Hey hey.

I used to play with BMWs with M10 engines, SOHC timing chains. cam and crank to TDC - done. So here I am, all having never done a twin cam timing belt and ****. I am doing a TB/WP on a spare engine to swap in and would just like a confirmation that I haven't ballsed this up please

I have 19 teeth between the 2 pulley marks as I am allegedly supposed to. I can't count total teeth as the bottom pulley obscures them, but I have 39 on both sides from the bottom of the cam pulley to the top of the crank pulley so I believe it to be symmetrical. The arrow on the crank that aims at the notch is off a poofteenth, maybe 1/4 of the way off centre but it doesn;t show in the pic as it is not from directly in front. With the harmonic balancer on, it seems to line up to the left one of the two notches (96 engine if that makes a difference)

I have the 2 vertical marks on the cam pulleys apparently at 90 degrees to the head but it is a bit hard to tell. the markings at 4 and 8 o'clock look to be close but rocking the engine back and forth obviously moves them. everything 'appears' to be lined up with the front cover on.

Engine was turned over half a dozen times and the tensioner set before I checked and photographed.

So, feedback from brains trust appreciated before I button this thing up. I really would rather not have to dick with this in situ if I find I ballsed something up!

thanks!

 

Looking at the pics from my phone but it looks right to me

 

Put a wrench on the crank bolt and turn the engine over clockwise two revolutions and stop right at the crank mark without moving counterclockwise at all. Then look again at the cam marks. This is the only way to be certain that it is perfect once everything looks like it is.

 

What sixshooter said. Made my life a lot easier once I did that because I ended up looking at things and doing/redoing them way too many times...

 

ignore me - thought it was off but checked some pics and it looks right, just can't see the cam lobes.

 

THIS ^^ is about all that's left to verify.

 

thanks guys, had a long day at work and just got back in from dicking round in the barn.

I followed sixshooter's advice, last night I think i overshot and wound the engine back, so made sure i ran it forward then stopped it dead.

Also slackened and reset the tensioner.at 1 5/6 turns to be sure.

THey appear to be lined up on the sprockets using a straight edge from the bolt centres.

Cams are horizontal pointing outwards on number 1

Only concern I have is that when the 2 sprox are lining up with the marks on the backing plate, in order for them to be spot on, the timing mark on the crank pulley is on 2* ATDC. if I have it set to zero, the marks on the pulleys are not quite centred, but that extra 2 degrees gets them bang on. Pics below taken with crank set to 2 ATDC.

I am leaning on there maybe being some pulley slip on the rubber, or inaccuracies in the stamping of the plate etc, making it off a poofteenth? I figure if the belt was off it would be by a tooth, and with 24? teeth that is like 15 degrees and I am nowhere near that - same with the pulleys, if they were off a tooth I'd expect them to be further off.