So I ran into this problem and I can't figure out what is going on, hoping someone can give some insight.
I bought a M20B25 motor with a bad head, bought a refurbished 885 head. When I got the refurbished head I was able to turn the cam (off the block) using a socket wrench on the cam pulley bolt. I set the rocker gaps off the block, installed the head, and then tried to get the cam to top dead center by using a socket wrench on the cam pulley bolt again and it wouldn't move. I know this is an interference motor and I made sure that the pistons were down on the cylinders that the valves were open in. I also put a wrench on the crank and rotated it slowly in both directions until I felt it just come into contact with a valve, then split the difference between the two contact positions and tried moving the cam again, lots of resistance and no movement.
I followed the head bolt tightening sequence shown here, http://www.rtsauto.com/the-art-of-bolt-tightening/
22 ft.lb, 90degrees, 90degrees, in order
I decided to pull the head back off and check the head and block for flatness and could not get a .004" feeler gauge under my straight edge anywhere on either surface.
This whole thing has left me, and everyone I've asked about it confused, and I was hoping someone here might have some insight I have overlooked. Let me know your hypotheses and ask any questions that I may have not addressed.
Thanks in advance.
Sent from my SM-G960U using Tapatalk
I bought a M20B25 motor with a bad head, bought a refurbished 885 head. When I got the refurbished head I was able to turn the cam (off the block) using a socket wrench on the cam pulley bolt. I set the rocker gaps off the block, installed the head, and then tried to get the cam to top dead center by using a socket wrench on the cam pulley bolt again and it wouldn't move. I know this is an interference motor and I made sure that the pistons were down on the cylinders that the valves were open in. I also put a wrench on the crank and rotated it slowly in both directions until I felt it just come into contact with a valve, then split the difference between the two contact positions and tried moving the cam again, lots of resistance and no movement.
I followed the head bolt tightening sequence shown here, http://www.rtsauto.com/the-art-of-bolt-tightening/
22 ft.lb, 90degrees, 90degrees, in order
I decided to pull the head back off and check the head and block for flatness and could not get a .004" feeler gauge under my straight edge anywhere on either surface.
This whole thing has left me, and everyone I've asked about it confused, and I was hoping someone here might have some insight I have overlooked. Let me know your hypotheses and ask any questions that I may have not addressed.
Thanks in advance.
Sent from my SM-G960U using Tapatalk
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