Is this normal? (timing belt marks)

[dhen]

Ok, so I think my timing may have been off. I was using a timing belt with no marks on it. I installed a Good Year timing belt part number 40137 and lined up the marks. I spun the engine around a few times using the starter and now the marks are off by two teeth. The harmonic balancer was still off, but I don't see why that would matter.

(I haven't been able to run it yet because I have a cracked manifold to deal with.)

Here's a picture:





Is this normal or is there something wrong?

[Buddyworm]

Can't speak to the belt markings, all of my belts have had them but I never use them. I would THINK that they should line up again at TDC after one complete cycle.

The reliable way to check is to start at TDC with everything lined up and do two full rotations of the crank (this means doing it by hand while feeling carefully for resistance, frankly using the starter sounds like a good way to bend a valve if you're unsure of the cam timing). If the cam gear markings line up with the back plate with the crank back at TDC you did it right.

[themadscientist]

I don't use the belt marks. If your reference marks on the cam gears and crank gear are 5x5 you are golden. You need to twist the exhuast cam a little bit clockwise past the mark to properly tension that side of the belt. Once it's engaged and taut it will line up. If you have had the head or block decked that can cause more timing change than you would suspect too.

[dhen]

Well, I turned it around manually a few times and the marks moved some more. I double checked the part number. I figured that this is just what happens and then I fired it up. I ran it for a minute or so and revved it a couple of times. I didn't notice anything weird.

So I guess this is normal. I still have to do a couple of things before I can drive it. Hopefully this was my problem with boost.

Keeping my fingers crossed...

[dhen]

Update: I just checked and the CA timing belt has 151 teeth. Since that's an odd number, there's my explanation...

[biosehnsucht]

Weird. I lined mine up using the markings, but maybe it's a case of if you have it all lined up then it'll be correct, but you can also get it correct the "hard" way, and either way it'll go "off" over time.

[TheMAN]

well you did use an OEM nissan belt bio... the dude isn't

[mr_ca18det]

Once you spin it over it won't line up with the belt again. If the marks are good after you spin it you'll know if its off atooth itwon't be just a hair off. You need to give us a picture with the cams and with the crank lined up with the mark on the bottom end.

[dhen]

Once you spin it over it won't line up with the belt again. If the marks are good after you spin it you'll know if its off atooth itwon't be just a hair off. You need to give us a picture with the cams and with the crank lined up with the mark on the bottom end.

They were all lined up when I put the belt on. I don't have a picture of that, but I was careful to do it right.

Thanks for confirming that it won't line up with the belt after you spin it.

Darian

[TheMAN]

spin it a couple of times and it'll line back up

[mr_ca18det]

This is true it may line back up eventually again but that could 10 20 times who knows but the main thing is the marks.

[dhen]

If you have had the head or block decked that can cause more timing change than you would suspect too.

This would mean that I need to advance or retard the timing? I'm guessing advance since the distance would be shorter.

[themadscientist]

I can't remember the rotation, I think since the tensioner is on the left as you look at it that means it rotates clockwise which means it would retard it slightly. The distance between the sprockets would be less which would let the cams rotate back counter clockwise just a bit and thus retard the timing.

[float_6969]

It's normal for the marks to be off after you rotate it. As you stated, there are an odd number of teeth, so it won't stay lined up. I figured it up once for s***&giggles to see how many rotations it took to get back to lined up and it was something rediculous.

If your 3 marks are lined up, then you're fine. I will say it's easy to get the exhaust cam off a tooth. Whenever I do it, I have the valve covers off, and I have 2 HUGE spring-type paper clips that I use to hold the belt in place on the cam gears.

[dhen]

I'm beginning to think that my engine trouble is a misadjusted timing belt, although I was careful. I read somewhere that when you tighten the tensioner, it should lock into place. There's nothing in the FSM about this. Is this true?

Darian

[mr_ca18det]

how i do it it is i get a pair of needle nose vise grips ready i set the tensioner all the way loose then tighten it so it stays. then i line the crank gear up then i start on the exhaust side and usually have to turn the cam slightly clock wise line it up just past the mark on the head. then clamp it just enough to hold the belt on with the vice grips. the tension of the springs should spring it perfectly lined up on that side then i move to the intake side you will have to turn it slightly counter clockwise and i slip the belt on by hand there is just enough room to do this then i tension the belt and all marks should line up almost perfectly. hope this helps. and the tension on the belt should be just snug too tight and it will make noise and maybe even eventually snap. And i had my block decked and head shaved and marks were almost dead on a tooth of either way is pretty noticeable.

[themadscientist]

Put a rag under the grip jaws to protect the belt, but otherwise a sound scheme. I've seen people use a zip tie for the same effect. I use my hands, but I'm all awesome and s***.

[dhen]

I've seen people use a zip tie for the same effect.

Don't knock zip ties! If it weren't for them and duct tape, I'd never get anything done.

Thanks for the input, guys.

Darian

[themadscientist]

Not knocking them. I made racing brake lines out of them. Figure that one out.

[biosehnsucht]

Hell, I used zip ties to hold my SS brake lines on, plus ziptied on some slit vacuum hose as protection against rubbing, when I changed my front brakes to "180SX" from USDM brakes, cause they didn't line up with the stock strut mount anymore..

[TheMAN]

brake lines are child's play.... you used zip ties to hold your engine block on your stand!

[roast]

Not knocking them. I made racing brake lines out of them. Figure that one out.

zipbraided rubber core brake lines! I bet you didn't even cut off the ends...

Did it improve pedal feel?

lol

[dhen]

OK, I just want to be 100% sure my timing is right. It was hard to see the marks in the space I had to work with, so I removed some stuff. Anyway, here's some pictures and please let me know.

Intake:



Exhaust:



Crank:



Thanks, Mr. CA, for telling me about going on the exhaust side first. Much easier than going the other way...

[themadscientist]

Not knocking them. I made racing brake lines out of them. Figure that one out.

zipbraided rubber core brake lines! I bet you didn't even cut off the ends...

Did it improve pedal feel?

lol

Of course I cut off the ends. Brake line whiskers are so ghetto! I R A Profshunel.
It actually did improve it, but nothing close to true braided lines.

[mr_ca18det]

Its the little details that help lol. But that looks good if you had it decked or the head shaved that would be why there not perfectly pointing to the marks.

[dhen]

Thanks for letting me know. It looks like my engine management system is the problem...

Darian

[mr_ca18det]

what engine management u run i have nistune and it works alright but i wish i would have went megasquirt.

[dhen]

what engine management u run i have nistune and it works alright but i wish i would have went megasquirt.

I have the HKS VPC piggyback system. I'm seriously considering Megasquirt as well. Why do you regret going Nistune?

[mr_ca18det]

Double post

[mr_ca18det]

Due to the ca ecu being older than the Sr its slower to respond to what's programmed in the maps. For example when i had my s15 turbo lets say i had my timing at like 30 before spool up and if you try to taper it down to say 16 when in full boost the computer cant adjust fast enough and your timing will drop down to like 8 degrees then when your in the higher load areas it stay in longer it will come back up to where it should. Does that make sense. But i'm not the only one with this problem its not the end of the world and its not a nistune problem its just a slower computer so fast adjustments arent possible. And megasquirt can control everything boost luanch control. I'm almost possitive ca ecu run a 128 bit system as opposed to the sr is 256 maybe. But if your running it stock or light mods nistune works its just fast spooling turbos dont work very well. There is ways to get rid of a lot of the timing drop just takes alot of messing with. But its super easy to use and is user friendly