Timing

[Mazinger]

Hello, getting ready to rebuild this 1500 I got a few months ago. I've searched through the many timing posts but have not found the answer to my question. Checking it over prior to disassembly I find that when the crank mark is at tdc, the cam mark is off about 1/2 tooth. It looks like the block has never been rebuilt but the head has definitely been redone, there are signs, including a small circular stamp from some machine shop. Could this condition be caused by the head having been over surfaced? If I moved the timing to the next tooth, it would then be too far. What else could cause this? Just trying to plan ahead for the rebuild. Sadly, I can check the transmission marks since it's already on a stand. Thanks in advance

 

[Dr.Jeff]

The timing marks at the front pulley can easily be off. It is adjustable and may not be set correctly. Unfortunately the best way to really verify it is by checking the flywheel. However I usually find the cam to be around 1/2 to almost 1 tooth off once everything is properly verified. And that is with a unmodified engine/ head, like yours. So it could indeed be off with no real explanation.

 

[dllubin]

The first thing I would do is check to see that the timing mark on the pulley matches the timing mark on the flywheel. The scale for the pulley mark is adjustable so there is no guarantee that it is set correctly. The mark on the flywheel is not adjustable so it should be correct as long as the flywheel was correctly attached (Unfortunately, it can be bolted on to an "incorrect" position).

If the head was shaved enough, you may need to go to an adjustable cam sprocket and it may also require a 1300 belt tensioner. See what tensioner is on there now for clues.

 

[ng_randolph]

Hello, getting ready to rebuild this 1500 I got a few months ago. I've searched through the many timing posts but have not found the answer to my question. Checking it over prior to disassembly I find that when the crank mark is at tdc, the cam mark is off about 1/2 tooth. It looks like the block has never been rebuilt but the head has definitely been redone, there are signs, including a small circular stamp from some machine shop. Could this condition be caused by the head having been over surfaced? If I moved the timing to the next tooth, it would then be too far. What else could cause this? Just trying to plan ahead for the rebuild. Sadly, I can check the transmission marks since it's already on a stand. Thanks in advance View attachment 82603View attachment 82604

If you remove the crank pulley, you will see timing marks on the timing belt sprocket and the rear main seal carrier. These will be more reliable than the marks you showed, since, as others have said, the sheet metal marker can be off.

 

[Mazinger]

If you remove the crank pulley, you will see timing marks on the timing belt sprocket and the rear main seal carrier. These will be more reliable than the marks you showed, since, as others have said, the sheet metal marker can be off.

Awesome, thank you! I will look at this.

 

[Mazinger]

The first thing I would do is check to see that the timing mark on the pulley matches the timing mark on the flywheel. The scale for the pulley mark is adjustable so there is no guarantee that it is set correctly. The mark on the flywheel is not adjustable so it should be correct as long as the flywheel was correctly attached (Unfortunately, it can be bolted on to an "incorrect" position).

If the head was shaved enough, you may need to go to an adjustable cam sprocket and it may also require a 1300 belt tensioner. See what tensioner is on there now for clues.

Thank you, I hope that's not the case, I'll know more once apart. With the engine on the stand, the flywheel marks are not an option. I rather not have to drop it and install it just to check unless last option. I agree that the pulley mark might have moved over the years. I'll check the crank sproket as also suggested, that should give a more precise measurement. Thanks again,

 

[Dan Sarandrea (Phila)]

If you remove the crank pulley, you will see timing marks on the timing belt sprocket and the rear main seal carrier. These will be more reliable than the marks you showed, since, as others have said, the sheet metal marker can be off.

Especially handy if you are dealing with just the engine and not with engine + transaxle attached, as the dot on the flywheel is referenced against notches in the transaxle bell housing.