Thread: Crank pulley Measurements, Help

So I have an aftermarket pulley, not a nissan oem one. It has TDC and 2 other marks. Now seeing if someone has an oem pulley laying aroung and can measure how far the 15 degree mark is away from the TDC mark. This will help me pinpoint what these marks actually represent on my pulley. I measured mine and know how far they are from TDC, so whatever you guys can come up with will help. Thanks.

Nobody has a spare pulley or motor with pulley on it sitting around that they could do a quick measurement?? I would rally appreciate it.

come on, anyone. It woud really help me out. If anyone could even get under there and measure distance from TDC mark to the 15degree mark, or basically the 13-17 degree mark and I will figure rest out.

I just saw this... Give me a minute I have a spare one around here somewhere

there is 3 lines from it. 2.37~, 2.1, 1.8 this is cm by the way.. from the TDC mark

Hey awsome, thanks a lot man.

So the 1.8 being the closest to TDC correct? then a mark at 2.1 then one at 2.37? Not the distance between each mark right all from TDC? Just trying to clear it up.

And shouldnt there be a five lines after TDC? 5-10-13-15 and 20 degrees? Do you have a pic?

shit i don't know thats just how my spare one is

lol, okay thanks for the help though. I am just going by the fsm pics I see on here in the post on timing your motor.

Anyone else have a spare stock pulley around or want to measure the one on their car for me?? Right now I am just guessing my marks are 13-15 degress.

Don't take this the wrong way, but you don't need anyone to measure anything for you. You can do this yourself. And since you say it is aftermarket, there is no telling what diameter your pulley is which means our measurements won't necessarily work for you.

You say you already know where TDC is... And then you have two other marks. What degree do they represent? Measure that yourself with a protractor and you're done.

Or, if you don't want to go buy a $1 plastic angle measuring device you can do this another way.
Trace the outer diameter of the pulley (where the marks are) on a piece of paper and measure the diameter. (Or use a ribbon around the lip with the marks to get the circumference.) Half that to get the radius. Then use the formula for the circumference of a circle ( 2·π·r ) to find the circumference. Divide the circumference by 360 to get the distance of one degree arc around the circumference. Measure the distance of the arc between the TDC mark and the next mark and divide by the single degree arc you calculated before and that will tell you how many degrees it is.

Here is an example.

(Diameter) d = 150mm

(Radius) r = d / 2 = 75mm

(Circumference) c = 2·π·r = 2 · 3.14159 · 75mm = 471.2385mm

(Degree arc) da = c / 360 = 471.2385mm / 360 = 1.309mm

Every 1.309mm along the outside of the pulley would be 1 degree.