PDA

View Full Version : Winfred or Bill - question regarding timing/crank wheel



Jon K
04-16-2006, 03:12 PM
I am using the stock 60 - 2 crank wheel on the M50 for my MegaSquirt standalone project. I don't have a wrench big enough or a socket short enough to turn the engine to TDC (plus my TDC mark is all gunked) and was wondering if you guys could help me out.

I am trying to determine what tooth the Crank Position Sensor is over while the engine is at TDC... I guess the count starts from the missing teeth? I unfortunately can't get my car to TDC right now and my M50 on the engine stand has no crank position sensor on it :(

Could someone maybe put their M50 at TDC and tell me which tooth the crank position sensor is on and if its on the leading edge, falling edge, or dead center of the tooth? Thanks.

winfred
04-16-2006, 03:34 PM
ill try to remember to check tomorrow

Jon K
04-16-2006, 03:36 PM
ill try to remember to check tomorrow


No rush - I'll shoot you a PM or something - are the teeth on the wheel pointed or squared? I cannot remember.

Also, have any good Crank Position Sensors laying around?

winfred
04-16-2006, 03:46 PM
square and probably, id go new on my own car as they can crap out after handling


No rush - I'll shoot you a PM or something - are the teeth on the wheel pointed or squared? I cannot remember.

Also, have any good Crank Position Sensors laying around?

Jon K
04-16-2006, 04:41 PM
hm - ok. i will prob just swap mine over when i do the electricals.

winfred
04-17-2006, 02:35 PM
theres 5 teeth to the left of the oIt to the gap, the sensor is between the 2nd and 3rd but mostly over the 2nd starting at the oIt

............................... SS
..................... gap t t t t t t t t
................................... oIt

Jon K
04-17-2006, 02:39 PM
theres 5 teeth to the left of the oIt to the gap, the sensor is between the 2nd and 3rd but mostly over the 2nd starting at the oIt

............................... SS
..................... gap t t t t t t t t
................................... oIt


**** thanks winfred, i totally forgot to ask you about it - sweet, you pulled thru. I am trying to make out your explaination. The forum messed up your ASCII drawing - hm. MS Paint? thanks so much. Can you check my other thread about M50 rebuild - had some questions in there. Thanks again.

winfred
04-17-2006, 05:56 PM
different screen resolution? 1024x768 looked good at work and here at home, you just want one of my wonderful shitty hand drawings run through the scanner, i guess i could of numbered them the other way, it's gap 5 4 3 2 1oIt


**** thanks winfred, i totally forgot to ask you about it - sweet, you pulled thru. I am trying to make out your explaination. The forum messed up your ASCII drawing - hm. MS Paint? thanks so much. Can you check my other thread about M50 rebuild - had some questions in there. Thanks again.

yaofeng
04-17-2006, 06:13 PM
I
Could someone maybe put their M50 at TDC and tell me which tooth the crank position sensor is on and if its on the leading edge, falling edge, or dead center of the tooth? Thanks.

See picture.

http://i21.photobucket.com/albums/b274/yaofengchen/BMW_95_525i/DSC_1733.jpg
There is a mark on the timing cover. The 0 deg TDC mark on the flex damper lines up with the mark on the timing cover at No. 1 piston TDC.

yaofeng
04-17-2006, 06:17 PM
Hope this picture is better.
http://i21.photobucket.com/albums/b274/yaofengchen/BMW_95_525i/DSC_1733a.jpg

winfred
04-17-2006, 06:20 PM
yea, that

Jon K
04-17-2006, 06:29 PM
LOL thanks guys!


Winfred thanks for the help man

Still not sure what to do about my bent timing chain guide mount pin... its in the thread:

http://www.bimmer.info/forum/showthread.php?t=20996

yaofeng
04-17-2006, 06:56 PM
After 9/94, BMW changed the timing chain guide from cast aluminum to plastic. With it the pin design is also changed. My hope (and it will be yours too) that the way the timing chain guide pin is inserted into the block remains the same. If it is, it is either shrink fit or pressed in. See picture of the new style timing chain guide pin. There is no need to have a snap ring lock for the chain guide anymore with the plastic guide. The plastic guide snaps into the pin to be locked in place.

