We thought we were making solid progress on the Mustang build for the 2026 season. Good timing though—the first points race got rained out, because this thing was not ready yet.

Due to my recovery from brain surgery and ongoing trigeminal neuralgia, I haven’t been able to physically work on the car the way I normally would. So the Mustang was moved to my brother-in-law’s shop, where he stepped in to help carry the build forward.

This phase focused on a major performance upgrade using AFR cylinder heads, paired with a new camshaft, lifters, pushrods, and supporting valvetrain components. The goal was simple: modernize airflow, improve efficiency, and bring the combination closer to a consistent, competitive bracket setup.

Once assembled, the engine fired immediately and sounded strong and clean. Initial test drive feedback was very positive—better throttle response, improved power delivery, and a noticeable increase in overall performance.

On the second outing, things escalated quickly. My brother-in-law brought his 16-year-old son along—an accomplished young racer with 24 Wallys already to his name. Under load, the car immediately went sideways, lighting the 275 drag radials clean off and driving both of them hard into the seat. The car was instantly engulfed in smoke.

But not all of it was tire smoke.

Oil began pushing out of the valve covers.

That’s when we knew we had a bottom-end issue.

Diagnosis: Blow-By Under Load

This engine was originally assembled by me over 25 years ago. At the time, it ran strong with its original configuration and later responded well to higher compression setups. However, the car sat for an extended period of time, and over that time the ring seal degraded.

With the addition of the AFR heads improving airflow and efficiency, the engine was now moving enough air to expose the weakest point in the system: the aging bottom end and ring seal.

In short—the top end upgrade did its job perfectly. It improved performance enough to reveal what needed attention below.

And as things always go, the weakest link was now found! In this case, rings.

Corrective Action: Summit Racing Bottom-End Refresh

Immediately after diagnosis, we sourced a full bottom-end rebuild kit through Summit Racing.

The plan moving forward is straightforward and aggressive given the race schedule:

Engine removal
Cylinder inspection and light hone
New rings and main/rod bearings
Full bottom-end refresh and reassembly
Rapid turnaround to stay within race window

This approach allows us to retain the AFR top-end gains while restoring full sealing integrity and reliability under load.

Performance Outlook

Once refreshed, the combination is expected to:

Return to consistent low 12-second performance, possibly very high 11’s
Deliver improved airflow efficiency from AFR heads
Provide a stronger, more reliable bottom end under repeated passes
Serve as a solid foundation for a future stroker upgrade

We’re also evaluating chassis safety upgrades, including whether a cage will be required as performance continues to improve. The current goal is still to maintain a mostly stock-interior, sleeper-style appearance that fits the personality of the car. Wife thinks she wants to go faster, but doesn’t want to sacrifice her stock interior look.

Built, Tested, Improved

This is real-world development—not theory.

The AFR heads delivered immediate airflow and performance gains. The Summit Racing-supported rebuild is now addressing the next weak link revealed under real testing conditions. This is exactly how performance combinations evolve: test, break, analyze, improve.

It’s not always clean, and it’s not always planned, it’s not always pretty—but it’s how progress actually happens.

Closing

We’re in the middle of a rebuild cycle now, but the direction is clear.

Build it. Test it. Break it. Fix it. Make it better.

Once this refresh is complete, we’ll be back on track with a stronger, more efficient Mustang—and a much better understanding of what the combination can really do.

Big thanks to the companies and parts that make real-world racing possible:

AFR Cylinder Heads – airflow and performance gains that immediately changed the character of the engine
Summit Racing – rapid support for bottom-end rebuild components under time pressure

More updates coming as the rebuild progresses and we head back toward race-ready form.