Get Better Head Gasket Sealing For Your Nitrous Or Boosted Application

The Ultimate ‘Ring of Fire’

Implementing new technology in head gasket retention with BTR Performance’s Bill Trovato

Written By Chad Stephens
Photography Courtesy of BTR Performance

With the strenuous demands on our race engines today, one of the key secrets to horsepower production and consistent performance still comes down to one of the most important basic concepts: using cylinder pressures and the forces of combustion to our advantage. Doing so effectively requires one to keep their cylinder heads as firmly clamped and sealed up against the engine block (without creating any distortion) to eliminate the most common mode of head gasket failure, which is a ‘breach’ or blow out between cylinders.

In layman’s terms, the forces created on the combustion stroke are responsible for the ‘push’ on the piston, which drives the connecting rod downward, therefore rotating the crankshaft, creating torque. Increasing that available cylinder pressure not only turns the crank harder (by adding torque), but more importantly does so quicker and faster (by adding horsepower). In the game of an acceleration contest (like drag racing), this wins races! This is the one of the largest contributing factors to running at the front of the pack. They say, ‘whatever turns your crank’ and in almost all cases for us racers, the answer is the most cylinder pressure possible please!

These new rings can make a big difference in your engine program. The flame hoops on the right are substantially taller than traditional O-ring wire on the left. The square edge combined with the extra height securely locks the rings into the accompanying grooves milled into the cylinder heads, while providing plenty of ring height to protrude into the gaskets and accompanying rings in the engine block.

Taking advantage of this phenomena boils down to a key factor of how much resistance your head gasket sealing system offers against the pressures it’s subjected to without failing. Well, to answer this question, we went straight to the experts.

Bill Trovato of BTR Performance located in Rochester, New York, a well-known engine builder and successful heads-up racer, has been utilizing a new advanced cylinder sealing technology known as ‘top fuel’ or ‘flame’ hoops, and he has been kind enough to share his experience with these to the readers of here.

Supplying these ‘hoops’ to Trovato is Visner Engine Development (VED), a well-known entity in engine innovation. Trovato, whom with other racers like Ultra Street/ Xtreme Street racer Mike Thompson, are pushing this technology forward and further every chance they get. Because Trovato’s 5th-Gen Camaro relies on copious amounts of nitrous to compete with the best in NMCA Xtreme Street, the more he can apply successfully, the better the odds he will end up in the Winner’s Circle.

To accomplish this. he has been testing and perfecting the application of this distinctive O-ring design. Its uniqueness starts with a square profile on the bottom (versus the full round profile of a traditional O-Ring) which is installed in a relatively deep receiver groove located in the cylinder head.

BTR Performance’s Bill Trovato prefers to use Clark copper gaskets in his engine combination due to their “dead soft” nature and ability to conform to the rings.

The other side of the ‘hoop’ retains the proven half-circle design that protrudes noticeably outwards, which allows them to bite deep into the copper head gaskets. This essentially sandwiches the gasket into the square grooves cut into the block’s deck surface for an optimal sealing system. Another critical features is having a one-piece ‘continuous’ design where there is no gap along its sealing path, (unlike a conventional O-ring), which leaves one less potential weak spot for a failure.

The rings are machined and constructed from stainless steel and sell for around $30 each. Although considered costly to some, the consensus is if they do the job, then they’re more than worth the price, particularly for those seriously pushing the limit of cylinder pressure in the quest for performance.

Regarding installation, Trovato notes that, “some will use a hand fixture, which I don’t agree that this will do the best job,” as anything involving sealing, precision, and accuracy pays dividends. His recommendation is to perform this installation on a CNC machine, located off the cylinder dowels and bore spacing.

The rings measure .040-inch wide x .080-inch tall, and the groove is machined .060-inch deep. This not only anchors the ring firmly inside the casting, but also leaves it protruding out .020-.022-inch, which is nearly double the standard .012-inch that a conventional .040-inch O-ring offers.

On the block side, a receiver groove is machined .020-inch deep x .050-inch wide, giving plenty of seating area for the gasket to impregnate or ‘shove’ itself in for an optimum seal. In a nutshell, if you want to contain the incredible amount of combustion gasses and pressures, you need to build a solid fortress to withhold them. The above process and dimensions, combined with precision machine work, ensures this is indeed the case.

Trovato also mentions that a breach (failure) almost always happens between cylinders, even with traditional O-rings. Bigger bore space engines don’t have as much of an issue, but the engines with tight tolerances between cylinders increases the likelihood of leakage in between them, resulting in a failed gasket. He also noted that the gap between rings is essential to keeping them alive—we don’t want them butted up against each other, as that can also propagate a potential blowout.

While it comes down to personal preference, Trovato has found that it is better to mill the square groove into the cylinder head and machine the receiver groove into the engine block. In many cases, blocks are made from cast iron, which is more likely to hold onto a sharp, square edge long term than an aluminum cylinder head that can round over time. In the instance of aluminum engine blocks, the receiver grooves are machined into the iron cylinder sleeves.

Trovato has ‘been running copper gaskets forever’ and prefers at least an .050-inch-thick gasket. Personal experience gives the nod to Clark gaskets, as they offer a truly “dead soft” material and their pliability tends to squeeze best providing equal sealing on the deck surface.

“This design is great for both nitrous and boost,” says Trovato. While many run MLS gaskets, he feels everyone is entitled to their opinions. “I’m going to run whatever top fuel runs.” We can understand why, as they are at the forefront of horsepower production and cylinder pressure threshold limits. The problem Trovato found when running MLS gaskets is that when they fail, something is torched in the process, leaving one with the almost impossible task of fixing things quickly during a race.

Since this design has only been on the market for short while now, Trovato, through utilizing the trial-by-fire testing method, has started implementing the ring’s use at the recent 2021 NMCA race in St. Louis. Inspections post-race show much promise and potential.

“The ultimate assessment would be instead of using a standard leak down tester, we pull the valvetrain, close all the valves, seal the chamber and fill it with a shop air source to try and force a possible breach to find the upper limits of the cylinder sealing abilities” says Bill.

For drag racers, every small advancement in horsepower is a potential improvement in elapsed time on track, and as a result, the pursuit is both relentless and endless for those who want to stay on top… and they will go far outside the proverbial box to find the smallest amount of ‘gold’ to keep one step ahead of the competition.

Looks to us like Trovato has found some gold for himself here.


BTR Performance
(585) 303-7560

Visner Engine Development, LLC
(616) 726-6600