Question for people that know what they're talking about, because I don't - could he run it with some super high ZDDP break in oil to harden the new surface of the worn lobe? Whether or not it's the right way to do it... I have a feeling that 60 years ago they would've just slapped a new lifter in and run it that way... maybe with a magnet in the drain pan.
zddp or "breaking in a cam" do not harden the lobes. When you "break in" a cam and run it at 2000 rpms for 20 minutes. the major reason for the rpms is so the crankshaft will fling oil up onto the cam, It is mostly about lubrication to insure the lifters will rotate properly in their bores . Lifters that do not rotate will wear the cam lobes. In the case of this flathead with the rough, worn lobe, It will just eat the new lifter immediately and fill the engine with more metal filings which will wear everything else out....
Gotcha! For some reason I thought the break in process was about hardening the lobes. I've never built an engine, so I'm not real familiar with it. Thanks for the explanation.
What about leaving the lifter out and pulling the spark plug for that cylinder? You could run a compression check on the other cylinders then see if it will fire . Flathead lifters are lubricated from splash mostly from the valley above. You wouldn't be adding any new metal contamination . First, I think I'd pull the intake and see if the last guy did what you are thinking of doing and left the broken lifter in the pan. You never know.
my 2c, don't try to run it that way as you can do more damage than good, go ahead and pull it apart to check bearings and clearances anyway, if good replace cam and lifter and a new set of gaskets, if bad rebuild it.......
The lifter is definitely still in there, I can see and feel it form underneath. That’s what I’ve decided to do. Just haven’t got to it yet.
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