Oh my gosh! No filter in my H!

I have no idea how long it was run without a filter I just bought it last year.

How much damage might this have done?

As others have said, if you still have good oil pressure and don’t hear any knocking from the engine, just change the oil and put in a new filter. The cleaner the oil the better off the engine will be.

Now what damage might have been done is dirt or carbon pieces may have passed through the bearings on the crankshaft and put grooves in them. Normally, the bearing is soft enough to absorb the foreign material and the crankshaft will remain unharmed. However if the piece is large enough, it will damage the crank. The impurities could also have gone through the camshaft bearings and done similar damage as on the crankshaft bearings. Worst case is that something would have lodged between the piston and sleeve and scored them. There may also have been damage done to the oil pump gears if big enough pieces of crud went through the oil pump.

I don’t want to alarm you but this is what MIGHT have happened, not what did happen.

Tim