WOT problem list item #4

[cj7ole]

1989 Mercruiser 5.7 Comp Ski engine w/ 700 hours. QJet carb, Complete head and valve job 2 years ago after an overheat. I added the overheat alarm since. I lost 800 rpms after the rebuild. Changed distributor to the Delco EST, no change. Main filter was changed and the carb filter was clean. Checked the oil level and it was very high, I had to remove 2 1/4 quarts to get below the full level on the dipstick. I had put 5 quarts in without changing the filter and must not have sucked all of the previous oil out the dipstick tube. My bad. No change in WOT speed after removing the excess oil. Anyway in going through the WOT problem checklist, I ran across:

4. Crankcase oil volume, high oil level can cause aerated oil and lifter collapse

So, is a lifter collapse a temporary thing until the oil level returns to normal, or do they stay collapsed?

 

[HT32BSX115]

Re: WOT problem list item #4

Howdy,


Well sort of. Once the "scrubbing bubbles" are gone the lifters would presumably pump right back up.

I should add another one to the list though.

My previously installed OMC 460 wouldn't make max RPM and I found several cam lobes were almost FLAT!!

The valves associated with those cam lobes were barely opening at all! That would absolutely limit RPM and power!