Wallic did have one asset: Bart Grange, a friend with an intact McCulloch. He disassembled that blower and measured every critical tolerance. Then he and Hamilton rebuilt his blower to those specs.
The absence of service parts didn’t seem to interfere: the consumable items consist of universal shaft seals that Wallic bought from his local bearing house and paper gaskets that he made from magazine pages and covers. He made only one part, a thrust bearing, which he reproduced with a brass washer. His were good but the plain bearings would be easy to reproduce by just about any machine shop. Beyond that there are no other wear parts to replace beyond gears, the rotor, shafts, and the case castings. And even if those parts were still available it would still probably make better economic sense to find a better blower to rebuild rather than try to buy replacement parts.
We contributed another asset to the knowledge pool: good pal and Early V-8 Club member Alan Darr. A collector of outstanding note (see his Gilmore collection in the first Street Rodder Premium), he snapped up the few pieces of rare McCulloch literature that came his way over the years. Among them are a schematic and a series of technical sheets that show part numbers for the ’39 Ford blower which is internally identical to Wallic’s ’39 Mercury blower.
These sheets don’t reveal assembly instructions but they do give us pause to wonder if the blower Wallic referenced matches McCulloch’s specifications. For one, the schematic shows shims (gaskets) in places where there were none in the reference blower. For another, the thickness of a number of gaskets in the reference blower differs from the thickness that McCulloch’s literature calls out. That McCulloch specified 0.002- and 0.003-inch-thick gaskets indicates that it was concerned with precision down to 0.001-inch. That’s critical knowledge as McCulloch used gaskets as shims to set critical tolerances just as Ford did with its early rear axles.
It could very well be that the reference blower is still right at (or at least close to) McCulloch spec. But it could just as easily be out of whack. So understand that the information we’re going to dispense here isn’t gospel. It’s just the best we have.
But to be fair, the best we have seems to work so far. Wallic has since installed his blower on the engine in his roadster. Though he hasn’t had the opportunity to flog it for miles on end he says he definitely feels a bit more power and so far neither the blower nor the engine has complained. Fingers crossed, this could be it. At least we’re a little closer.
The information Darr’s literature reveals would take too much space to address properly in one installment. So for that reason we’re going to divide the story into tentatively two parts: this one to show the basic rebuild and another to shed some light on the way the literature suggests these parts install on the engine.
We say tentatively because we’re hoping that this story rattles loose some more vital information that could lead to additional installments. In fact we’re going to make the same challenge to you that Wallic made to us: We bet you can’t turn up any more information. We dare you to prove us wrong, if only so we can expand the knowledge.
So have at it: show us some literature that shows us how right or wrong we really got it. Until then, take a rare look inside a rare specimen.
Special thanks to Frank Wallic, firstname.lastname@example.org.