S54 schrick- build and timing issues.

[BMWfanz]

Hello guys! I have swapped e30 S54- 6 years ago build engine: JE stock compression ratio pistons, stock cams, supertech valve springs and valves. Drove it around 20k kms- all was ok, have CSL conversion kit- Schrick 288/280 Valve Lift 12,50 have read forums- this combo worked with vanos (Not high lift). So, installed airbox, cams- tuned car- drove it 2000kms- HTE tune. When we were in tune process- Hassan told me that i have big overlap on exhaust- car driven ok- but i thought- low power, as on stock cams, maybe very little increase. So, i''ve used tool32 for vanos test- Intake is ok- all 60 degrees work- exhaust- only 15-17 degrees. As i thought- it could be vanos spindle issue or timing- so today retimed engine with OEM tools, started engine- perfect idle, worked around 20 mins- and after this I decided to run the vanos tool32 test again. Intake- work perfectly from zero to 60 degrees, now this: exhaust advance cam- all is ok, worked 10 seconds- and when it tried to reach 48 degrees it had mechanical noise and ive turned it off- i think its bented exhaust valves. Now it is a question- When i was building the engine-i've flattened head surfaces and engine block machined too. Now i have a question- could JE pistons have valve piston notches differently from OEM ones or the reason piston hit valve is my surface machinary? As i''ve read on all forums- stock pistons work perfectly with 288/280 12.5 lift without limitation of degrees. Or it is timing issue? But i've rotated engine maybe 10-12 times and tools were in right positions. Need your advice and maybe build engine expirience

[sapote]

1. Hassan told me that i have big overlap on exhaust. i''ve used tool32 for vanos test- Intake is ok- all 60 degrees work- exhaust- only 15-17 degrees.
2. when it tried to reach 48 degrees exhaust cam- it had mechanical noise and ive turned it off- i think its bented exhaust valves.

1. If it had too much exhaust overlap, this means the ex cam was too retarded, -15 or -17* before TDC. The EX vanos piston has the motion range of 45*, and so we should expect the Tool32 should report the cam range from x to y with a total 45 deg, not just 17 deg. What limited the cam to only 17* changes?
2. 48 or actually minus -48 is 48* before TDC. More advance ex means less chance for ex valves hitting pistons -- valves closed sooner than pistons rose to TDC. I would say if the valves are bent, then this happened when they were retarded and not advanced.

Case 1 should have more chances of hitting the ex valves and case 2.

[BMWfanz]

1. If it had too much exhaust overlap, this means the ex cam was too retarded, -15 or -17* before TDC. The EX vanos piston has the motion range of 45*, and so we should expect the Tool32 should report the cam range from x to y with a total 45 deg, not just 17 deg. What limited the cam to only 17* changes?
2. 48 or actually minus -48 is 48* before TDC. More advance ex means less chance for ex valves hitting pistons -- valves closed sooner than pistons rose to TDC. I would say if the valves are bent, then this happened when they were retarded and not advanced.

Case 1 should have more chances of hitting the ex valves and case 2.

Thank you for your detailed answer. Yes, I have a mistake in my message- valves bented in retard test phase, not in advance. When I was disabling vanos- the spindle from vanos to camshaft was not in right tooth position- that was the reason that exhaust vanos had only 17 degrees range.

[sapote]

Thank you for your detailed answer. Yes, I have a mistake in my message- valves bented in retard test phase, not in advance. When I was disabling vanos- the spindle from vanos to camshaft was not in right tooth position- that was the reason that exhaust vanos had only 17 degrees range.

The valve bending accident wouldn’t happen if the crank turning test was done after timing setting regardless the spline shaft was a tooth wrong.

[eacmen]

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?

[BMWfanz]

The valve bending accident wouldn’t happen if the crank turning test was done after timing setting regardless the spline shaft was a tooth wrong.

Let me clarify: issue with low range degrees was before last timing procedure. Valve benting happened after all correct timing and vanos sweet tooth position. Question is there any cases of tuned JE pistons and piston notches are different from OEM ones

[sapote]

Let me clarify: issue with low range degrees was before last timing procedure. Valve benting happened after all correct timing and vanos sweet tooth position. Question is there any cases of tuned JE pistons and piston notches are different from OEM ones

During and after vanos timing done, the EX cam was at its max retarded pos (vanos piston at its max forward pos) and the bridge pin aligned with the cam hole. Why during manually rotating the crank for a final test, the valve-piston interference wasn't detected regardless the condition of JE pistons or the cams?

[BMWfanz]

During and after vanos timing done, the EX cam was at its max retarded pos (vanos piston at its max forward pos) and the bridge pin aligned with the cam hole. Why during manually rotating the crank for a final test, the valve-piston interference wasn't detected regardless the condition of JE pistons or the cams?

I have no answer on this question- only that it touched slightly and it was not sensible. Will open valve cover today and check what is wrong and check the valves inside engine with endoscope

[Slideways]

Let me clarify: issue with low range degrees was before last timing procedure. Valve benting happened after all correct timing and vanos sweet tooth position. Question is there any cases of tuned JE pistons and piston notches are different from OEM ones

Did you push both splined shafts into the VANOS unit to retard both VANOS pistons before installing the VANOS unit onto the head?

There is that possibility with the aftermarket pistons and/or the machine shop removed more material from the block and cylinder head than your setup can handle. It might require a thicker head gasket.

[BMWfanz]

Did you push both splined shafts into the VANOS unit to retard both VANOS pistons before installing the VANOS unit onto the head?

There is that possibility with the aftermarket pistons and/or the machine shop removed more material from the block and cylinder head than your setup can handle. It might require a thicker head gasket.

Yes, splined shafts moved into unit until reach the vanos piston caps. Car was running perfectly for 20 mins until i've done vanos test, exactly when last phase of exhaust retarding test- vanos reached maximim 48 degrees and i've heared mechanical noise and turned car off. Will update soon with more info when sort it out.

[BMWfanz]

Update: valves reached the pistons. Will measure valve lift without cam and spring in TDC and post results soon. Seems like I have no valve clearance after head and block machinery.

[BMWfanz]

As it seems- notches on stock OEM bmw pistons are slightly deeper

[bmwfnatic]

Update: valves reached the pistons. Will measure valve lift without cam and spring in TDC and post results soon. Seems like I have no valve clearance after head and block machinery.

Probably doesn’t have anything to do with having a skimmed head and decked block, there is plenty of margin there, but I suppose with aftermarket components I am not sure.

[sapote]

, i''ve used tool32 for vanos test- Intake is ok- all 60 degrees work- exhaust- only 15-17 degrees.

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.

[Ryan_R]

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.