installing timming belt different between first time and sec

[markus_74]

hello,

does first time install timming belt method is different compare install timming belt for second time/service.

I read someone article in the website that if you first install timming belt it is not only that the camshaft gear have to align with the mark and also the lower pulley has align with the mark but after install timming belt I should rotate the crankshaft a few times to check that the piston and valve not crash/slap?

does is it true? the writer said that because it is 4 stroke engine so sometimes the mark not align after a few rotation.

or if all mark has in the perfect position Ionly have to install the timming belt and it is done?

this is the position of my engine.


this is the position of my camshaft

[Speedtouch]

http://www.e30zone.net/e30zonewiki/inde ... elt_Change

http://www.e30tech.com/forum/showthread.php?t=1889

[toby]

It's a checking procedure really.

Line up the timing marks.
Put the new belt on and turn the engine over by hand from the crankshaft
(camshaft spins 2 rotations and crankshaft once).
The timing marks should still line up after you have turned the engine over.

[Cloggy Saint]

I had a similar experience after changing my belt. First time fitting everything was ok but then I realised I had the wrong water pump fitted so had to remove and replace everything again. After giving the crank 4 rotations the cam marks lined up but the crank was just slightly off. There's no way either pulley was moved during installation so I left it and it doesn't seem to be causing any obvious problems.

[markus_74]

if after checking procedure (turn the crank 4 times) and then the mark is great move/not perfectly align. what should I do?

[toby]

If the timing marks don't match up take the belt off, replace and line it up again.

[Cloggy Saint]

So if the marks are out as little as Markus' what effect would it have on running?

[maxfield]

So if the marks are out as little as Markus' what effect would it have on running?

No. Sometimes you will find a belt won't go on perfectly timed.

Some modern cars won't run being a tooth out.

[Brianmoooore]

There's no 'fine adjustment' with a M20 belt. It's fitted so as to get the pulley marks as close to the fixed marks as possible. The situation is made worse if the head has been skimmed at any time.
On the other hand, the later M40 engine has a cam pulley which is just an interference fit on the cam nose, so can be fine tuned to get the timing spot on.

[markus_74]

there is no cure?

I mean may be I take the head off from the block and turn only the cam 1 more times and put it back to the block it will cure or not?

may be some rotation on the crank or cam individualy can make some different effect?

[gromgsxr]

adjustable camshaft sprocket if you want to get is spot on.