crxaddikt

car is 90 crx si with zc dohc motor, timing belt snapped couple weeks ago,


before putting the new timing belt on, it said you need to set pistson #1 so its at TDC (top dead center), and line up the 2 cam gears so the "UP" marks point up,


my question is : if i were turning the crankshaft pulley around counter-clockwise, manually using a wrench, should the 2 cam gears be turning at the same time as when i'm turning the crankshaft pulley around ? (with no timing belt on the engine, since it snapped) ????


cause when i was turning the crank pulley around and round, the cam gears did'nt move at all ?, does the timing belt work to drive and turn the cam gears also ?


unless i did'nt give it a chance, not turning the crank enough rotatations for me to be able to see any movement out of the cam gears ?, (like if it it takes way more number of rotations to see cam gears doing any rotation) ?




any info to answer would be cool,

manicmechanic

the tbelt is what drives the cam gears. i belive that motor is an interference motor. so if the tbelt snap you might have bent valves. put the belt on and do a compression test. that will tell you if you have bent valves.

beansandrice

It might be a good idea to have an experienced mechanic help you out. Even if you pay for him to teach you.

I figure if you didn't even bother to search "how to change b18 timing belt" on google than it might be out of your realm.

jdmboyef9

If you had a timing belt snap then you have bent valves, possible damaged head and pistons. Any indication that the cam moves with the crank without a timing belt means guarenteed you have serious problems

Spug

If the cam shafts/cam gears turned without a timing belt...............then there would be no point in the timing belt.

Just sayin.

24TEN

iTrader: (2)

If you were riding a bike and the chain came off, do you think the rear wheel would still spin if you pedaled with no chain?

I am completely shocked that you couldn't figure that out just by looking at a diagram but I guess we all have to learn some how.

driftin90

I'm surprised you didn't hear a clicking noise. Every time you turn the crack, the more chance you have to do more damage. Just pull the head off. I can just tell you, you bent valves or did damage. Don't waste your time just putting on a belt.

crxaddikt

thanks for answering,

the first thing i thought was that the timing belt probably turned the cam gears around, like a bike chain etc..., but i did'nt know for sure, and it could of been that the camshafts turned the cam gears from inside or something? i did'nt know for sure, so thats why i asked to just confirm, i know it seems like common sense, but i don't know much about the cam gears & timing belt,

thats why i was having a mechanic friend of mine do the timing belt,

all i was doing was some of the first couple of steps, so i could get it started for him, so he could jump right into it and finish the whole thing quicker, like i got the wheel off and jacked up, alt belt and a/c belt & pulley off, motor mount off, valve cover off, and then the next step was setting to TDC and lining cam gears before starting to put the belt on,

thanks for the replies, at least i know for sure that the timing belt turns the cam gears, and thats why the cam gears were'nt turning, having no timing belt on.



it says in the steps, that before putting the timing belt on, you need to set to TDC and line the marks on the cam gears up, but since there is'nt a belt on it to be able to turn the cam gears to line them up, is it just ok to do that part after the t-belt is already on ? or do the cam gears supposed to be lined up along with TDC on the crank pulley before the t-belt goes on ???


also, not sure if it matters or not or if its an indication of any damage in the valves or not?, but the position of both of the cam gear sprockets are each different, like one on the left (facing gears from drivers side fender), has the "UP" arrow pointing at 10 o'clock position, and the one on the right has the "UP" mark arrow pointing around 2pm or something ????, is that normal to not be "in sync" with each other ????

or do they eventually start to line up if you start turning crank around, where both of the "UP" mark arrow start to come back to the same place, where they are both pointing in the same direction at the same time ???

skill178

I snapped a timing belt doin about 60 and all I did was put a new belt on... Call me lucky if you want but after doing a comp test I'm glad to say I didn't hit a valve... Don't pull the head unless your sure you did...

24TEN

iTrader: (2)

They spin in the same direction so the UP mark should be clocked together or at least very close.

Make a mental note of this:

When removing the timing belt, make sure everything is at TDC first. If it's not, you're just taking a chance that you'll be able to align everything again without bending a valve.

Now in your case, it was beyond your control and the timing belt snapped while driving. If I were you I would remove the camshafts entirely before spinning anything. This will guarantee that you won't bend any valves since they will all be in the closed position with nothing actuating them...this is of course assuming you haven't already bent them when you spun the crank by hand before with no timing belt or when the belt initially snapped. Once the crankshaft is at TDC, install the camshafts with the UP indicators as close to up as possible. The camshafts are at TDC when you see the two inner hash marks on the cam gear pointing at eachother, not level with the head.