help timing belt change?

[oneslow240se]

I've read thru the FSM on chaning the belt, currently i have the crank at TDC cyl #1 is at top most position and i noticed that the intake and exhaust cam gears did not line up with the timing marks on the rear cover... i have not change my belt yet but it seems as if it had been change before since there are white paint marks on the cover/cas and crank.. so i don't knoe what gives if im at TDC shouldnt the dots on the cam gears line up with the marks on the cover and the dotted and solid line on the belt didn't actually line up with any marks. so i'm not sure what to do.

all the belts (A/C, P/S, ALT) that were remove are PITWORKS brand not sure if thats stock manufacture belts or what ..

1. Should the dot on the cam gears be lined up with the alignment marks at TDC?2. I'm replacing it with the greddy belt. The dotted and solid line are marks to assist in the install? if so what should they be lined up too?
Modified by oneslow240se at 8:10 PM 10/7/2007

[themadscientist]

I never worry about marks on the belt, just square up the gears to the marks and keep all slack on the tensioner side.

[eh?]

Worry about the marks on the crank sprocket and cam gears lining up with their respective alignment marks.When all three are aligned the engine is #1 at TDC.You don't have to align the belt marks with the cam/sprocket marks but supposedly makes it easier.

[oneslow240se]

So as long as the crank is at TDC and cyl #1 is at top position, i can remove the belt and rotate the exhaust and intake cams individualy so that the dots on the cam gears match with the alignment marks on the back cover?? . It just thru me off when i checked the crank sprocket at TDC that the cam gears did not line up with the alignment marks which worried me

[themadscientist]

caution is never a bad idea, bent valves suck!

[oneslow240se]

thanks guys..... i couldn't get a clear picture of the alignment points off the FSM

[eh?]

Is this out of a running engine?

The marks should always align at a certain point. If they don't keep rotating. The Rb's are interference engine, you can't just rotate the cams to align them.

[S13 240SX]

thanks guys..... i couldn't get a clear picture of the alignment points off the FSM

if you can't find any better pictures give me intill tomorrow morning and i'll post them for you.

i know a few forums that have them but i dont have time to go on them now and post the links..

so i'll check back up with you tomorrow morning if you still need to find and see some actual better photos.

[oneslow240se]

the engine is still sitting on the pallet. I don't knoe the history of the engine. I finally got the time to mess with it today. so im in the process of changing out the water pump, timing belt and tensioners. Thats why i was asking about the alignment of the timing marks on the cam gears. So before i take the old timing belt off i wanted to line up the crank sprocket to TDC. which the cam gear marks did not line up but i could tell it has been change before because of the paint marks on the belt and cams/crank

So i should keep turning the crank to TDC untill i get the cams to line up? I don't knoe anything other then reading the fsm about the timing on the RB's but to my understanding if the crank is at TDC and the cyl #1 is at top position the cams should be lined up. so i don't knoe what the deal is with the one thats on the motor now

I can't take the belt of and rotate the cams to line up with the marks then put on the belt?

[themadscientist]

that's what I docrank gear mark at about 5 oclockexhuast gear mark at 3 oclockintake gear mark at 9 oclock

as long as those marks are lined up you are fine. The teeth will not line up perfect, rotate the sprockets clockwise to engage the teeth, all slack must be on the tensioner side, the right side should be taut.

[oneslow240se]

.. crank is lined up, cams are not. Am i suppose to keep turning the crank to TDC untill the cams line up with the marks? Is it safe to remove the timing belt with the crank at TDC and turn the cams till its lined up intake at 9 and exhaust at 3 oclock?

note: i have not yet took the old belt off i was just trying to line everything up before i remove the old belt ..

