mark28

need little advise on timing an engine ..... 406 petrol 2.0 1996

autodata book says put pins (m6 bolt will do ) into cam pullys to the lock cams. then lock crank pully with pin (m8 bolt will do )

ok the problem is that when pistons 2&3 are at TDC, the valves on the inlet cam for piston 2 are open (fully) .

so the timing pins must be in the wrong place?? or the autodata book is wrong???

there is a cut out in the cam pully, and there is a cut out in the camshaft. sooooooooooo which one do i put my timing pin in??

i cant see it being the one in the camshaft as you cant get to in when the pully in on.

any idears anyone

Normski

I've just been putting a timing belt on an Mi16 motor this afternoon.

With that engine the crank is in the correct position when all the pistons are half way down the bore (and a drill bit can be inserted into the timing hole).

Remember that the crank turns twice for every turn of the camshaft(s).

There are timing holes in the camshaft pulleys as well (I use drill bits), with corresponding round holes in the cylinder head.

When all three drill bits are in, the engine is in the correct position.

mart360

sounds like your 180 degrees out......


in theory, you can lock the cams anywhere, as long as the relationship between the cams and crank stays the same, and then just replace the belt..

try turning it untill you find a position where all the locks go in.... then just change the belt

Mart

mart360

Alternativly...

cut the belt length ways as you turn the engine over, (so you have a half width belt) then slide it to the back edge of the pullys... then push the new belt on, so it effectively hangs over the pullys (by half again).. then cit the old half belt off. and then push the new belt fully home, whilst slowly turning the engine....

belt on with no need to lock the cams


mart

johnnyroper

if you are at tdc on 2&3 and inlet valves on 2 are fully open then something is wrong inlet should only start to open when piston is going down or you would end up with bent valves
reference previous post on 406 1.8 &2.0 16 valve engines when crank is locked in position no 1 & 4 pistons should be tdc with all valves on 1 & 4 fully closed
if i were you i would turn engine over by hand get no 1 to tdc then see where cams are and make sure valves are fully closed on no 1 if all is ok what i do is mark up sprockets with white paint and cable tie both cam shafts together to stop movement and than proceed to change belt you can then turn over by hand and see if they all line back up
this is all presuming that it is running now?

34srm

peugeot 406 2 litre petrol pistons are half way in the bores thats right they dont time up at tdc

mark28

thanks for your input

ok so in that case then my crank is out! when you have the crank in the correct place is the timing pin hole at the top of the pully and in line with top of engine?????

i have never done a belt on one of these before so i aint a fecking clue lol.
if it was a simple change of belt then i cant see it being to hard.

only prob is its my mates and the cambelt broke so i didnt have a chance to get the old tipex out.

mart360

in that case you need to retime the top end along with the bottom end.

you need to get number one piston to tdc, and then retime the cams from there.. although you may need to remove the head to prevent contact... although you could just drop the crank down when a contact spot is felt, untill you find the right positions.. a bit crude,


its prolly best to remove the head, i doubtr you would have got away with not bending valves

Mart

34srm

get a grip, pugs dont time up at tdc, all pistons are inline half way down the bore for timing marks to aline

mark28

see you learn something new everyday

zoney-WRX

easy way round this is to set the timming by the old belt (unless its snapped) that way you cant go wrong

mark28

the engine is a later version of the wi16 lump as this one has the ajustable cam pullys

right then just got up to my works to have a play......

still no joy as when the crank pin is in then 2-3 are up!! but there is no where else the pin can go and you are all telling me that the pistons should be on level par when the pin is in

yes the cambelt did snap

mark28

would you like to explain to me then when the pin is in the crank 2&3 are at tdc

johnnyroper

if belt has snapped it will probably done some damage best thing to do in this case is take cam cover off rotate cams so no 1 and 4 cylinders inlet and exhaust valves are all fully closed i.e the back of cams are on top of valve buckets and lobes point up
then turn crank until pistons on 1&4 are at tdc put belt on and it will not be that far out should be good enough to see if it will run

in answer to your question about 2&3 at tdc with crank locked if what everyone says is correct about they should be half way down i would say that you are in the wrong hole in flywheel maybe had an aftermarket flywheel fitted that has been drilled wrong?

Normski

It can't be in the right place, because it would be impossible to rotate the camshafts to get them into their correct positions if the head had been taken off and replaced etc.

Do you have the crankshaft pulley off. As this has a locating dowel which may not be there, allowing the pulley to be put on in the wrong position.

mark28

all fine now and she is up and running

ok so the problem was with the bottom pully, some how it must of turn on its self. so the center section was in one place (correct place) and the outer part (ring section) was in the wrong place!! this making the timing impossible.

anyway after a a hour or two of messing around with it i got it sorted. i did this by putting the cam timing pins in and getting piston 1 one at TDC, then i turned the crank back 90degrees BTDC

just like to thank you all for your help

mark