The amount of gases coming out of the breather pipe (assuming that is being shown in the underneath view) indicates a (new) top end problem, assuming the engine was ok beforehand, the new issue could be just a blown head gasket, if so, that could also explain the oil burning off the cylinder head area, as either oil is leaking onto the fins from the pushrod tunnel/tube as a result of the head gasket leak, or a rocker box gasket is leaking onto the fins caused by the head gasket increasing the crank case pressure.
Engine sounds ok, but you should know more when the head is off.
You might be able to verify a blown head gasket by slowly turning the engine over by hand and listening for hissing noises!
You MIGHT be lucky if you have a solid copper head gasket and you have the option of trying to fix it by simply re torquing the head bolts but more likely a top end strip down is needed.