Timing engine

[x Spades x]

Hey Fellas,

I'm just about done with prepping the new engine. I've swapped over all of my parts including the Schrick 288/280 cams w/ DLC followers. Im trying to time the engine, and running into an "issue".

So I have the TD. Pin on the block a s the bridge on the head. The ca.s are perfectly time and bridge in place. I then install the vanos intake/exhaust hubs and hand tight the bolts.. I've gotten both sweet spots on the splines and insert the vanos. Now I check the bridge and the cams are still in time... bit after a rotation of the crank, both ca.s are slightly of timing.

Reinstalled the vanos 3 tines atimes im like wtf??

And tips to keep the cams in time after vanos install?

[Mr.wReckless]

Isn't this typically due to when you torque down the VANOS to the head the final 5mm and the spring washers inside gets up under tension and wants to turn the cams?

I remember struggling with this for several hours, and seem to recall some "cheat" by offsetting the cams by whatever amount so they get perfectly in time after the VANOS is bolted down. I think I did that and kept the pin in the bridge and cam for when I tightened the VANOS too tbh..

Like I mentioned I struggled for several hours, redid VANOS install and timing and spun the crank around multiple times before I was happy with the result.

Regards

[x Spades x]

Isn't this typically due to when you torque down the VANOS to the head the final 5mm and the spring washers inside gets up under tension and wants to turn the cams?

I remember struggling with this for several hours, and seem to recall some "cheat" by offsetting the cams by whatever amount so they get perfectly in time after the VANOS is bolted down. I think I did that and kept the pin in the bridge and cam for when I tightened the VANOS too tbh..

Like I mentioned I struggled for several hours, redid VANOS install and timing and spun the crank around multiple times before I was happy with the result.

Regards

I'm on my 5th re-install, and getting frustrated...

[Icecream]

This is common when timing. How far off, less than a mm? A small amount is okay according to BMW (and my own experience). Are your tensioners installed and are you torquing the hubs down good with the bridge and crank pin in place before rotating the crank?
I had to cheat on my intake cam too.

[Cubieman]

If both cams are off cheat (bias) via the crank, if only one cam is off cheat with that particular cam before tightening the hub bolts/installing vanos.

I was in the same scenario of installing/removing VANOS way too many times until I finally just biased the crank maybe 1-2mm and all was well.

[x Spades x]

This is common when timing. How far off, less than a mm? A small amount is okay according to BMW (and my own experience). Are your tensioners installed and are you torquing the hubs down good with the bridge and crank pin in place before rotating the crank?
I had to cheat on my intake cam too.

Pin pins drop perfectly before vanos install, without even a hint of cam contact.

Splines go in and out perfectly... timing stays perfect..

slidw vanos on and Tighten 2 bolts on each hub, timing goes to shit a to the point where one pin doesn't go in.

[x Spades x]

If both cams are off cheat (bias) via the crank, if only one cam is off cheat with that particular cam before tightening the hub bolts/installing vanos.

I was in the same scenario of installing/removing VANOS way too many times until I finally just biased the crank maybe 1-2mm and all was well.

Aaah ok. Ill try that, THANKS!

[Icecream]

Pin pins drop perfectly before vanos install, without even a hint of cam contact.

Splines go in and out perfectly... timing stays perfect..

slidw vanos on and Tighten 2 bolts on each hub, timing goes to shit a to the point where one pin doesn't go in.

hmm. Vanos should be bolted up, pistons fully pushed into vanos, Id tighten 3 bolts to make sure nothing moves when turning over motor, turn only clockwise.
If the pin doesn't slide in after that, pull the bridge up, drop the pin then set the bridge down and let us know how far up the bridge sits on the end. A small amount is okay.

[sapote]

goes to shit a to the point where one pin doesn't go in.

How far off ? 15 or 30 degrees off?
Before tightening the hubs bolts, the bridge pin was aligned with the cams, but how did you know if the Vanos pistons were bottomed out on the front caps?

[x Spades x]

How far off ? 15 or 30 degrees off?
Before tightening the hubs bolts, the bridge pin was aligned with the cams, but how did you know if the Vanos pistons were bottomed out on the front caps?

The VANOS splines aren't bottomed out when installing the VANOS. The splines are suppose to stick out 4ish mm when tightened down (the only way to bottom out the splines is to install the VANOS with both pistons extended out).

Please let me know if i have this wrong.

[x Spades x]

hmm. Vanos should be bolted up, pistons fully pushed into vanos, Id tighten 3 bolts to make sure nothing moves when turning over motor, turn only clockwise.
If the pin doesn't slide in after that, pull the bridge up, drop the pin then set the bridge down and let us know how far up the bridge sits on the end. A small amount is okay.

Okay so update...

I turned the motor over and rechecked. The intake side slides in almost perfectly with BARELY feeling the cam walls and any time.

The exhaust side is a little differnt. When I push the pin in, to catches the rim SLIGHTLY... then slides in about 3/4 (while feeling the cam wall the whole time). I can then pop it down to bottom out the pin (while feeling more of the cam wall). Bridge lays flat on both sides.

[x Spades x]

One other question I have is... should each pin go into the bridge and bottom out, WITHOUT feeling any cam walls in the hole? i know there is a threshold of the bridge lifting off the head, but at that point you're about to bend the pin.

[stash1]

One other question I have is... should each pin go into the bridge and bottom out, WITHOUT feeling any cam walls in the hole? i know there is a threshold of the bridge lifting off the head, but at that point you're about to bend the pin.

Ideally, yes, but if it's that close...you'll be fine! The ECU can accommodate up to 6* + or - IIRC.

[sapote]

i know there is a threshold of the bridge lifting off the head, but at that point you're about to bend the pin.

You're not doing it right when the pin resisted during inserting.
He said: "If the pin doesn't slide in after that, pull the bridge up, drop the pin then set the bridge down and let us know how far up the bridge sits on the end. A small amount is okay."

So in this case, just lift the bridge up about 1/2", then tiling the bridge while inserting the pin so it can go through the bridge and the cam, then let the bride down until one side is touching the head, then look at the other side to see how high it is from the head, and this is the error. (you need to tell us which side is up in the air too.)

[sapote]

The VANOS splines aren't bottomed out when installing the VANOS. The splines are suppose to stick out 4ish mm when tightened down (the only way to bottom out the splines is to install the VANOS with both pistons extended out).

Please let me know if i have this wrong.

You miss my point -- I didn't say anything about the splined shaft but the vanos pistons. But I think you got the timing not too far off. Will see your update on this.

Yeah, the cams were turned CCW to set them at max retard as instructed, and so the splined shafts are pushed out. But how do you know if the splined shafts are pushed out to their max? The only way to know this is by using X-ray to see if the vanos pistons are touching the front caps. It's time to bring the car to the dentist.
Or, you can remove the front caps off, then turn the cams CCW to push the pistons pass the vanos cap holes a little, then bolt down the caps to set the pistons at their ideal retard position, without seeing the X-ray image. Now, this is the perfect cams timing position and the bridge pin should slide in the cam holes without fuss.