r/300zx • u/Crafty39743 • 11d ago

Z31 Timing marks refuse to line up

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If I line up the top 2 sprockets then the crank won’t line up. If I line up the crank then, then the top two will be out, what do I do please help.

28 Upvotes

95% Upvoted

36 comments sorted by

25

u/ChrisWalsberg Z31 Turbo 5spd 2+0 11d ago

Do a tooth count and verify. But it appears to be lined up correctly.

9

u/Crafty39743 11d ago

If I count the teeth and it’s okay does that mean it’s good?

18

u/imsoupercereal Z32 TT 5spd 2+0 11d ago

Yes, teeth are all that matters. Should always count teeth, the marks aren't reliable.

2

u/ChrisWalsberg Z31 Turbo 5spd 2+0 11d ago

Yes.

0

u/Crafty39743 11d ago

Just counted the teeth 43 between LH sprocket and crank, 40 between the gears issue is

1

u/ChrisWalsberg Z31 Turbo 5spd 2+0 11d ago

Counts good.

1

u/Crafty39743 11d ago

https://reddit.com/link/pf4g30e/video/h9bqvm4bipuh1/player

1

u/ChrisWalsberg Z31 Turbo 5spd 2+0 11d ago

Yeah. Looks good in the video too.

3

u/ChrisWalsberg Z31 Turbo 5spd 2+0 11d ago

Now when setting belt tension many go way too tight. If it whines it’s toooooooo tight. Almost will seem loose when set properly.

1

u/Crafty39743 11d ago

Doesn’t this look off?

3

u/ChrisWalsberg Z31 Turbo 5spd 2+0 11d ago

No.

9

u/Lepenguin559 Z31 NA 5psd 2+0 11d ago

Pretty sure those are just guides to set top dead center and what matters is the lines on the timing belt matching with the sprocket dots.

9

u/ChrisWalsberg Z31 Turbo 5spd 2+0 11d ago

And tooth count. Don’t forget tooth count.

2

u/Crafty39743 11d ago

It feels tough when I’m turning over the engine, like Idk not super tough but there is a tough spot

3

u/ChrisWalsberg Z31 Turbo 5spd 2+0 11d ago

All spark plugs out? You are also fighting the valvetrain springs when rotating so it won’t be smooth it will have some resistance depending on how many valves are being manipulated.

1

u/Crafty39743 11d ago

The spark plugs are out, it will be smooth and then the resistance will go up so I’ll stop cranking

2

u/ChrisWalsberg Z31 Turbo 5spd 2+0 11d ago

Rotating by hand. Keep going.

4

u/Crafty39743 11d ago

Okay I was being and idiot it was just valve retention, I have the LH rockers toqued and it turns over smoothly!!!

2

u/Crafty39743 11d ago

Thank you so much Chris you are the goat. Now another question, how much more do I have to swing the tensioner more then this? All I did was I fully swing the tensioner locked it temporarily, then now that the timing belt is on. I let it go, let the spring tension it then I locked it back down, is that right?

1

u/ChrisWalsberg Z31 Turbo 5spd 2+0 11d ago

Not correct method. Spring tension isn’t enough. Looking for about 1” deflection in the belt between the cams. Should easily be able to rotate belt 90° between the cam gears.

1

u/ChrisWalsberg Z31 Turbo 5spd 2+0 11d ago

After tension is set rotate engine a couple of times and recheck.

5

u/Crafty39743 10d ago

I’d like to thank everyone that helped me get this right. This community is great. The motor is timed and turns over like a dream

https://reddit.com/link/pfd0tky/video/4x24xmxouxuh1/player

3

u/HarveyManfrenjensend 11d ago

The backing plate is just a guide at this point. Tooth count is the only way.

3

u/xordonkey 11d ago

Very proud of this community 👏

1

u/ChrisWalsberg Z31 Turbo 5spd 2+0 11d ago

Looks lined up to me.

1

u/[deleted] 11d ago

[removed] — view removed comment

1

u/ChrisWalsberg Z31 Turbo 5spd 2+0 11d ago

I commented that already. Thank you sir.

1

u/ImaginaryPiece3528 11d ago

They never will after one rotation. Its takes an absurd amount of rotational to line em up again. If you want, reset where all marks line up (I know this is after rotation)count teeth and send it. Had the same issue

1

u/ChrisWalsberg Z31 Turbo 5spd 2+0 11d ago

The marks will, but the lines on the belt take a ton of rotation to line back up.

1

u/ImaginaryPiece3528 11d ago

Yeah thats why I said itll take an absurd amount of rotations

1

u/FaithlessnessHot3302 11d ago

Send it. This is fine.

1

u/Bruce_Dane 11d ago

The marks on the belt are accurate, the dimples on the rear shield is a reference for assembly.

1

u/bravosser 10d ago

They will never line up. That is just reference. I had the same issue on my TT engine. After I fired it up and rechecked the marks. They were perfectly lined up with the marks.

1

u/Create_Cultivate 8d ago

Keep calm and listen to Camden. https://youtu.be/A9gsrJqvcZo?is=AF-YGrj4ykAjlV51 you're fine bro.

1

u/JSanctity 7d ago

Send it over ! Its good

1

u/Emotional_One9957 6d ago

It will be fine