kevinz Posted October 9, 2008 Report Share Posted October 9, 2008 OK, so I just got a 93 Lumina Z34 last week. Since then, I've been researching the engine in the car because I love working on cars and would like to know as much about the engine as possible. However, I seem to have encountered a brain fart when reading the timing belt change tech article on 60degreev6.com. Here's what I'm talking about: 1) Why do the cam sprockets need removed? It makes no sense to me as to why, so if someone can explain it to me, I'd appreciate it. 2) It says in the article to rotate the crank until the rear cam flats are flats down. How in the hell are the cams gonna turn when there ain't no belt on them, and further, how in the heck would you keep the cams from moving as you put the belt on without using a cam hold down tool, as you just rotated the cam flats down? Sorry if these sound dumb, but I am really, honestly confused here. Maybe someone here that has done this before can help me understand. BTW, my car doesn't need a timing belt right now, it was just done by previous owner. Quote Link to comment Share on other sites More sharing options...
trbo31 Posted October 9, 2008 Report Share Posted October 9, 2008 the books make it more complex than it needs to be.-you only need to do that if you need to correct the timing or change it. The sprokets are not keyed but they should have paint marks from the factory that should point twords each other when the intermedete pully mark is on. the flats on the cams need to be held down with a tool then you can lossen the pullys and set the belt. Its not that hard to change a belt on these you don't have to do it the hard way just use the paint marks. I've changed probebly 20 timing belts on the LQ1.(I used to be the head of -34 Special- a all 3.4 LQ1 car club in Grand rapids michigan until most of use moved to other cars) Quote Link to comment Share on other sites More sharing options...
IRONDOG442 Posted October 9, 2008 Report Share Posted October 9, 2008 WFC? Quote Link to comment Share on other sites More sharing options...
kevinz Posted October 9, 2008 Author Report Share Posted October 9, 2008 thanks for the replies...what does "WFC" mean? Maybe this is something I need to watch or help someone do to understand how it all goes work... Quote Link to comment Share on other sites More sharing options...
GP1138 Posted October 10, 2008 Report Share Posted October 10, 2008 The cam sprockets need to be loosened at least so the timing can be set properly. The idea behind this is that the sprockets get turned on the cams and need to be reset, and using the correct way, you need to have one bank's cams loosened so you can rotate the engine 180*. This allows the cams to be set properly. One bank must be 180* reverse from the other. Read on: Once you get the engine torn down, it all becomes clear. TDC is set when you have the crank mark lined up with the mark on the block and you rotate the engine once. The front and rear banks need to be 180* from each other. So if you have the front paint marks lined up, you need to have the rear bank's paint marks 180* reversed. Count teeth and you should be able to figure out if you have this straight. I used the paint marks myself, only clamped down the front bank, and set the rear bank the opposite way using the valve pressure to hold the cams in place. This worked just fine, my car runs great. If for some reason yours doesn't using my method... it is a half-assed way to do it, but if your cam sprockets have not rotated on the cams, you should be fine. Quote Link to comment Share on other sites More sharing options...
White93z34 Posted October 10, 2008 Report Share Posted October 10, 2008 disclaimer: anything I suggest is more or less "by the books" I am well aware that there are other ways of doing it. however following the FSM has served me well on this job 1) Why do the cam sprockets need removed? It makes no sense to me as to why, so if someone can explain it to me, I'd appreciate it. they need to be removed so they can spin freely on the cam shafts so you can set the timing correctly. 2) It says in the article to rotate the crank until the rear cam flats are flats down. How in the hell are the cams gonna turn when there ain't no belt on them, and further, how in the heck would you keep the cams from moving as you put the belt on without using a cam hold down tool, as you just rotated the cam flats down? Initially you have the belt removed and you will set all the cams the same way with the cam flats up, and held down with the the cam hold down tools. you will install the belt like that, and put tension on it then once that is set you will remove the REAR cam hold down tool and rotate the engine 180 degrees that should put the rear cam flats down. and the front ones will stay in place because you have yet to re tighten the front cam cogs. then you will tighten down the front cogs, and the timing is set and honestly I would never trust the timing paint marks on the cogs. BTW, my car doesn't need a timing belt right now, it was just done by previous owner. Quote Link to comment Share on other sites More sharing options...
kevinz Posted October 10, 2008 Author Report Share Posted October 10, 2008 disclaimer: anything I suggest is more or less "by the books" I am well aware that there are other ways of doing it. however following the FSM has served me well on this job 1) Why do the cam sprockets need removed? It makes no sense to me as to why, so if someone can explain it to me, I'd appreciate it. they need to be removed so they can spin freely on the cam shafts so you can set the timing correctly. 2) It says in the article to rotate the crank until the rear cam flats are flats down. How in the hell are the cams gonna turn when there ain't no belt on them, and further, how in the heck would you keep the cams from moving as you put the belt on without using a cam hold down tool, as you just rotated the cam flats down? Initially you have the belt removed and you will set all the cams the same way with the cam flats up, and held down with the the cam hold down tools. you will install the belt like that, and put tension on it then once that is set you will remove the REAR cam hold down tool and rotate the engine 180 degrees that should put the rear cam flats down. and the front ones will stay in place because you have yet to re tighten the front cam cogs. then you will tighten down the front cogs, and the timing is set and honestly I would never trust the timing paint marks on the cogs. BTW, my car doesn't need a timing belt right now, it was just done by previous owner. AHHHHH now it has become much, much clearer...thanks! Quote Link to comment Share on other sites More sharing options...
spiderw31 Posted October 10, 2008 Report Share Posted October 10, 2008 ...remove the REAR cam hold down tool and rotate the engine 180 degrees that should put the rear cam flats down. Just for clarification, wouldn't the engine need to be rotated 360*? That would make the cams rotate 180* which is what you'd be after, right? Quote Link to comment Share on other sites More sharing options...
White93z34 Posted October 11, 2008 Report Share Posted October 11, 2008 yes, thats what I meant to say. sorry! yes, rotate the engine 360 till the timing mark is lined up again! Quote Link to comment Share on other sites More sharing options...
spiderw31 Posted October 11, 2008 Report Share Posted October 11, 2008 Ok cool... just wanted to make sure, as I'm gonna be getting my car put back together soon hopefully Quote Link to comment Share on other sites More sharing options...
White93z34 Posted October 11, 2008 Report Share Posted October 11, 2008 ok, just re-read that. a good bit of my info is wrong. i'm going to correct and repost it after checking the books Quote Link to comment Share on other sites More sharing options...
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