[themadscientist]

that would be the best thing

[oneslow240se]

thanks for the responses the FSM doesnt answer questions just trying to avoid having to do this twice especially after its in the car


Modified by oneslow240se at 1:25 AM 10/8/2007

[sxracerb25]

remember the crank spins twice for every one spin of each cam so you're probably on the exhaust stroke instead of compression...turn it another turn and they'll probably line up

[oneslow240se]

thanks for all your help...everything lines up now. you guys were right, the crank had to make 2 rotations for the cams to line up..

i was suprise to see how clean the ports to the water pump was, there was no old fluid build up... new waterpump, tensioners and greddy belt on and DONE!

again thanks for the help
Modified by oneslow240se at 7:09 PM 10/8/2007

[S13 240SX]

cool glad to see you got it going and good to hear it took 2 rotations to line up.. lucky

mine don't and i went around 20 times and my exhuat cam is always off 1 kinda mad.

[themadscientist]

Your belt is one tooth off then.

[S13 240SX]

how is that? when i installed it... i even installed it to line up the timing belt white slotted and dotted lines.

[mello88]

it only matters during install don't worry about the timing marks on the belt ever lining up again. Those marks are only there so that when you put it to TDC, the cam gears line up to marks on the upper timing back plate, and the crank pulley lines up to the TDC mark on the oil pump. Now you use the lines on the belt when you install to make sure it's not off a tooth.... But after you get the belt on, those lines don't matter, don't try to get them to line up again just reset the engine to TDC compression stroke if you need to pull the belt. GL

[RBKIDD]

when the engine is at tdc the first 2 lobes on the cams should be facing away from each other

[themadscientist]

Those lines mean nothing to me, I slap belts on to the marks on the engine. If at TDC on #1 compression you are one tooth off you are 1 tooth off regardless of the little lines on the belt. How off? Is it one entire tooth or kinda one tooth? Agressive decking of the head or block, other than stock head gasket thickness etc can throw the timing out of spec. I have heard some guys purposefully advancing their cams by clocking the cams one tooth ahead on some engines. Sounds like bad juju to me though.

[S13 240SX]

Those lines mean nothing to me, I slap belts on to the marks on the engine. If at TDC on #1 compression you are one tooth off you are 1 tooth off regardless of the little lines on the belt. How off? Is it one entire tooth or kinda one tooth? Agressive decking of the head or block, other than stock head gasket thickness etc can throw the timing out of spec. I have heard some guys purposefully advancing their cams by clocking the cams one tooth ahead on some engines. Sounds like bad juju to me though.

i am one full tooth off..

but listen to this.

i replaced the belt, i spun engine lots of times to make sure they would still line up and they did.

so i started my engnie up. took a while to start, and when it did start it idle rough and hard it was crazy. so i shut it off and checked my timing marks again

and when i checked and spun engine by hand again the exhaust was off by 1 full one.

but i dont get why cuz i made sure after i installed the belt they were lined up and i spun it lots of times before i starting to make to make sure all marks line up.

so what i don't get is why its off again?

everything is stock on the engine if you asked me i think you did.

[themadscientist]

That is strange. Is it advanced (mark on pulley above mark on backplate) or retarded (mark on pulley below mark on backplate)? That is too much to be belt stretch, I don't know what to tell you. You will need to go back in there and correct it though.

[oneslow240se]

Oyeah this was something i over looked.. even thoe i had everything lined up. I noticed i had way too much slack on the belt (tensioner side). The spring seemed kinda loose to me with very little tension. I checked the FSM again and noticed in the picture the finger was holding the spring. so i took the tensioner back off and wined up the spring then put it back in. The belt is much tighter but have little slack. Im thinking you may have over looked something during the install

Modified by oneslow240se at 1:02 AM 10/10/2007
Modified by oneslow240se at 1:03 AM 10/10/2007

[themadscientist]

you take an allen wrench, a 6mm I think and wind the tensioner back and lock the nut down. Install the belt. You will need to turn the cam sprockets a tiny bit clockwise to engage the belt teeth. It should be taut on the right side all slack on the left, Loosen the nut and allow the tensioner to swing out an tighten up the belt. I give the tensioner a little extra with the wrench and let it settle back and lock the nut down.

[S13 240SX]

That is strange. Is it advanced (mark on pulley above mark on backplate) or retarded (mark on pulley below mark on backplate)? That is too much to be belt stretch, I don't know what to tell you. You will need to go back in there and correct it though.

i dont know what you mean by that i only went by the 3 marks.

2 cam dots, and 1 crack sprocket that lines up oilpump housing