rb20 timing belt slack

[legit240sx]

so i have a small amount of slack in my timing belt from my tensioner to my intake cam gear(tensioner is tight!). reason being the intake cam is a pain in the butt to rotate so with the rubber trying to push the cam it creates some slack. the only thing im worried about is jumpin teeth. Would any one say this a problem or just don't worry about it.. Would a kelar timing belt resove the problem?
thanks

[Carl H]

wait, what?
can you be a bit clearer?
why are you trying to rotate the intake cam?

[legit240sx]

(Not my engine in the picture, picture is just for reference)
Sorry, hope this is a better explanation of the situation.

To start off,
My timing belt is already on, timed correctly, and tightened by the tensioner.
The intake cam was a pain in the butt to turn by hand before the timing belt was installed.

Now when you turn the crank by hand, timing belt being installed, it creates slack in the timing belt.
The slack happens because the belt is trying to turn the intake cam, which requires more force than usual to turn.
The slack is only in the area demonstrated in the picture (the rest of the belt in stinkin tight!).



I can only guess that this is abnormal considering how easy the exhaust cam moves.
My question is will I jump teeth or damage the belt if keep it the way it is?
Also, if it will be a problem would a kevlar belt solve it?

[240z4u]

Honestly, do you even have to ask this question? I normally ignore posts like this, but this is so retarded I have to chime in.

If your cam won't turn now, how the hell is it going to turn with your fancy pants belt installed? Quit being a lazyass and figure out why that cam is binding.

Oh, and to add some content. Did you remove the cam caps on your intake cam? if you did, and you didn't put them back exactly the way they came apart you can end up with a binding cam.

[legit240sx]

Honestly do you ask a question before you blindly "chime in”?
Is it possible I already have it under control and figured out...
Am I seriously going to ignore the reason behind my cam's difficulty?
I just feel like blowing up my engine because I'm obviously completely lazy...

Question still stands.

[gawdzilla]

is your intake cam stuck, or is it just getting hard to turn because of compression? if the cam gear is stuck or abnormally hard to turn, there is obviously something wrong, and getting a stronger belt isn't the solution.

as the belt rotates, it will slack in different spots depending where the tension is and what part of the stroke the valves/pistons are in. that's why some people tension the belt, rotate it a few revolutions and re-tension.

[legit240sx]

The intake cam is abnorally difficult to turn, checked and measure the tollerances and all are in spec of each other. Won't lie had one bearing surface almost seize on me but cought it in time and made the adjustments. all other bearing surfaces are just fine otherwise.

Good to know, ill see if i can't get any more out of my tensioner.
main reason i posted was just to make sure i don't kill my valvetrain by skippin a tooth

[gawdzilla]

if that's the case, don't even bother trying to turn it over with the timing belt. something is definitely wrong. it will skip if you try to force it. kind of like trying to break the crank bolt loose while holding the cam gears still.

[legit240sx]

it's not hard to turn the engine over by hand with a ratchet and the timing belt attached. the only pain in the butt was getting it to line up with the timing marks when installing the belt.
heck maybe i sould just invest in a new head....

[240z4u]

Honestly do you ask a question before you blindly "chime in”?
Is it possible I already have it under control and figured out...
Am I seriously going to ignore the reason behind my cam's difficulty?
I just feel like blowing up my engine because I'm obviously completely lazy...

Question still stands.

I use the information presented in the post, you are asking for reassurance that your cam will magically start spinning freely once you crank the motor over.

What adjustment did you make to your bearing surface when it attempted to seize? Are you sure your cam isn't bent?

Evan

[legit240sx]

plastigauged all intake bearing surfaces which were between .025 to .038 except for the bearing that was about to seize.
honed the bad bearing surface out until .038. i didn't check for a bend.

[Carl H]

did you use a different cam cap on the head than what came from factory?
just because you honed it out till it was in spec with the rest does NOT mean it is straight, a line bore should have been performed to true it up as it will not match the rest.

[240z4u]

did you use a different cam cap on the head than what came from factory?
just because you honed it out till it was in spec with the rest does NOT mean it is straight, a line bore should have been performed to true it up as it will not match the rest.

This is exactly what I am thinking the problem is. Are you 100% sure the cam caps were put back where they were removed from? I had a cam cap spun around on my WRX and it made the cam a b**** to turn. I found the error and swapped back and the binding was gone.

Evan

[legit240sx]

caps are in their designated places facing the correct direction.
two intake cam caps were replace #2 and #5 with no line bore.
#5 showed no signs of seizing.

[Carl H]

i am willing to bet money that the cam cap replacement is the culprit.

[240z4u]

i am willing to bet money that the cam cap replacement is the culprit.

Definitely.

[legit240sx]

head getting ready for its line bore.
any thing else i should do while in the machine shop?

[Carl H]

clean it and fit new valve stem seals.
a proper valve job wouldnt hurt.

[Lozer]

port and polish with some flow bench work for a couple extra hp.