My timing belt broke: How do I find TDC?
03-19-2010, 08:02 PM
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My timing belt broke: How do I find TDC?
My timing belt broke, on my 94ls 5spd integra. since the belt is not attached to the cam gears or the crankshaft pulley, how do you determine tdc? Please any help will be greatly appreciated, I have never replaced a timing belt with it being gone, usually you set the crank pulley at TDC loosen the timing belt tensioner and it's pretty straight forward from there, BUT HOW DO YOU DO IT WHEN THE TIMING BELT IS BROKE?
03-19-2010, 08:31 PM
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Re: Help HONDA TECH
The crank pulley has a white mark off by itself. This is TDC. And then the cam gears have marks on them that line up to each other and to the head. But you can't rotate them independently too far or you can cause damage.
Hondas are built to tight tolerances ("interference"), so like got00rice said, if you broke your timing belt, chances are very high that your pistons hit the valves.
Hondas are built to tight tolerances ("interference"), so like got00rice said, if you broke your timing belt, chances are very high that your pistons hit the valves.
03-20-2010, 09:42 AM
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Re: Help HONDA TECH
Thanks for the input,.
So if I set the pulley at TDC, and align the cam gears I should be ready to go? One of the cam gears is aligned, the other is off, how do I match them up again without any damage?
THanks again!
So if I set the pulley at TDC, and align the cam gears I should be ready to go? One of the cam gears is aligned, the other is off, how do I match them up again without any damage?
THanks again!
03-20-2010, 01:22 PM
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03-20-2010, 08:37 PM
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Re: I didn't read the rules but my timing belt broke
I read the rules however, the faq and tech section didn't cover, how you align the cam gears without the timing belt installed.
03-20-2010, 09:13 PM
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Re: I didn't read the rules but my timing belt broke
I would pull the head from the block and check for damage. Cause it sounds like there is from what you are saying. And for some reason there is no damage, you can easily align the cam gears up for TDC with the head pulled. Thats what I would do.
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03-21-2010, 06:24 AM
#8
Re: I didn't read the rules but my timing belt broke
You broke the rules by giving your post a vague title like 'I need help.' That's why nsxtasy posted the link to that topic (not the general rules topic).
Regarding the cam gears, you've already been told that they can be aligned according to the marks on the gears. There is one painted tooth on each gear. If those teeth face one another, the cam gears are at TDC. Failing that, you can stick a 5 mm punch or allen wrench through a hole at the top of each cam, through holes in the cam holder plates. If the cam is at TDC, the hole in the cam will line up with the hole in the plate. You need to take the VC off to do this.
But it doesn't even matter if you get the timing set if you've bent a valve. There's a very high probability that your valve and piston made contact when the timing belt broke. Unless you know that hasn't happened, you should pull the head and inspect the valves.
Regarding the cam gears, you've already been told that they can be aligned according to the marks on the gears. There is one painted tooth on each gear. If those teeth face one another, the cam gears are at TDC. Failing that, you can stick a 5 mm punch or allen wrench through a hole at the top of each cam, through holes in the cam holder plates. If the cam is at TDC, the hole in the cam will line up with the hole in the plate. You need to take the VC off to do this.
But it doesn't even matter if you get the timing set if you've bent a valve. There's a very high probability that your valve and piston made contact when the timing belt broke. Unless you know that hasn't happened, you should pull the head and inspect the valves.
03-21-2010, 11:44 AM
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Re: I didn't read the rules but my timing belt broke
You broke the rules by giving your post a vague title like 'I need help.' That's why nsxtasy posted the link to that topic (not the general rules topic).
Regarding the cam gears, you've already been told that they can be aligned according to the marks on the gears. There is one painted tooth on each gear. If those teeth face one another, the cam gears are at TDC. Failing that, you can stick a 5 mm punch or allen wrench through a hole at the top of each cam, through holes in the cam holder plates. If the cam is at TDC, the hole in the cam will line up with the hole in the plate. You need to take the VC off to do this.
But it doesn't even matter if you get the timing set if you've bent a valve. There's a very high probability that your valve and piston made contact when the timing belt broke. Unless you know that hasn't happened, you should pull the head and inspect the valves.
Regarding the cam gears, you've already been told that they can be aligned according to the marks on the gears. There is one painted tooth on each gear. If those teeth face one another, the cam gears are at TDC. Failing that, you can stick a 5 mm punch or allen wrench through a hole at the top of each cam, through holes in the cam holder plates. If the cam is at TDC, the hole in the cam will line up with the hole in the plate. You need to take the VC off to do this.
But it doesn't even matter if you get the timing set if you've bent a valve. There's a very high probability that your valve and piston made contact when the timing belt broke. Unless you know that hasn't happened, you should pull the head and inspect the valves.
03-21-2010, 01:22 PM
#11
Re: My timing belt broke: How do I find TDC?
Bent valves will cause compression loss, so a bad reading indicates possible bent valves.
@ gravity:
If the timing is not close to correct, it is not safe to manually turn either the crank or the camshafts, because you can actually bend the valves hand-cranking. Unless both the cams and crank are within a couple teeth of being correct, you should pull the cams, set the crank at TDC, then re-install the cams at TDC.
