S54 schrick- build and timing issues.

[BMWfanz]

This limited range of EX cam only 17 deg has been bugging me. The normal variable range is 45 deg: from -83 to -128 (valves open before TDC). What stopped Tool32 to vary the cam more than 17 deg range? This tells me the initial timing setting was so wrong that the EX piston hit the front cap before it reaching -83*. It had no problem advancing the cam to -128 (max advanced pos), then only able to move to -111* (128 - 17 = 111) and piston hit the cap limit). This means the vanos hub bolts were torqued down when the EX cam was at -111 instead of -83, but this also means the bridge pin would never align to the cam testing hole.

Of course if the vanos cap stopped the piston at -111 then EX valves closed way before the pistons are at TDC and no bent valves ever happened in this case.

Let me clarify: 17 degrees range was on exhaust vanos was the reason why I retimed engine. When I started checking timing- it was so wrong that exhaust pin was missed, I have a photo too ( see pin position and plate position on second photo). I've drove on it maybe 2-3k kilometers on wrong timed engine.Then I retimed engine. When I disassembled vanos I"ve marked vanos spindles and when tried to install it on marked position- it wasn't in sweet tooth position, on marked tooth only half of the range as I pushed spindle by hand. Then I"ve done timing procedure again, installed pins, checked valve hubs maxim right position as tis said, marked sweet tooth position, pulled vanos pistons maximum inside of the vanos module, then installed vanos, torqued 2 hub bolts, rotated engine 7-8 circles, checked the pins position with timing tools, then again rotated engine 3-4 times- checked with final tool (which is 1 pin) as tis said and completed procedure. Then after 20 mins of engine work i launched tool 32 and vanos test. I was sitting in a car with laptop and when exhaust cam retard on 45-48 degrees- valves were bented.

[BMWfanz]

I can confirm the JE pistons have more than enough valve relief. I didn’t measure the stock pistons but with .003” taken off the head and .005 taken off the block, I had 10.8mm piston to valve clearance at TDC on the intake side(adding in 1mm for safety, so 11.8 before contact). This is enough clearance to run any production cam offered for the s54, even the Schrick high lift or Cat cams 14.5mm lift cam.
sounds like a timing issue, not piston related.

Intake is ok, have you measured exhaust one?

[BMWfanz]

Stupid question but are you sure the intake and exhaust cams aren't swapped? They look very similar. The intake cam has 6 tangs on the sensor wheel and the exhaust has 7 tangs.

Sounds like a mechanical timing issue to me. What procedure did you use to set timing?

Nope, cams aren't swapped)

[Ryan_R]

Intake is ok, have you measured exhaust one?

Yes measured exhaust as well and it was the same, plenty of clearance for any cam. I don’t have the exact numbers for that side in front of me, I’d have to go back through my notes.

[BMWfanz]

Yes measured exhaust as well and it was the same, plenty of clearance for any cam. I don’t have the exact numbers for that side in front of me, I’d have to go back through my notes.

I think on exhaust side are not so much space, or I don't understand why 14mm high lift cams don't work with vanos. When I've looked for a cams- working vanos and most agressive cam angles and lift was chosen.

[sapote]

photo). I've drove on it maybe 2-3k kilometers on wrong timed engine..

And no error codes popped up? It should.

[BMWfanz]

And no error codes popped up? It should.

No codes at all...

[Ryan_R]

I think on exhaust side are not so much space, or I don't understand why 14mm high lift cams don't work with vanos. When I've looked for a cams- working vanos and most agressive cam angles and lift was chosen.

I checked my notebook from the build. 12.7mm clearance on intake 10.8mm clearance on exhaust, with safety margins built in.

The most aggressive off the shelf cam I could find was the cat cams 1301808 profile. 10mm/8mm lift at tdc. So there is still plenty of room even with that profile.

[sapote]

No codes at all...

With the EX cam only could vary within 17* instead of 45*, I would expect that the DME detected the commanded angle and the actual angle to be with a big difference then it should pop the errors. I.e DME wanted to retard to -83 but the cam only got to -111 as I pointed out before.

