Forum » General Engine Building Discussion » Tips on marking the crank pulley for true TDC

Tips on marking the crank pulley for true TDC

General Engine Building Discussion

Forum Posts

Courses

Blog

Tech Articles

Talk about engine building here. New products, tricky questions or showcase your work - If it's engine building related it's welcome here.

= Resolved threads

Page 1
Author
111 Views

I get how to find true TDC with a positive stop. My head and block have been milled so the TDC mark on the pulley isn't perfect and if I can I'd like to make a new mark in the right spot that will work with the pointer on the timing cover. I know how to use a file to make it and some white out to paint it etc... But what I can't figure out is how to manage all this.

If it makes a difference I'm on a b18c and the motor is in the car already.

If I put the degree wheel outside of the pulley it covers the pulley, and even if it was exactly the same diameter as the pulley with all the accessory belt locations it's pretty far away from the inside ring where the mark goes so a lot of potential for error.

If I sandwich the degree wheel between the timing gear and the pulley that puts the degree wheel in a useful place though it will cover some of the pointer so the pointer would be above the degree wheel some distance from where I need to mark the pulley. Bigger challenge though is I don't think I could sandwich the degree wheel in there since the pulley is tapered where it goes onto the crank and actually goes somewhat into the timing cover. I could take the timing cover off and then sandwich it but then my pointer I am trying to use is gone.

I'm thinking I could potentially do it without a degree wheel and just use some chalk or other marking device to make 2 marks on the pulley itself from the positive stop and then take the pulley off and use a protractor of similar diameter to the pulley and find the middle between the two marks to make my permanent mark. That's my best idea so far.

What are some other tips or methods people use?

I use a sharpie or paint pin first on the outer diameter of the pulley. Then I do the dead stops, and mark the position by lightly scratching in the now painted or blacked out area. I use a flexible rule to find the distance half-way between the two marks. you could also transfer the marks to something small (metal scrap, popsicle stick etc), then measure it out of the car, then put it back in and transfer center mark back to the pulley.

Good Luck!

Got it, so I was on the right track. Thanks for that. Anyone else has their personal tricks love to hear those too.

As David said, the stop gives you two points and the middle is going to be TDC and you may not need to remove the pulley in a crowded engine bay if you have access from underneath the engine

You may also be able to mark the flywheel and bellhousing for TDC - some vehicles actually have their timing marks on the flywheel.

The other one I may want to mark is the timing gear that hides behind the pulley though For that one since the cover which has the pointer on it is off it has it’s own pointer engraved in the timing cover that isn’t very good.

If I were to make the timing gear as mentioned above any tricks to hold the crank still to get the bolt tight enough on it to be able to turn it over in both directions? Easy to get the bolt tight in the pulley that sits over the gear as the pulley has a provision in it for a holder. The timing gear with the pulley removed does not and it’s very impractical to pull the tranny to be able to stop it that way. I’ve never used an impact gun on the crank as don’t think that the bearings would appreciate it. Have someone sit inside the car and press the brakes?