83 Ford F100 300/4.9L I6; 1k miles and high wear

[PontiacHO]

Those 300 cubic inch Ford six cylinder engines are very good engines. I had an 82 F100 with that engine and a manual 3 speed trans. Pulled a trailer with an International tractor behind. Torque!

 

[psudewd]

It's been great. Had to rebuild it due to cracked rings originally, fairly common problem. The cam certainly shifted the power curve north but it still makes great torque and is plenty fun to drive.

 

[Cujet]

I'd not chase a ghost. If it runs well and there are no signs of trouble, just run it. Having a bearing with a minor score can cause high lead and tin, yet be perfectly serviceable.

The fact that you ran leaded fuel is a big clue to high lead levels. A UOA during the use of leaded fuel might show 2500PPM Pb. It takes quite some time and many oil changes for the numbers to come down to nil.

 

[psudewd]

I'd not chase a ghost. If it runs well and there are no signs of trouble, just run it. Having a bearing with a minor score can cause high lead and tin, yet be perfectly serviceable.

The fact that you ran leaded fuel is a big clue to high lead levels. A UOA during the use of leaded fuel might show 2500PPM Pb. It takes quite some time and many oil changes for the numbers to come down to nil.

Appreciate it. I don't want to chase a ghost either. But if given the chance I would like to fix it preemptive rather than after a catastrophic event. Tough scenario . Sometimes better not knowing I guess.

 

[Cujet]

Those numbers are so low, I don't think there we are looking at impending doom. I've seen 225PPM Pb from bearings that still were in acceptable shape! And, I really do think the Pb is from the prior fuel use.

 

[wpod]

I had a 79 F150 with the 6 cyl and 3 on the tree it was an unleaded engine.

 

[PontiacHO]

The original tear down revealed cracked rings? Due to overheating, spark knock (timing -clogged egr), excessive piston to cylinder wall clearance? Hopefully you corrected any of those possible causes for the cracked rings during rebuild. Again, that’s a nice engine that should give many years of service.

 

[psudewd]

The original tear down revealed cracked rings? Due to overheating, spark knock (timing -clogged egr), excessive piston to cylinder wall clearance? Hopefully you corrected any of those possible causes for the cracked rings during rebuild. Again, that’s a nice engine that should give many years of service.

Causes.... likely some combo of all the above. Was never majorly overheated but had gotten hot. EGR on anything from the 80s was questionable. The outer ring in the balancers had a habit of slipping thus causing incorrect timing when it was adjusted. Throttle shaft wear in the carb causing vacuum leaks. It had nearly 106K on it when i finally tore it down. And yes everything was gone through. New balancer (confirmed tdc on it) new distributor new cooling system. It has been trouble free since the rebuild other than this UOA result.

 

[PontiacHO]

You’re good to go then. I wouldn’t worry much about an oil analysis. I’ve seen too many that are woefully inaccurate. Using the oil your using and maintaining it the way you have, you will be tired of it before it’s worn out.