I seldom will disagree even a little with Engatwork but I agree with Larry here, the hb is very very tricky to install and many a good crank has been ruined by improper installation, necessitating pulling the engine down to replace the crank.

At the oil level of consumption you mention I would not touch it but just add oil and put something under the engine to catch drips when it sits. Are you using synthetic oil by chance? Old fashoned dino oil might be the best choice if you are.

This being a 115 it is not turbo and this part of the motor is essentially the same as the later 616 and 617 motors.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.