Hey everyone, I just rebuilt my 1991 honda crx engine due to my old one being blown up. I have a freshly built block with new oil pump, pistons, rods, and the head was completely re-done. I was just curious if I would need a timing light tool for the car or if I will be ok to just re-align the belt and it'll be ready to go? I appreciate any help and advice!

 

timing belt and timing light are only loosely related. you set the timing belt up by aligning the marks. i have done TB changes with no timing light. the teeth make it very difficult to screw up, so provided you have found TDC on #1 cylinder, you would back off of that, then rotate the cam to TDC #1 cylinder, then bring the bottom end back to TDC #1 cylinder, take all the slack out of the non-tensioner side of the belt and run the teeth into the sprocket. when everything looks good, you tighten the tensioner, and voila! you have a perfectly timed longblock. turn it over by hand a few times to check for interferance and to spread the assembly lube around before startup. then return to TDC and install your dizzy.

now, your cam drives the distributor, which is where the timing light goes. It's for ignition timing, not engine (piston/valve) timing. it's loosely related in that when the #1 cylinder fires, the strobe shows you the timing mark on the crank pulley which should be around 16-18 deg BTDC if I recall correctly. so in a way a timing light could I guess tell you if your relationship between the cam and crank is messed up... but not until it's already been running at which point you may have caused some damage if the head has been decked.