Cont

Cont. from page 4

with cast iron rod while still at the elevated temperature, while the block is still in the oven. When done correctly, the weld is stronger than the parent metal. A typical welded repair, requiring a sleeve, runs $400-$500. Obviously this isn't a home-repair situation, but it's routine work in the heavy equipment industry where castings costs thousands of dollars.

CRANKSHAFT

Other than a cursory visual inspection and measuring the journals, there's little you can do with the crankshaft other than ensure that it will be thoroughly cleaned by removing the Welch plugs from the cheeks. By doing this you can be certain that hardened, decades-old sludge will actually be removed from the drill- ways when the crankshaft is hot- tanked rather than just loosened enough to enter the oil stream once the fresh engine has been put back together and run. The crankshaft - or more specifically a stroked crankshaft - is the single biggest improvement you can make to a flathead, Dave says. Put a 1/2-inch stroker crank in it, and "It's really going to have torque, it really turns into a tractor, and that's what it likes.” He continues, “It doesn't breathe (very well) so let's make it into a tractor!" Leave the bore stock, he advises. "Bore it 30-40 over, whatever it needs to clean it up, and the cylinder walls won't be moving around. The thinner the

Pressure testing (above)

Sonic testing below

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Flathead Stroker Kits and More in Store For the Future

Dave Tatom Custom Engines and SCAT Engineering are close to releasing a new cast steel stroker crankshaft, to be offered in 4- , 4- 1/8- , and 4-1/4-inch stroke, that will use standard 8BA rods and insert bearings, unlike the traditional method of offset grinding a stock crankshaft which requires the use of old-tech 21A rods with expensive floating bearings. Target price for the new crankshaft is $895, in any stroke. Tatom is working on a steel billet rod, to be made for them by Crower, that utilizes the bearings from the 215 cid GM aluminum V8. This promises to be the salvation of all those old 30- and 40-thou' undersize Mercury cranks that can now be off-set-ground to a 2-inch standard. The billet connecting rod is an interim step in a larger plan that will eventually produce new 8BA rods. Finally, a new block is in the feasibility study phase of planning - the "talking stages" as Dave calls it. It will be a high-quality, high- nickel-content iron casting, outwardly the same as a Ford/Mercury block but with some important refinements, such as steel main- bearing caps to replace the cast iron caps, a reinforced center web (". . . a weak point in the original block," says Dave), increased deck thickness to 1/2- inch “. . . so a guy can put a blower on it without pulling the studs out of the motor like they do," he adds. "You can't run much over four or five pounds of boost on a flathead and make it live." The potential here is pretty seductive as Dave explains that he's built blower motors with as much as 15 psi boost that produce 500 hp on alcohol but are short-lived, given the shortcomings of the stock block. "Ten minutes of that (level of boost) and it's junk," he says. -MB