911SC Valve Adjustment Problems
#16
Rennlist Member
Suggestion: Why not read the other posts in a thread before chiming in?
#17
Team Owner
This is interesting, better wait for Pete or Steve on this one. Did you have to adjust any of them very much ? if you had to adjust any of them more than a full turn I would be suspicious. I would think if you really screwed it up you could have adjusted a valve so far in it is hitting a piston but that would be remote.
If you are suspecting this I would satrt all over , see if at the point it stops do oyu here metal on metal , or even try backing them ALL off and strting from scratch.
Sounds like it could be something else though.
If you are suspecting this I would satrt all over , see if at the point it stops do oyu here metal on metal , or even try backing them ALL off and strting from scratch.
Sounds like it could be something else though.
#18
Racer
Your initial post states after this you tried to start and the engine turned over. Did it do this with any resistance...did it stop suddenly? I think you may want to start over with the adjustment but I'm not sure you shouldn't also back the valves out to minimize the chance of a valve hitting a piston if for some reason the adjustment got mixed up. BTW, are you using the "backside" method or the regular one? This won't solve your problem but I do find the backside method easier.
One question I'd have for the board in general is how do you confirm you are at the correct TDC on an engine if, as in this case, you may have gotten all the valves adjusted at the wrong point? I realize the notch still needs to line up with the case line but how do you know which side of the 720 degress of rotation are you on, if that makes sense. The point being that the #1 piston is at TDC twice in any full cycle, how can you tell if you are at the "starting point", once things are out of whack?
One question I'd have for the board in general is how do you confirm you are at the correct TDC on an engine if, as in this case, you may have gotten all the valves adjusted at the wrong point? I realize the notch still needs to line up with the case line but how do you know which side of the 720 degress of rotation are you on, if that makes sense. The point being that the #1 piston is at TDC twice in any full cycle, how can you tell if you are at the "starting point", once things are out of whack?
#19
Rennlist Member
At TDC I "shake" both rockers on #1 to make sure neither of the valves is under any pressure from the cam. With .004" of gap, there is ever so slight of a wiggle. Not scientific, but it works for me.
#20
Team Owner
Also if you are at top dead centre the rotor will line up with the notch in the distributor housing for cylinder number one. but i also do the wiggle check as an additional check.
#21
Intermediate
Join Date: Nov 2007
Location: Orleans, MA
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Do you have A/C compressor installed? If not, if you can get a wrench on the crank pulley nut, see if you can get any movement at all. If so, then it points to upper end seizure.
#22
Team Owner
One piece of advice i can give. Do NOT get frustrated, if the worse happend and something broke, have it towed or tear it down. DO NOT try to start it or ref on it , The bills will only escalate.
#23
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Join Date: Jul 2003
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There was a thread on Pelican about an engine not turning. It was mentioned that big blocks of carbon can detach from the heads and fall in the cylinder.
Here is the thread : http://forums.pelicanparts.com/showthread.php?t=436341
I think the engine would still move on a slight CCW, but who knows...
If something pushes on one side of the piston, it should create a torque that kinda blocks the piston, right ?
By looking at the distributor and flywheel, can we know which piston is at the top ? Chances are there's something wrong on that cylinder.
Here is the thread : http://forums.pelicanparts.com/showthread.php?t=436341
I think the engine would still move on a slight CCW, but who knows...
If something pushes on one side of the piston, it should create a torque that kinda blocks the piston, right ?
By looking at the distributor and flywheel, can we know which piston is at the top ? Chances are there's something wrong on that cylinder.