http://i21.photobucket.com/albums/b274/yaofengchen/BMW_95_525i/DSC_2706.jpg

You can then get the bent pin out. Get the new style timing chain guide and pin. Oh.. There is more. With the plastic chain guide, the chain tensioner is also different. The tensioner is no longer adjustable. See picture of new and old timing chain tensioner side by side.

http://i21.photobucket.com/albums/b274/yaofengchen/BMW_95_525i/DSC_1742.jpg

You will note that I used the new plastic chain guide and the new tensioner. But I kept the old pin. Because mine was not bent, but more so because I don't know how to remove the pin. I made an aluminum bushing out of the old alumnum guide to make up the difference in thickness between the aluminum guide and the plastic and also used the old snap ring to lock the plastic guide in place.

http://i21.photobucket.com/albums/b274/yaofengchen/BMW_95_525i/DSC_1710.jpg

But again I didn't have a choice because I did not remove the head. So there is no way to get an aluminum guide back in with the head on. In your case it may be simpler to just replact the pin (with the old style one) if you can pull it out.

winfred
04-17-2006, 06:56 PM
smacking it carefully with lead or brass will probably get the job done


LOL thanks guys!


Winfred thanks for the help man

Still not sure what to do about my bent timing chain guide mount pin... its in the thread:

http://www.bimmer.info/forum/showthread.php?t=20996

Jon K
04-17-2006, 07:30 PM
smacking it carefully with lead or brass will probably get the job done


Going to tap it counter bent with lead hammer and straighten the bitch out. My other question is:

In the genius of my mind, I decided to try and "Lock" the flywheel in place by using grade 8 bolts threaded into the flywheel bolt holes and letting one rest against the engine stand spider as I undid the crank bolt - didn't work, bolt broke but not only did the bolt break, but it F-d some sort of "sleeve" that looks like its pressed in. There is only one of these sleeves in the end. Forgot to get a pic of it before I left the garage. Any idea on what it is and how to replace it since I smushed the old one?

Jon K
04-17-2006, 07:30 PM
Yaofeng - you're new here but you're very helpful!

winfred
04-17-2006, 07:40 PM
the alignment dowl around one flywheel bolt hole? should be able to get a new one cheep and it takes a couple seconds to knock in once you get the old one out with pliers/channel locks/vicegrips


Going to tap it counter bent with lead hammer and straighten the bitch out. My other question is:

In the genius of my mind, I decided to try and "Lock" the flywheel in place by using grade 8 bolts threaded into the flywheel bolt holes and letting one rest against the engine stand spider as I undid the crank bolt - didn't work, bolt broke but not only did the bolt break, but it F-d some sort of "sleeve" that looks like its pressed in. There is only one of these sleeves in the end. Forgot to get a pic of it before I left the garage. Any idea on what it is and how to replace it since I smushed the old one?

Jon K
04-17-2006, 09:22 PM
Winfred/Yaofeng - that image with the "TDC" pic doesn't look right. The bentley says the TDC indicator is a "O/T" mark on the wheel... and the gap for missing teeth is usually on the other side of hte CPS... Help!!!

yaofeng
04-18-2006, 01:02 AM
Going to tap it counter bent with lead hammer and straighten the bitch out. My other question is:

In the genius of my mind, I decided to try and "Lock" the flywheel in place by using grade 8 bolts threaded into the flywheel bolt holes and letting one rest against the engine stand spider as I undid the crank bolt - didn't work, bolt broke but not only did the bolt break, but it F-d some sort of "sleeve" that looks like its pressed in. There is only one of these sleeves in the end. Forgot to get a pic of it before I left the garage. Any idea on what it is and how to replace it since I smushed the old one?

Don't know what you are talking about. A picture will help. I did something similar. Because the flywheel is too thick to fit the stand, the engine went up without it. I threaded two flywheel bolts back on the holes and jammed a big flat blade screw driver between them trying to use it as leverage to loosen the crank shaft. I bent the lip of the end of the crank. See picture.

http://i21.photobucket.com/albums/b274/yaofengchen/DSC_1652.jpg

I eventually loosened the crank shaft by jamming a piece of wood between the crank shaft and the block to unlock 316 ft-lbs of torque to undo the crank bolt on the flex damper. The bent lip on the end I cut about 1/4" off flush so I can remove the old pilot bearing and install new.

http://i21.photobucket.com/albums/b274/yaofengchen/DSC_1708.jpg

yaofeng
04-18-2006, 01:05 AM
Winfred/Yaofeng - that image with the "TDC" pic doesn't look right. The bentley says the TDC indicator is a "O/T" mark on the wheel... and the gap for missing teeth is usually on the other side of hte CPS... Help!!!

