hey! good to see some 8v enquiries
the 20SEH is the early version of the 2.0 8v. They were unrestricted by emissions laws, and so for starters, that made it a much better engine.
The main things are:
- ECU mapped differently
Inlet very slightly different (aperture sizes)
Cam has different profile (duration longer)
Piston tops have smaller 'dips' in them, increasing compression to 10.1
Slightly lighter con-rods and crank
All of these small things totted up to the 15bhp@flywheel. Not much, but in the car, the SEH is a far more responsive engine and a better base for tuning.
If you can find an SEH, get one of them...as standard...a much better bet to put in.
the c20NE was a replacement and toned down version of the SEH as the earlier engine would not pass the emissions laws regulated in 1992 (hence the C at the start of the engine code). This meant the 20SEH was phased out in 1991 when manufacturers were forced to implement the emissions guidelines. Not only was the compression ratio reduced, but so was the overall quality of the engine as vauxhall left the 8v to be the workhorse engine and concentrated on the 16v C20XE, the more efficient and naturally more powerful engine.
