Buildings AHU from short block

I am treading carefully here and trying to do research before I start installing the timing components and other assessories on my rebuilt AHU. I have a few questions for he board about the installation sequence.

Set the scene: I have the block assembled, head is on torqued down, pistons are at equal heights. Cam is in TDC position.

Questions:

1. Should I put motor back to TDC in preparation for installing the timing components? Will this be too risky without there flywheel marker? Should I buy a crank lock tool?

2. How should I install the cam sprocket(method of counter-holding?)

3.i have no idea what timing the injection pump is at right now, any suggestions for installation? How should I counter hold the IP pulley for installation?

Basically what I am asking is what is the best practice for getting a TDI ready from a bare block? I’m confident just a little unsure where to take the first step.

Thanks everyone!

-Paul

Hey Paul
I would do it just like a timing belt replacement, the only issue here is that you don't have the trans installed so figuring out where crank tdc would be is an issue. I think the Bentley manual addresses this situation.

First, you don't need to worry about cylinder head cam position if the cam is removed. Also, you don't need to worry about crankshaft position (with no flywheel installed) with the cam missing because there's nothing to hit. Finally, the IP timing won't care where it is at the moment because you can always just spin the sprocket until you get to the point where you can insert the locking pin.

I would pull the cam if it isn't already out and just put stuff back together. When I got it all assembled I would set my crank tdc and reinstall my cam very close to where it can be locked down. After that I would set my pump at lock position then install the timing belt.

Alternatively you could set all that stuff and then reinstall the engine in the car and then perform the timing belt install. I think in my case I waited because clearance was such an issue with the trans six speed conversion housing installed.

Hope this helps.

Steve

Thank you for the reply! what you suggested makes sense . However I am still wondering how to torque the cam sprocket bolt without the cam spinning. I understand the counter hold too keeps the pulley/sprocket from spinning but how does one keep the cam itself from rotating? Forgive my dumb questions I’ve looked at tons of diy and faq threads and I think I’m mixing them up. Thanks!

Not much turning force on the cam through the threads when tightening the bolt. The the friction on the tapered interface between the sprocket and cam keeps it from turning.

I know some folks will have a fit about this suggestion but I see no problem keeping the cam lock in place while tightening the cam bolt PROVIDED THE SPROCKET IS HELD TO TAKE THE TORQUE.

If one does not have the "feel" to know that the sprocket tool is taking the torque then one should remove the cam lock.

A1TDI said:

Thank you for the reply! what you suggested makes sense . However I am still wondering how to torque the cam sprocket bolt without the cam spinning. I understand the counter hold too keeps the pulley/sprocket from spinning but how does one keep the cam itself from rotating? Forgive my dumb questions I’ve looked at tons of diy and faq threads and I think I’m mixing them up. Thanks!

Click to expand...

Well torquing the bolt is no big deal, you need to install the cam lock plate in the driver end side of the camshaft (review the TB install procedures about the locking plate).

Next you will need something to hold the sprocket as you tighten the bolt. I have a cheap tool I bought at HF that I modified to hold the sprocket.

The big question I think though is why you're fixating on this at this point? It's really something you worry about when you get to the process of actually installing the timing belt.

Hope this helps

Steve