but i dunno if an astra need the same doing.
if your reatining motronic block off the dizzy vacuum pipe.
errr, what else, oh aye, retain the 2 litre top half of the head as the 1.8 one doesn`t have the breather on the front, but swap the cams over, and use the 1.8 rockers, i think pete r had a bit of bother with them
when doing that it would be the idael time to clean out the lifters, pop the ring off them and just pull them apart and wash the components in petrol till there clean. then reassemble
It really does make a difference. the owner of the car was dead chuffed fitting a part off an older, smaller car actually made his faster
*/Edit no need to cut the lugs if you just fabricate a wee bracket.
i forgot to say, to use an 18e cam in a l3 jetronic or motronic car you have to epoxy on the rotor arm and plate to the cam. its the only way theyl fit, unless you use the 18e top half of head, in which case youll lose your breather.
anyway some nice pics to look at.
a bit more torque, good gain throughout the rev range, but not earth shattering. much heavier throttle pedal, no downsides i`ve noticed. it pushes you back in the seat harder, which must be a good sign, but still not as quick as a tuned 16v. sounds a bit sharper too. maybe more gains to be had if you went the full hog and used le jetronic managment too, you could give loads of ignition advance and have no rev limiter.
the owner says its worth the £75 he paid me to do it all in.
(btw the owner knows his rotor arm is epoxied on, dont think i`m being unprofessional)
What did you start with, a seh or an ne?
Iv had ago with porting my own head, which should be back on today or in the next few days, and if i made a mess of that, then this is my next plan. Might also upgrade from ne to seh ecu/cams, but might not work very well with a wide ratio box.