Knock knock

[Wildcat]

So I have started to drive my 51 more now that the weather is turning and this is probably the most use this car has seen in 20+ years so I am really paranoid about everything and just waiting to burst into a really cool looking ball of fire.  Anyhow, there is a knock of sorts, but it is unlike any knock I have heard before, it only comes out at higher RPMs and load when the engine is warmer, i.e. going up a hill, 50 mph.  If I stop and rev the engine while parked, nothing.  So I guess where I am going with this, is this something that is normal for a Kaiser, or should I be looking into buying some rod bearings?  Possibly detonation?  I really don't feel like blowing a hole in something that can't be replaced.

[Kenn Evans II]

Check your valve adjustments, then check your plugs and wires. you might check the distributor lobes for excessive wear. at high rpms under load it could be a bad plug or wire starting to break down. if your dist. lobes are worn with loss of vacuum pressure you may experience delayed ignition and tracking which could contribute to a knock.

[boatingbill]

This sounds like a classic case of a main bearing knock, which usually has a deep sound to it. When the engine is warm and the oil thins, the knock may be due to low oil pressure or to excessive main bearing wear. This usually occurs under heavy load like going up hill. I would recommend to drop the oil pan and check the crank journals and mail bearings for excessive clearances due to wear. That pounding is a sure sign of serious trouble up ahead if you ignore it.