while checking my timing
06-25-2012, 06:34 PM
#1
Thread Starter
while checking my timing
SOOO.... while trying to figure out my sensors for my mega squirt conversion i decided to check my timing. ya both cams are off 3 teeth (clockwise) from the pointers at TDC compression . i used my finger in the spark plug hole to find compression stroke (air blows out etc) and at TDC... off.....
how in the hell did that happen? looked good when it was on the engine stand and i rotated the engine my hand....... I'm using a porkensioner with a gates belt....
thoughts?
how in the hell did that happen? looked good when it was on the engine stand and i rotated the engine my hand....... I'm using a porkensioner with a gates belt....
thoughts?
06-25-2012, 08:14 PM
#3
Three Wheelin'
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did you rotate it more than once? I think after you install the belt and rotate to -0 to check the timing, you must rotate two full turns and re-check all timing marks. I did this 3 times (total of 6 rotations) to confirm.
Sounds like someone either didnt lock the flywheel, and / or had the timing marks incorrect when they strung the belt. Good catch however.
Sounds like someone either didnt lock the flywheel, and / or had the timing marks incorrect when they strung the belt. Good catch however.
06-25-2012, 08:43 PM
#6
Captain Obvious
Super User
Super User
Rotating or jot rotating will not do this.
I had this happen to me before on the '83. A piece of the timing belt cover slid down the belt and wrapped itself around the crank pulley. Everytime the crank got to where the plastic piece was on the crank, it would slip slightly.
I had this happen to me before on the '83. A piece of the timing belt cover slid down the belt and wrapped itself around the crank pulley. Everytime the crank got to where the plastic piece was on the crank, it would slip slightly.
06-25-2012, 09:21 PM
#7
Thread Starter
after doing a complete rotation about 7 times, looks like the drivers cam is ATDC maybe 4 degrees, and passenger is about 6 ATDC till they are exactly on the mark..... do i need offset keyways? I'm not going to button this back up till i get the starter installed and try cranking it a few times that way.
just to be safe.
just to be safe.
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06-25-2012, 09:48 PM
#8
Inventor
Rennlist Member
Rennlist Member
The belt will stretch another ~2° degrees on the 1-4 (pass.) side once it settles in. I would say that one is still one tooth (7.5° crank) off.
Hard to say for sure until you spin the starter.
Hard to say for sure until you spin the starter.
06-25-2012, 09:50 PM
#9
Captain Obvious
Super User
Super User
As far as I know, the 16v timings always look off. As long as they are not kore than half a tooth off, it's accaptable. Offset keys are not factory spec but remember reading that others have used it in the past.
