The Truth about Racing Head Gaskets
Silver Bullet, NOT!
For the last several years the racing industry has been enamored with MLS head gaskets, the proponents of which recommend them as preferred for every racing purpose. However, while these head gaskets do have their place in modern street driven engines and some naturally aspirated racing engines, the truth is they are not suitable for high boost or heavy doses of nitrous oxide. To be sure, there may be limited exceptions but the tech lines at SCE are bristling with calls about MLS failures in engines developing extreme combustion pressures.
Plateau
Many of the customers placing the tech calls are former users of copper head gaskets who, no longer wanting to hassle with o-rings and receiver grooves, switched to the MLS gaskets only to have coolant flush out and get under a tire on the first run. In other cases a younger engine builder or enthusiast will search the internet to find sites or commentary which suggest that o-rings are old fashioned and “no one does that any more”. Here, again, the old axiom applies; there’s no free lunch, one cannot reasonably expect to continue the industry trend of ever increasing power levels while doing less to achieve them. It’s just contrary to nature. 5 or 6 horsepower per cubic inch of displacement with a head gasket that was designed for original equipment power levels is asking for trouble, and in this writers’ opinion, may be responsible for a pause in the increase of horsepower industry wide as builders have had to contend with a new limiting factor, MLS head gasket leaks.
Back on Track
Competition is always good for consumers and the migration of MLS head gaskets into the racing arena spurred the creation of the ICS Titan head gaskets by SCE. These head gaskets require no modification of the block or head surfaces because the ICS Titan has a built in o-ring which replaces the old ritual of grooving the block & head for o-rings. Therefore the ICS is a “bolt on” racing head gasket requiring no machining or modification to the head or block, which is what the consumer was asking for. The patented Integral Combustion Seal provides for combustion sealing and effective trapping of combustion gases within the chamber. The introduction of these head gaskets has allowed engine builders to resume the upward power trends of the past, recording in excess of 6.5 horsepower per cubic inch with bolt-on head gaskets.
Upward and Outward
The nature of the engine building beast is to increase power; increased power derives from increased pressure in the combustion chamber which, of course, acts upon the head gasket. The ICS titan has been proven to seal as much as 7 horsepower per cubic inch in a small block Chevrolet and the trend is upward. However, the effectiveness of the ICS combustion seal unavoidably precipitates failure of the head gasket when pressure levels exceed the web strength of the gasket body and it begins to “push” out. Even though the ICS Titan outperforms all other ready to use head gaskets, the fact that the gasket body is not “anchored” to the engine block by way of an o-ring ultimately becomes the Achilles Heel of the gasket. In short the combustion seal is so effective it pushes the gasket body out of the engine in conditions of prolonged cylinder head lift from extreme combustion pressure.
Back to the Future
For the engine builder seeking to push the combustion pressure envelope and thereby set record new horsepower levels there is one inescapable conclusion; we have come full circle, back to the “old fashioned” discipline of placing o-rings and receiver grooves in the block & heads. Copper gaskets with o-rings and receiver grooves provide the engine builder with metal to metal combustion seals having no sealants to scuff off or blow out, a malleable copper gasket body which is pressure formed to the o-ring and receiver groove making a gas tight seal that will withstand cylinder lifting for extended periods. Finally, the gasket body is anchored to the block by the o-ring and groove to guard against pushing out.
Admittedly, the procedure can be tedious and should be done by an experienced machinist; in addition, it requires re-cutting the o-ring grooves when re-surfacing the block or head to maintain proper o-ring to groove dimensions. So much for negatives; this system affords the most aggressive combustion sealing possible which is why it is the means used to seal Top Fuel engines developing 7000 to 8000 horsepower, that’s 14 to 16 hp per cubic inch! Fully double what can be achieved with any bolt-on head gasket.
Multiple Choice
Not every engine project shoots for the moon so there are 4 head gasket options available for any power level you may be targeting. For performance engines up to 10 lbs of boost or 100 hp nitrous systems, choose Proseal Composite head gaskets in compressed thicknesses of .040” or .060”. The ICS Titan offers combustion sealing as well as coolant seals for ease of use in nitrous and forced induction applications on the street or strip. Titan copper gaskets are designed for use with o-rings (and receiver grooves) in the block or head and include built-in coolant seals for leak free performance in water cooled racing engines. Pro Copper head gaskets are used in Alcohol and Nitromethane engines with o-rings (and receiver grooves) usually having no coolant, when used in engines with coolant these gaskets require an additional sealant.
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