Re: Aluminum block cleaning Question

Posted by Tim Cole On 2016/2/8 16:07:46

Old zinc and especially cadmium plating will weather, flake off, and act like paint.

Besides that I have never seen any indication, or seen a reference - eg Turnquist - mention crankcases being painted. Turnquist states unequivocally they were not painted. If they were then that would have been the practice for the past 60 years. I have factory photos indicating they were not painted (transmission painted silver motor not painted). Cast iron rocker follower covers were painted, but aluminum ones weren't. You can be sure that if they were supposed to be painted Hirsch would sell it.

As far as painting them goes, the right tone of base coat with clear coat actually looks pretty darn good. I wouldn't deduct for that even if someone was hooting about it on the field.

The glyptol thing is just a religion with no engineering justification. Buick painted the inside of their motors.

I did find one case where a Packard owner had a dealer remove the motor and polish the crankcase to a mirror finish.

As for cleaning, I used to use a steam jenny (maybe you can rent one), elbow grease, and soft steel wool on the outside only. The only oil passages in the pre-34 motors is the rocker follower and camshaft feed from the rear main. However the camshaft has a plug that can be removed for cleaning the internal gallery. Later motors have feeds for pressure regulation.