S54 Vanos post Beisan/DV Rebuild Timing Issue

[Arinb12]

This sounds like a lot of works to use the solid tensioner. I would just cheat the crank a little by setting it at 2 or 3mm BEFORE TDC compression, then set the cams timing with the bridge pin, and finish the rest using the normal procedure. Cheating the crank will compensate for the chain slack that normally caused the cams timing to be a little off (bridge foot lifts off on the head intake side.

I managed to find the right size socket to use today so I'm going to try this first. I like to learn and try new methods

[sapote]

This sounds like a lot of works to use the solid tensioner. I would just cheat the crank a little by setting it at 2 or 3mm BEFORE TDC compression, then set the cams timing with the bridge pin, and finish the rest using the normal procedure. Cheating the crank will compensate for the chain slack that normally caused the cams timing to be a little off (bridge foot lifts off on the head intake side.

[sapote]

Does this assume my current starting point is vanos off and hub bolts loosened?

No, you don't want to turn the crank around with the hub bolts loosened. The hub bolts loosening starts when you ready to set the cams timing with the bridge pin.

[Arinb12]

The solid tensioner is to take out any slack on the pulling side of the chain (RH side vu from front).
I would do these steps:
Loosen vanos solenoid block to release oil pressure.
With stock tensioner, turn crank to 3mm before TDC compression (stop crank at 3mm on the left of TDC ref mark).
install solid tensioner just snug. Don't tighten too tight as it pushes hard on the guide and can break it. Slowly turn crank CW to TDC (3mm more than before). Snug up tensioner if it's loosen after turning crank CW. Set cams to retarded and verify with the bridge pin.

At this point the chain should have no slack. Proceed to pretension the hubs and finish the remained steps.
After the hubs bolts are torqued to spec, install the stock tension, then rotate the crank 4 turns and check timing with bridge pin.

Does this assume my current starting point is vanos off and hub bolts loosened?

[Arinb12]

The solid tensioner is to take out any slack on the pulling side of the chain (RH side vu from front).
I would do these steps:
Loosen vanos solenoid block to release oil pressure.
With stock tensioner, turn crank to 3mm before TDC compression (stop crank at 3mm on the left of TDC ref mark).
install solid tensioner just snug. Don't tighten too tight as it pushes hard on the guide and can break it. Slowly turn crank CW to TDC (3mm more than before). Snug up tensioner if it's loosen after turning crank CW. Set cams to retarded and verify with the bridge pin.

At this point the chain should have no slack. Proceed to pretension the hubs and finish the remained steps.
After the hubs bolts are torqued to spec, install the stock tension, then rotate the crank 4 turns and check timing with bridge pin.

Thank you very much, I will try this today and report back.

I had my timing on point with the inlet, the exhaust was just on the boundary. But I've had to put in a new vanos so thought I'd do the exhaust timing again. Ended up accidentally loosening the inlet hub (wasn't thinking properly!) And now I'm having a hard time getting it timed well again on my 6th try already!

[sapote]

Could you give me the steps to use the solid chain tensioner you recommend?

The solid tensioner is to take out any slack on the pulling side of the chain (RH side vu from front).
I would do these steps:
Loosen vanos solenoid block to release oil pressure.
With stock tensioner, turn crank to 3mm before TDC compression (stop crank at 3mm on the left of TDC ref mark).
install solid tensioner just snug. Don't tighten too tight as it pushes hard on the guide and can break it. Slowly turn crank CW to TDC (3mm more than before). Snug up tensioner if it's loosen after turning crank CW. Set cams to retarded and verify with the bridge pin.

At this point the chain should have no slack. Proceed to pretension the hubs and finish the remained steps.
After the hubs bolts are torqued to spec, install the stock tension, then rotate the crank 4 turns and check timing with bridge pin.

[Arinb12]

Yes. A little shorter than A is fine as you want to be able to thread in the housing.

If I used this would it alleviate my issues with the timing always being slightly off once hubs are tightened and the engine is turned over a few times.

Therefore I would not need to bias either right?


Could you give me the steps to use the solid chain tensioner you recommend?

Should I remove original chain tensioner and install adapted one before I remove vanos? if not when do I install adapted tensioner? And when do I reinstall the original?

Thanks

[maupineda]

Have you done a DIS vanos test or even looked at your adaptations on ecuworx DME tool?

How do the spacers work? You push against them and then pull them out?

I finally could get access to my laptop

This is how the car was before any VANOS work



Here is after the first rebuild



And next the ISTA+ testing values

[sapote]

Thanks, you and Mau helped me out quite bit when I had my issues with this and it would seem I still don't have it together, maybe I shouldn't be giving advice after I've had a few..

You gave very good advices on this, so don't stop. All of us do say confuse stuff sometime.

[sapote]

Could I not leave the intake cam bolted tight, loosen the exhaust. Pull the vanos with exhaust piston and spline attached but remove the spline from intake piston (10mm/8mm spanners) and leave it fitted in the intake hub.

Then refit doing everything only for the exhaust side?

I like your better idea. Yes.

[Arinb12]

Yes. A little shorter than A is fine as you want to be able to thread in the housing.

Perfect, thank you. I was just worried of the risk of it falling into engine, but it now makes sense
this should theoretically make it all easier, with no biasing needed and minimal issue when tightening hubs down (still doing it gently 1/4 by 1/4 turn)?

[Arinb12]

Then the EX cam is retarded, so you want to cheat and set it more advanced, CW vu from front. But how does one do this correctly? To do this reliably, unfortunately you have to loosen and pull the vanos forward again then torque it to the head to avoid having backlash from vanos pistons to spline to the hub. This means both hubs have to be loosen. This means you start all over again but set the EX cam more advance from the bridge pin reference to cheat it, You could leave the IN cam at bridge pin, but I don't understand why only EX cam was retarded but not IN cam after the procedure, in this case. I suggest you cheat both cams and set them slightly advance (more CW from the pin reference and so the bridge will lift up on the EX side of the head the same amount you want to correct)

Could I not leave the intake cam bolted tight, loosen the exhaust. Pull the vanos with exhaust piston and spline attached but remove the spline from intake piston (10mm/8mm spanners) and leave it fitted in the intake hub.

Then refit doing everything only for the exhaust side?

[sapote]

Yes. A little shorter than A is fine as you want to be able to thread in the housing.

[Arinb12]

Replace the piston and spring with a socket about same length (inside the screwed housing) so it is a home made hard tensioner. The tensioner not tilt down.

Sorry, I still don't quite understand.

You mean put a socket the length of A into the hole with the arrow and refit, and then do the timing process. Once all timed and bolted up, replace the normal tensioner?

[sapote]

So if on my exhaust cam when checking after bolting up I stil have a lift on the bridge on the intake side, then I need to slightly retard the exhaust cam when timing before bolting up, or do I advance? And if so which way? Is that CCW or CW. Don't want to do the crank because intake is getting no problem

Then the EX cam is retarded, so you want to cheat and set it more advanced, CW vu from front. But how does one do this correctly? To do this reliably, unfortunately you have to loosen and pull the vanos forward again then torque it to the head to avoid having backlash from vanos pistons to spline to the hub. This means both hubs have to be loosen. This means you start all over again but set the EX cam more advance from the bridge pin reference to cheat it, You could leave the IN cam at bridge pin, but I don't understand why only EX cam was retarded but not IN cam after the procedure, in this case. I suggest you cheat both cams and set them slightly advance (more CW from the pin reference and so the bridge will lift up on the EX side of the head the same amount you want to correct)