How to set valve timing on 1995 Daewoo Nexia DOHC?

Answer 1

Answer and some wise wordsI found this out the hard way: knackered the head and then worked it out from basic principles. The info on the internet is all wrong (or at least does not apply to the 1996 DOHC 16V 1.6 Nexia I have) The AllData manual I got from a mate's uncle in the trade was also wrong - it said the inlet cam mark should be at 3 o'clock and the exhaust cam mark should be at 9 o'clock, so they are right next to each other looking at the side of the engine where the cam belt is. It then said that the crankshaft pully mark should be at 6 o'clock. If you do this you will break your valves & pistons and maybe more. There is a timing spike that sticks out from the engine block at about 2 o'clock looking at the crankshaft pully - the pully mark lines up with this when the cams are at 3 and 9 o'clock as above. This worked for me, but see below too.

I learned a few things: You can of course (with the head off or by looking at the bottom of the pistons up through the sump) work out the timing (approximately but accurately enough) to see where the marks should be. And where they should be there will be a very obvious timing mark/spike on the engine block or head cover or something or at least a very obvious alignment of marks with each other. You know, when the #1 piston is coming to the top and the inlet is just opening and the exhaust is just about closed then that is the end of the exhaust stroke and then the intake stroke is about to start - well get the crank and the cams about there, then rotate keeping them in sync and you will see what I mean. Put the pully and cams in the right places (approx) before putting the head back on - less likely to bump piston and valve that way. Turn the engine over a number of times (the cam goes clockwise/forwards) by hand - you should only have very slight resistance from the pistons compressing air (so only twice for a rotation of the crankshaft pully). If you get hard resistance that seems to be from the cams when turning the crankshaft you have got the timing wrong - the pistons are bending the valves. Do not do bolts that go into the aluminum head too tight. To get the pully and cover on/off - just crowbar the engine over a bit. Oh yeah - those half moon shaped dents in the top of the pistons - that is to handle the valve overlap.

Hope that all helps

The crankshaft pulley mark on the timing cover is for the drive belt pulley, the mark at 6 o'clock is for the crankshaft cog (behind the pulley),there is a small dot on the crankshaft cog which lines up on the small mark on the small bottom timing cover. When changing the head gasket to prevent damage to the valves turn the crank back to the 3 o'clock position and when the camshafts are lined up (inlet 3 o'clock exhaust 9 o'clock) turn the crankshaft clockwise to 6 o'clock.