Top Dead Centre!

[Coops]

Can anyone give me an idiots guide to the rambling rubbish in my haynes manual about cambelt n head removal? its goes on about top dead centre (TDC) and lining up the marks on the crankshaft and camshaft sprockets and that number 1 piston at flywheel end must be TDC on the exhuast stroke or something. do i need to worry bout this when am takin it apart (cuz thats monday nights job!!)or only when i refit the cambelt n head to get the timing right??

any help wud be much appreciated!!

Coops

[Plattsy]

tdc is when the piston is at the very top of its stroke where as bdc is when its at the very bottom of its stroke.

i cant see it being an issue when you take it apart but essential when you put it back together....could be wrong tho. im certain about it being right when you put it together jus not when u take it apart

[richy]

if u buy a cambelt from renault it comes with the timing marks on the belt, dont know about non-gen belts tho, theres a mark on each camshaft pulley which also line up with the rocker cover, which when u take the cam pulley cover off u will see! and once u take the pulley off the crank which the aux belt runs on u will see a dot which the other mark lines up to!
basicly u want the engine turned around to TDC if u have a TDC pin or can borrow one that fits the bolt u need to remove to fit it is to the right and down from the oil filter, its in the bottom right hand corner if u take the radiator out u can see it clearly, lock it up in there(it locks both ways) then take all the covers etc needed off, u will quite clearly(should) see the 3 timing marks 1 on each pulley ie 2 on camshafts and 1 on crank pulley

[BenR]

if you have your gearbox on, there is a making on the flywheel, line it up with the zero degree marking on the gearbox.

[VIPERONE]

the flywheel can only go on one way... there is a star shap bolt on back of block, remove this and put in a 6mm allen key to lock the crank at tdc.. alternatively just move every piston halfway down the bores.

place gasket on
put head on, tighten head bolts in correct order
line the 2 cam pullies as close to 12 oclock position as you can, one will be slightly off... which isnt a problem.. look at the crank pulley, there is a dot,...line the belt dot with the crank pully then alighn the 2 white lines on the belt with the cam pullies,place belt on.. you might need to use a spanner to ease one of the pullies to the 12oclock position.. once the belt is on tension it ... ensuring that there is 1.5-2 mm of play on the longest run of the cam belt..easy way is to test tension is to attempt to twist the belt 90 degrees,,, when you can just do it its tensioned corectly(or close enough)

check everything 3-4 times..that all lines and marks are correct...otherwise catastrophic failiure may occur

[Coops]

if u buy a cambelt from renault it comes with the timing marks on the belt, dont know about non-gen belts tho, theres a mark on each camshaft pulley which also line up with the rocker cover, which when u take the cam pulley cover off u will see! and once u take the pulley off the crank which the aux belt runs on u will see a dot which the other mark lines up to!
basicly u want the engine turned around to TDC if u have a TDC pin or can borrow one that fits the bolt u need to remove to fit it is to the right and down from the oil filter, its in the bottom right hand corner if u take the radiator out u can see it clearly, lock it up in there(it locks both ways) then take all the covers etc needed off, u will quite clearly(should) see the 3 timing marks 1 on each pulley ie 2 on camshafts and 1 on crank pulley

so i stick the pin in that hole u on bout, lock it the turn crank till engine locks to TDC? that right? am just kinda nervous bout it all cuz never done this before!!!haha!

[Coops]

if you have your gearbox on, there is a making on the flywheel, line it up with the zero degree marking on the gearbox.

am leavin the engine in, so how do i locate the flywheel? where the heck is it? am not up on al this yet, still learnin!!!

[VIPERONE]

its hidden by the gearbox

[Coops]

so flywheel end is gearbox end?!!! no danger, i can work it from that n the haynes manual no worries i hope. oh n me mate who runs a garage of course!!! (he wudnt take on the job for fear of blockin up his productivity for ages with me valver!!!kinda beginning to see where he was comin from!!lol!)

[richy]

when i say it locks the crank both ways i mean once the TDC pin is in and located the crank cannot turn either clockwise or anti-clockwise, as some engines for example K4M etc have a free floating crank and only locks clockwise :wink: , but dont worry these(f7p/f7r) are easy to do, u need to turn the engine over to TDC on number 1 or 4 pistons, dont matter which they both rise together, get the pin and and check its locks both directions, if your fitting the head on after just make sure both camshafts have the timing marks near the top, just stops them contacting the pistons when u have them 180 out!! you can see the white marks on the pulleys(verniers in this case) and the 2 white lines on the belt, the crank pulley as said before has a dot/mark there not always painted but is a identation etc

http://i4.photobucket.com/albums/y110/c20rfs/P2130024.jpg

[Coops]

cheers richy!top lad for that, big help!

am lookin at the course of the cam belt on that pic n thinkin tryin to change the idler n tensioner and put the belt back with the engine in the car may be a bit difficult? that right or wrong?

Coops