[sapote]

1. I have a photo too ( see pin position and plate position on second photo).
2. When I disassembled vanos I"ve marked vanos spindles and when tried to install it on marked position- it wasn't in sweet tooth position, on marked tooth only half of the range as I pushed spindle by hand. Then I"ve done timing procedure again, installed pins, checked valve hubs maxim right position as tis said, marked sweet tooth position, pulled vanos pistons maximum inside of the vanos module, then installed vanos, torqued 2 hub bolts, rotated engine 7-8 circles,
3. checked the pins position with timing tools, then again rotated engine 3-4 times- checked with final tool (which is 1 pin) as tis said and completed procedure. Then after 20 mins of engine work i launched tool 32 and vanos test. I was sitting in a car with laptop and when exhaust cam retard on 45-48 degrees- valves were bented.

1. The pic proves the theory that the EX piston hit the cover cap at -111 deg instead of max retarded -83: 111 - 83 = 28 deg crank, so cam deg is 14 deg different, which the pic shows.
2. I read your steps and it's not clear to me if you had done it right. List in detail all the steps involved when it was done.
"pulled vanos pistons maximum inside of the vanos module, then installed vanos, torqued 2 hub bolts, rotated engine 7-8 circles"
This seems to be the bad part: pulled the vanos piston max out means toward the rear, which is opposite of what you want to have the piston pushed to its max forward (hitting the front piston cap). If you did pulled the piston rearward to max, and then torqued the hub bolts down with the EX cam aligned with the pin, then when the DME moved the piston forward to it max retarded pos, then the cam was retarded further than -83*, say -70, then the EX valves were still wide opened when piston moved up TDC then hit the valves.

You shouldn't care about getting the sweet tooth as it's not causing the problem.

3. Yes, you had rotated the crank and check with the pin alright, but this hidden the problem and bent the valves later. Why during this crank rotating check that the piston to valves interference wasn't detected? BC the EX piston was still not moved toward the cap yet.
The only sure way to verify the timing is to ensure that the vanos piston hitting the cap and the cam hole aligned with the bridge pin and the crank at TDC compression. you have 2 parts right but you didn't know where was the vanos piston.

[BMWfanz]

1. The pic proves the theory that the EX piston hit the cover cap at -111 deg instead of max retarded -83: 111 - 83 = 28 deg crank, so cam deg is 14 deg different, which the pic shows.
2. I read your steps and it's not clear to me if you had done it right. List in detail all the steps involved when it was done.
"pulled vanos pistons maximum inside of the vanos module, then installed vanos, torqued 2 hub bolts, rotated engine 7-8 circles"
This seems to be the bad part: pulled the vanos piston max out means toward the rear, which is opposite of what you want to have the piston pushed to its max forward (hitting the front piston cap). If you did pulled the piston rearward to max, and then torqued the hub bolts down with the EX cam aligned with the pin, then when the DME moved the piston forward to it max retarded pos, then the cam was retarded further than -83*, say -70, then the EX valves were still wide opened when piston moved up TDC then hit the valves.

You shouldn't care about getting the sweet tooth as it's not causing the problem.

3. Yes, you had rotated the crank and check with the pin alright, but this hidden the problem and bent the valves later. Why during this crank rotating check that the piston to valves interference wasn't detected? BC the EX piston was still not moved toward the cap yet.
The only sure way to verify the timing is to ensure that the vanos piston hitting the cap and the cam hole aligned with the bridge pin and the crank at TDC compression. you have 2 parts right but you didn't know where was the vanos piston.

I will check timing again when will reassemble everything. Maybe i have not correctly described timing process that 've done in text. Will update soon. Thank you!

[BMWfanz]

Confirmed problem- timing is OK, problem was with surfaced engine block and head. Now will try to find adequate head gasket and maybe will machine pistons for deeper valve counterbores. If someone has measured piston to valve clearence in schrick 288/280 12.5 lift cams- will be appreciate for info.

[Slideways]

Confirmed problem- timing is OK, problem was with surfaced engine block and head. Now will try to find adequate head gasket and maybe will machine pistons for deeper valve counterbores. If someone has measured piston to valve clearence in schrick 288/280 12.5 lift cams- will be appreciate for info.

Yeah, it sounded like you timed it right, but it needed a thicker headgasket. Cometic makes multiple S54 headgaskets in different thicknesses.

[BMWfanz]

Update: one exhaust valve bented, will measure head height and will decide which gasket thikness to choose

[sapote]

Update: one exhaust valve bented, will measure head height and will decide which gasket thikness to choose

Not clear to me bent valve due to wrong timing or head clearance.