Finding tdc

[fiftytakedowns]

Hey,

I have a JB racing flywheel so I dont have the TDC pin to hold it in place. how can I double check that the cams are EXACTLY in line with TDC of engine? I just used a probe to measure the top of the  combustion stroke and set it to that.

Is there a certain notch on the pulley or soemthign, because there is no mark on the front timing case.

[DesktopDave]

There are square blocks cast on the rear of the cam.  The top of each is cam block is machined flat.  When #1 cylinder is at the top of its stroke and the machined tops of the cam blocks are even with the cylinder head surface you're at TDC.  The home-made cam tool is two adjustable wrenches on the sides of those blocks held together with a clamp or vice-grips.

http://img96.imageshack.us/img96/7196/camlockingtool.jpg

Do you have the e-copy of the Bentley?  Here's the e30 copy:
http://rs419.rapidshare.com/files/36...30_bentley.rar (pass is "bmw").       
Here's the e36 one:
http://www.megaupload.com/?d=8Z3328SZ
You'll need them both...the e36 Bentley has the M42 info that's missing in the e30 one.

[fiftytakedowns]

There are square blocks cast on the rear of the cam.  The top of each is cam block is machined flat.  When #1 cylinder is at the top of its stroke and the machined tops of the cam blocks are even with the cylinder head surface you're at TDC.  The home-made cam tool is two adjustable wrenches on the sides of those blocks held together with a clamp or vice-grips.

http://img96.imageshack.us/img96/7196/camlockingtool.jpg

Do you have the e-copy of the Bentley?  Here's the e30 copy:
http://rs419.rapidshare.com/files/36...30_bentley.rar (pass is "bmw").       
Here's the e36 one:
http://www.megaupload.com/?d=8Z3328SZ
You'll need them both...the e36 Bentley has the M42 info that's missing in the e30 one.

Well I did the cam timing with the cyl #1, but I am not 100% sure I got the EXACT location of the piston correctly, as you can find teh top of the stroke for the piston,bt you can move the wrench on the crank bolt a little bit before it starts moving back down  (thats what the cyl probe shows at least.  the reason I am concerned is because of the misfiring issue I am having from 2k-3k rpm that happens sort of randomly or sometimes when up or downshifting into that RPM range. I am trying to rule out cam synchronizing with the cam position sensor as a possibility.

[MLM]

The way to find TDC accuratly is:
Find tdc roughly (within 15 degrees is good enough). Put the probe in and turn the engine before tdc by say 45 degrees and mark the depth of the probe. Also mark the pulley inline with a point on the block (like the factory tdc point) then turn the engine so the probe rises through tdc then starts to fall again. Keep turning till the probe is at the same depth as it was before using the marks on the probe. Mark the crank pully at the same reference point.

Now lookin at the two marks on the pulley TDC will be exactly between the two marks at your reference point

[DesktopDave]

Never thought about doing it that way.  That's a good tip.  I'll bet your geometry teacher would be so proud!

[nomade30]

I found the easiest way is just taking out cylinder one spark plug, setting a screw driver in there and when it reaches the highest point to and leave it there.

[dakon]

And to think i just spent 160$ on a cam lock from pelican today.....:rolleyes:

[rjcaptsean]

Can Ya'll say "Redneck"?  I knew ya could...    

[Slick92GS-R]

^^^  i would trust this more than those damn wrenches & vise grips..

BTW, who says M42'ers are not on the cutting edge of engineering ?

[nomade30]

Me.  They are old, designed over 20 years ago.  Cutting edge is like 5 years max.