Timing and compression

[04EddieBauer1203]

I pulled my engine because the timing cassettes where shot.

I have meticulously replaced them... set 1st cylinder to top dead center, made sure the balancer was set properly, as well, properly set both cams -- both with the 6488 tool set, but also visually confirming their positions -- but I am hesitant to put the engine back into the vehicle because when I turn the crankshaft clockwise by hand with a bar on the harmonic balancer bolt (with spark plugs installed) I do not get any sense of any compression.

I can even watch the valves opening an closing from the intake... I have even removed the cams and blew into each exaust and intake port by mouth and my breath goes no where (full resistance, no noticed air leakage)... I can't imagine that by cranking it by hand that I would not feel some significant resistance from compression. Oh, and I tried this with cams installed and turned the crankshaft to check each piston airflow from exaust to spark plug port: I'd blow into the exaust port and feel my breath come out of the spark plug port, then stick my finger in the spark plug port, and my breath would hault and I would not notice air leakage. So the piston rings seem fine as well.

Does anyone know if this feeling of no compression is normal, before I take most of a day to reinstall this engine?

 

[imp]

I pulled my engine because the timing cassettes where shot.

I have meticulously replaced them... set 1st cylinder to top dead center, made sure the balancer was set properly, as well, properly set both cams -- both with the 6488 tool set, but also visually confirming their positions -- but I am hesitant to put the engine back into the vehicle because when I turn the crankshaft clockwise by hand with a bar on the harmonic balancer bolt (with spark plugs installed) I do not get any sense of any compression.

I can even watch the valves opening an closing from the intake... I have even removed the cams and blew into each exaust and intake port by mouth and my breath goes no where (full resistance, no noticed air leakage)... I can't imagine that by cranking it by hand that I would not feel some significant resistance from compression. Oh, and I tried this with cams installed and turned the crankshaft to check each piston airflow from exaust to spark plug port: I'd blow into the exaust port and feel my breath come out of the spark plug port, then stick my finger in the spark plug port, and my breath would hault and I would not notice air leakage. So the piston rings seem fine as well.

Does anyone know if this feeling of no compression is normal, before I take most of a day to reinstall this engine?

You got pretty good lungs! To feel compression turning the crank real slow is doubtful. Search the valve timing specs, you can guess reasonably close as to crankshaft angle by marking the damper with chalk in 4 places, 90 degrees apart. Turn crank while watching #1's valves. Valve cover must be off, obviously. Intake should begin to open some small amount before top center. It should almost be closed by the time it gets to bottom center. If the valve timing is 'way out of whack, you'll surely see it when the valves don't open/close close to spec. Just a thought. imp

 

[04EddieBauer1203]

I found out that, contrary to many websites, this engine is in fact an interference engine. All the exaust valves were damaged when the timing chain tensioner from the crank shaft to the jack shaft broke.

 

[imp]

I found out that, contrary to many websites, this engine is in fact an interference engine. All the exaust valves were damaged when the timing chain tensioner from the crank shaft to the jack shaft broke.

Very interesting! How was the damage repaired? New valves? New heads? How were the piston crowns? Curious, were you present when the thing let loose? imp