M20 problem

[4bimmers]

Before I ask this question I want to qualify myself. I am presently in the midst of my first M20 engine rebuild and I am absolutely learning as I go. I am sure by the time this engine is back together I will have aged several years.
Now for the problem...
I am trying to put the crank bolt back on after replacing the seals in the front cover. I can not get the TDC marks to line up and as I turn the crank to line up the marks and tighten the bolt the crank will only rotate 180 deg. and then it stops (I assume the pistons are contacting the valves?) See from the photo the mark on the cover and the mark on the sprocket is around at approx. 8:00.

When I initially removed the crank bolt and crank sprocket I only rotated the crank less than 180 and I assumed that all I had to do was rotate it back to TDC. Something obviously has gone awry but how do I insure that the crank and cam are back in time? (The cam shaft has not moved any during this time)

[nando]

wait, what are you using the hold the crank stationary? you aren't just waiting for it to stop when the pistons hit the valves, are you?

[4bimmers]

re

When I removed the crank bolt, the crank turned a number of degrees around and as I was reattaching the crank bolt I was trying to rotate the crank back around to the TDC position. Do you think I am going to have to remove the head and inspect the valves?

[Super Eurobeat]

well you should have put the belt on the the car so you cant screw this up (timing belt).
The valves should stop whent he pistons touch them but will nick them.
You dont have to take the head off.
But if you have to, take off the downpile to manifold bolts, hoses, injectors, etc...and pull it off, then set the crank at the number one cylinder at TDC which is the line on the cover lined up with the crank notch...
then line up the camshaft sprocket alignment mark to the line that is on the head itself...its easy.

If there is a mechanic near you, leave your credit card and drivers licence and borrow the tool to hold the crank while tightening the nut to 302 foot pounds...there is a topic someone made a day or two ago on roadfly.com's "E30" message board.

If you need help, call me at 209-333-1317
~~Matt Hernandez

[4bimmers]

Duhhh!

Well, at the risk of exposing my rather persistent ignorance, the problem is fixed. Take a look at the picture and see if you can tell what is wrong. The *&?!@%# sprocket is on backwards. No wonder the timing was off 180 degrees. Thanks to my brother who diagnosed the problem over the phone. Oh well, on to other challenges.

[nando]

hah! you're right, it is!