Rotated Cam wrong way..help

mikey911 · 01-08-2006, 02:10 PM

I am rebuilding a 1983 3.0 using Wayne's book. I was almost at the finish line as I was setting the timing chains. I was attempting to get the left CAM with the 930 at the top on the left side using the CAM bar...unfortunately I was going clockwise...I did not realize it turned the other way. I then attempted to use the flywheel to set the TDC at the Z1 mark when I encountered strong reisistance and then a loud clicking sound came from the left side...sounded like it came from the case. Now I cannot turn the motor at all from the flywheel. Any help anyone could provide as to what I did and is this is the end of this motor.
Thanks

Mike
1974 911 coupe

CliffBrown · 01-08-2006, 02:33 PM

Mike

Have you installed any of the rockers?

mikey911 · 01-08-2006, 03:08 PM

Yes the rocker arms are installed. I actually did not take apart. I had one broken head stud so I disassembled down to case...did not ahve the funds for a full rebuild but the motor only had 23000 original miles. I replaced the rings on both sides and was in the process of setting the timing when I screwed up. Any ideas would be appreciated

Thanks

Mike

CliffBrown · 01-08-2006, 07:35 PM

Mike

Step one remove the rockers or at least loosen the adjusting screws completely to eliminate any possibility that a piston has run-up against a valve or two.

mikey911 · 01-09-2006, 04:52 AM

Thanks for the advice..I will try that and get back

Mike

Rot 911 · 01-09-2006, 06:37 AM

I don't think you could have done any serious damage just by turning by hand. Like you have been advised I would loosen ALL of the rockers completely to get the valves to back off.

1972_911T · 01-11-2006, 12:08 AM

Do you have the tensioners installed if not the clik you heard could have been the cam springing back under the load of the valve springs, this can happen if there is slack in the chain, this could have caused valve to piston contact preventing the engine from turning as you described. has its only happening under the spring load its unlikly to have done any damage, I did the exact same thing a week or so ago, I forgot to G clamp one of the chains during timing. The hard bit is trying to get the cam back into the right position to alow the engine to turn again. If this is whats happend to you rather than trying to turn the engine try rotating the cam back the opasite way to put the slack back into the tensioner side of the chain this may move the valve enough for you to start the timing process again.

Steve

mikey911 · 01-11-2006, 05:52 AM

Thanks...that sounds like exactly what happened. I will try again. Can you use the actual tensioners to maintain the timing chain in stead of the special tool or a clamp?

1972_911T · 01-11-2006, 07:02 AM

Not to do the timing as they wount put enough tension on the chain, what your trying to match is the tension on the chain when the engine is running rotating the cam, the tensioners really just serve to take out the slack. However if you only have one clamp you can installl the tensioner for the otherside to what your working on to prevent that from slipping.

Steve

mikey911 · 01-11-2006, 07:36 AM

Thanks for help. Another question, If I did not take the cam tower off of the heads do I still need to check the timing and can you use any type od dial guage or do you need the z bracket sold by pelican?
Thanks

Mike

1972_911T · 01-11-2006, 07:44 AM

If you had not removed any of the chain setup ie, the sprokets or tensioners then no you wouldnt have to check or adjust the timing if you have removed any of this then you will need to reset it. Theoretically if you just remove the tensioner then it shouldnt have changed but the problem is you carnt be sure that the chain hasnt skipped a link or two if you have rotated the engine with slack in the chain. in this case I think it would be safest to recheck it just incase as any errors here could seriously damage your valves/rockers and/or pistons. Most standard dial gauges will work for checking the timing however the z block from pelican is almost a must as it is specifically designed to clamp the dial gauge to the porsche cam towers.

Steve

mikey911 · 01-11-2006, 08:17 AM

Steve,

Appreciate the help. I just ordered the tool as I have moved the chain. Seems like a tricky process setting the timing...we will soon find out. Again thanks for the advice.

Mike