@ gravity:
If the timing is not close to correct, it is not safe to manually turn either the crank or the camshafts, because you can actually bend the valves hand-cranking. Unless both the cams and crank are within a couple teeth of being correct, you should pull the cams, set the crank at TDC, then re-install the cams at TDC.
03-21-2010, 01:37 PM
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Re: I didn't read the rules but my timing belt broke
You broke the rules by giving your post a vague title like 'I need help.' That's why nsxtasy posted the link to that topic (not the general rules topic).
Regarding the cam gears, you've already been told that they can be aligned according to the marks on the gears. There is one painted tooth on each gear. If those teeth face one another, the cam gears are at TDC. Failing that, you can stick a 5 mm punch or allen wrench through a hole at the top of each cam, through holes in the cam holder plates. If the cam is at TDC, the hole in the cam will line up with the hole in the plate. You need to take the VC off to do this.
But it doesn't even matter if you get the timing set if you've bent a valve. There's a very high probability that your valve and piston made contact when the timing belt broke. Unless you know that hasn't happened, you should pull the head and inspect the valves.
Regarding the cam gears, you've already been told that they can be aligned according to the marks on the gears. There is one painted tooth on each gear. If those teeth face one another, the cam gears are at TDC. Failing that, you can stick a 5 mm punch or allen wrench through a hole at the top of each cam, through holes in the cam holder plates. If the cam is at TDC, the hole in the cam will line up with the hole in the plate. You need to take the VC off to do this.
But it doesn't even matter if you get the timing set if you've bent a valve. There's a very high probability that your valve and piston made contact when the timing belt broke. Unless you know that hasn't happened, you should pull the head and inspect the valves.
03-21-2010, 01:44 PM
#14
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Re: My timing belt broke: How do I find TDC?
Bent valves will cause compression loss, so a bad reading indicates possible bent valves.
@ gravity:
If the timing is not close to correct, it is not safe to manually turn either the crank or the camshafts, because you can actually bend the valves hand-cranking. Unless both the cams and crank are within a couple teeth of being correct, you should pull the cams, set the crank at TDC, then re-install the cams at TDC.
@ gravity:
If the timing is not close to correct, it is not safe to manually turn either the crank or the camshafts, because you can actually bend the valves hand-cranking. Unless both the cams and crank are within a couple teeth of being correct, you should pull the cams, set the crank at TDC, then re-install the cams at TDC.
still much much easier than removing cams.
03-21-2010, 01:51 PM
#15
Re: My timing belt broke: How do I find TDC?
I'd be scared to do it that way because I'd worry that I couldn't tell a difference between the resistance of a valvespring from that of a valve about to bend. Pulling the cams only takes 15 or 20 min, so that's what I'd do, but it's nice to know there's another method.
03-21-2010, 04:38 PM
#16
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Re: My timing belt broke: How do I find TDC?
oh it's really easy to tell the difference. when you push the valve into the piston it's a solid stop. you actually have to hit it pretty hard to bend.. the worst part about pulling cams is re setting the lash
03-23-2010, 01:09 PM
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Re: My timing belt broke: How do I find TDC?
so I can turn the cam gear to TDC as long as I turn the crank pulley as well, to keep the valve from hitting the piston?
03-23-2010, 02:23 PM
#20
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Re: My timing belt broke: How do I find TDC?
this is the direction the engine is designed to move, BUT are you really that far off? when you have the TDC crank mark up what do the cam dots look like? you should be able to just move the cams a touch and install the belt. oh and make sure you follow procedure installing the belt !
you never did tell us how far out of wack the relationship between crank and cam is
you never did tell us how far out of wack the relationship between crank and cam is
03-23-2010, 07:33 PM
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Re: My timing belt broke: How do I find TDC?
this is the direction the engine is designed to move, BUT are you really that far off? when you have the TDC crank mark up what do the cam dots look like? you should be able to just move the cams a touch and install the belt. oh and make sure you follow procedure installing the belt !
you never did tell us how far out of wack the relationship between crank and cam is
you never did tell us how far out of wack the relationship between crank and cam is
The crank is at tdc, the intake cam is tdc the exhaust cam is off tdc by about four teeth. When I turn exh clock wise, it wants to snap back? I have yet to attempt counter clockwise in fear of damaging something?
I really appreciate all the input! Thanks for helping a rookie out!
03-23-2010, 09:07 PM
#22
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Re: My timing belt broke: How do I find TDC?
that's the valvesprings you're feeling. twist that bitch till it lines up. obviously leave the intake alone. hold on to the exhaust cam tight when you feel it starting to snap, just move it around. if you feel a positive stop and it's obvious if there is one then you move the crank enough to allow the valves to pass. being off about 4 teeth isn;t ****. just line the marks up and put on a new belt.
03-24-2010, 11:19 AM
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Re: My timing belt broke: How do I find TDC?
that's the valvesprings you're feeling. twist that bitch till it lines up. obviously leave the intake alone. hold on to the exhaust cam tight when you feel it starting to snap, just move it around. if you feel a positive stop and it's obvious if there is one then you move the crank enough to allow the valves to pass. being off about 4 teeth isn;t ****. just line the marks up and put on a new belt.
Awesome thanks alot bro! I also just got my "special" honda crank pulley tool in the mail, so I'm ready to go!!
I will update once I get it back together and on the streets.
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