The 0/T mark is on the flex damper. The vertical raised cast mark is on the timing cover. You can line them up exactly to get TDC ignoring the CPS.

Dave M
04-18-2006, 04:09 AM
Yep, the OT is on the damper wheel. I believe the gap is at @9-10 p.m. when the OT mark and cast mark on the timing cover are lined up.

Regarding the alignment dowel, since it is only there to help line up the flywheel properly, I wouldn't worry about it. Just try to get the flywheel on the same holes, if you know what I mean.

Dave M

winfred
04-18-2006, 04:26 AM
that's a bad thing, lucky you were able to trim it



http://i21.photobucket.com/albums/b274/yaofengchen/DSC_1708.jpg

yaofeng
04-18-2006, 04:56 AM
that's a bad thing, lucky you were able to trim it

I had no choice. That's part of the crank shaft. I trimmed it with the Dremal tool not wanting to remove or replace the crank shaft.

winfred
04-18-2006, 05:03 AM
i know that's why it's a bad thing and you were lucky, it would be handy if they were like the old b230 volvo motors were that part pops out and can be replaced


I had no choice. That's part of the crank shaft.

Jon K
04-18-2006, 07:46 AM
Winfred - see in this pic the thing that sticks out...


http://i21.photobucket.com/albums/b274/yaofengchen/DSC_1708.jpg

At about 11 o clock on the crankshaft... its like one of the holes has a sleeve in it? That's what I bent/broke/mutilated. The hole itself is fine.

Bill R.
04-18-2006, 08:05 AM
11111743118, in the etk if you look at the pic of the flywheel you'll see it.






Winfred - see in this pic the thing that sticks out...


http://i21.photobucket.com/albums/b274/yaofengchen/DSC_1708.jpg

At about 11 o clock on the crankshaft... its like one of the holes has a sleeve in it? That's what I bent/broke/mutilated. The hole itself is fine.

yaofeng
04-18-2006, 08:07 AM
The only purpose of the dowel is to locate the flywheel. I'd grind away whatever you bent so the sheet metal dowel doesn't interfere with either the flywheel bolt and the flywheel.

You have no problem in that area. Your problem is the bent timing chain guide pin.

yaofeng
04-18-2006, 08:20 AM
Yaofeng - you're new here but you're very helpful!

I am new and I am also old. My younger son is going to college this summer.

Jon K
04-18-2006, 08:48 AM
Guys, what direction does the crank spin if looking at the engine head on?

Dave M
04-18-2006, 09:08 AM
Clockwise

And forget about the dowel if you don't care to order a new one.

Dave M

Jon K
04-18-2006, 09:18 AM
That would explain why the gap is to the left of the TDC mark... thansk Dave

yaofeng
04-18-2006, 09:34 AM
The crank spins to tighten the fan. So the crank rotates clockwise if you are looking at the engine head on.

Bill R.
04-18-2006, 11:57 AM
built at the factory the flywheel and crank are balanced as a complete assy. The dowel is put there so that you always assemble the flywheel with the lighter or heavier area in the correct location. You'll notice areas on the crank or the flywheel where they have drilled some material out, this is done during the balancing process, on a balanced motor you'll see that the crank, flywheel ,pressure plate, rods, pistons, wrist pins,and harmonic damper have all got areas where material has been added or removed to balance the motor.




Clockwise

And forget about the dowel if you don't care to order a new one.

Dave M

Dave M
04-18-2006, 05:25 PM
built at the factory the flywheel and crank are balanced as a complete assy. The dowel is put there so that you always assemble the flywheel with the lighter or heavier area in the correct location. You'll notice areas on the crank or the flywheel where they have drilled some material out, this is done during the balancing process, on a balanced motor you'll see that the crank, flywheel ,pressure plate, rods, pistons, wrist pins,and harmonic damper have all got areas where material has been added or removed to balance the motor.

I assumed he would be wise enough to line up the associated dowel holes, thereby retaining the postion. My intent was not to advise 'any old' alignment.

Thanks for catching a potential boo boo.

Dave M