Reinventing Strength: The New Burtz Flywheel Housing
When it comes to Ford’s Model A, every component has a story—some of brilliance, others of compromise. One of the longest-standing weaknesses in the Model A powertrain has been the flywheel housing (A-6395). For decades, owners and restorers alike have battled with cracks, oil leaks, and Ford’s own unsuccessful attempts to solve them. Today, thanks to Terry Burtz of Burtz Block, there’s finally a solution that holds true to the Model A’s original appearance while reengineering its durability from the inside out.
“I wish to thank those who asked me to redesign the Model A Flywheel Housing (A-6395) to solve the cracking problem and eliminate leaks at the rear camshaft bearing,” Terry Burtz said while chuckling. “Nearly all original Model A Flywheel Housings are cracked at the two lower bolt hole locations where the flywheel housing is attached to the cylinder block, and there is often an oil leak from the rear camshaft bearing.”
Why Ford’s Fixes Never Worked
Ford knew this was a problem from the start. Between 1928 and 1931, the flywheel housing went through no fewer than eight revisions. The final revision, in October 1931, introduced external ribs around the bellhousing bolts. But as Burtz explains, this was a cosmetic fix rather than a structural one:
“These ribs did nothing to prevent cracking at the two lower attachment bolts.”
The reason lies in how forces travel through the chassis. Burtz breaks it down:
“The front axle wishbone is in compression during acceleration, braking, hitting a pothole, or hitting a curb. The wishbone loads are transferred to the bellhousing, which pulls rearward on the flywheel housing. This pulling is what causes the flywheel housing to crack at the two lower bolts that attach it to the cylinder block.”
In short, the design placed the wrong kind of stress in the wrong place, and Ford’s incremental fixes never addressed the real issue.
The Burtz Solution
Like his acclaimed Burtz Block and other modern reimaginings, Burtz’s new flywheel housing looks original on the outside but hides crucial engineering changes within. The most important improvement comes down to thickness.
“Where the original Flywheel Housings cracked, all eight revisions to the original design were 0.5 inches thick at the two lower attachment bolts, and the new flywheel housing is 0.875 inches thick,” Burtz explains.
That increase translates to major strength:
- 5x stronger material thickness
- 3x wider reinforcement in critical areas
- 15 times stronger overall compared to the original part
The new design also eliminates the messy oil leak issue.
“The new flywheel housing has an O-ring groove around the rear camshaft bearing and comes with an O-ring and longer attachment bolts. A gasket and shims at the throttle linkage are not needed,” Burtz says.
For fine-point restorers worried about authenticity, Burtz has you covered. “To appear original for cars built before October 1931, the new flywheel housing has internal changes based on Ford’s 7th revision,” he notes. And for those who do need the look of the gasket and shims, the O-ring design still works with them seamlessly.
Compatibility & Confidence
The housing maintains interfaces identical to Ford drawing A-6395, ensuring compatibility with later Model A, Model B, GAZ, and Burtz flywheels, as well as multiple disc setups. That makes it a true drop-in replacement for stock or modified builds.
Continuing the Burtz Legacy
From the revolutionary Burtz Block to precision crankshafts and now this reengineered flywheel housing, the Burtz name has become synonymous with strengthening the Model A without altering its heritage look. Owners gain confidence that their car won’t suffer from age-old weaknesses, and restorers know they can rely on parts that respect the original Ford design.
The new flywheel housing is more than just a part—it’s a long-overdue fix to a 95-year-old problem. For Model A enthusiasts, it means fewer cracks, fewer leaks, and more miles of worry-free touring.