spun rod bearing?? - Experienced owners Please enlighten
#20
Those lifters look just like mine, from what I've read in another post about lifters is if they're soft throw them out. The ones that are sticking out are just plain broken. If you take the ones sticking out and slam them on a bench they'll come apart. I think they'll all do that to some degree but the ones sticking out we'll do it pretty easily. Not a lot more help I can give you, do a search on lifters there's a thread about it.
While you have the cam housing off are any of the valves sitting lower than all the others? If so the ones lower are probably bent, ask me how I know. I have 2 exhaust valves that sit lower than all the rest. I'll be pulling the head this weekend but I'm pretty sure they're bent. I'm still not sure how it happened but it did.
While you have the cam housing off are any of the valves sitting lower than all the others? If so the ones lower are probably bent, ask me how I know. I have 2 exhaust valves that sit lower than all the rest. I'll be pulling the head this weekend but I'm pretty sure they're bent. I'm still not sure how it happened but it did.
#21
Three Wheelin'
#22
Race Director
Just so you know... an overrev will not cause a rod bearing failure. I have unfortunaly overrev'ed my race motor a few times. Shooting past 6k to 7k is not a big deal. Shift from 4th at 6000 RPM missing 5th and hitting 3rd... well that is nasty over rev. I got lucky with no damage, but others in similar situtions have experience valve to piston contact resulting in bent valves. The bottom end can take an occasional over-rev. The top end can't take 10000 rpm.
So ... in my experience constant reving to 7-7500k will probably result in bottom end rod bearing failure. Top end can handle it. Occasion rev to 7k or 7500k on acceleration is a non issue. Missed downshift from redline is fine for the bottom end since the valves will probably hit the pistons long before the rod bearings spin.
So ... in my experience constant reving to 7-7500k will probably result in bottom end rod bearing failure. Top end can handle it. Occasion rev to 7k or 7500k on acceleration is a non issue. Missed downshift from redline is fine for the bottom end since the valves will probably hit the pistons long before the rod bearings spin.
#23
Burning Brakes
Join Date: Jul 2006
Location: Aurora, Colorado
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How long did you let it run after you started it up? Mine has a lifter that is obviously getting old, plugged..whatever. Sometimes it makes a racket for 5 min or so until the oil warms up, then it slides off into her normal quiet purr. A good italian tune up follows and she's quiet until the next time I let it sit for to many weeks. When I read your initial post my first thought was lifter noise...but I've been wrong before. :-)
Bill
89 GT-3 track/street
Bill
89 GT-3 track/street