Home » Nucleus Sport Elite Products

Nucleus Sport Elite Products

About 75% of the power in your engine comes from the cylinder head. In money terms, you get more B.H.P. from developing your head than any other other part of your machine. In other words, if you are looking for more performance cheaply, your head is the place to spend it on. You’ll get the best return.

Astonishingly, most head parts – even into the 1990s and 2000s – are still in a relatively low state of development. This is caused by the demands and liabilities of mass marketing, mass production line finishing and the need to please the company accountants before company engineers.

Surprisingly, proper parts cost little more than second best.

Our Nucleus Sports Elite stainless steel valves and copper-silicon-nickel Nucleus Power guides are the best available stainless steel valves on the market. These are designed with the benefit of 25 years experience of working on virtually all models, of all makes of motorcycle and with all other aftermarket manufacturer’s replacement and performance parts. Nucleus parts benefit from individual features drawn from many sources, including racing, aviation and long distance trucking, and are manufactured and hand finished to the highest currently possible standards.

Close inspection of Nucleus Sports Elite valves reveals interesting and unique refinements over standard designs. Narrow waisted inlet valves to allow more flow, anti-reversion lips on exhausts. Flame paths on fire faces for combustion chambers with poor ignition features, subtle angle changes to allow combusting gases to roll over. Multi-angle surfaces to widen the spray of mix into the the chamber and direct gases away. Lightening where possible but not to the deficit of compression levels. These and others are what separate Nucleus products from the rest.

They are made from a high chromium 21-4N stainless steel manganese austinetic alloy, to BS 970 349S52. A superior steel from that used by the majority of manufacturers even of stainless valves. They are matt black Tuffride finished to 72 RC Rockwell hardness where standard valves are at about 35 RC and forged in one-piece not friction welded in two. Where as 99% of producers use only stainless steel for the exhaust and another cheaper metal for the inlet, we use the same quality for both.

Two piece valves increase the risk of dropping a valve head at high rpm. Again, one metal is chosen for the stem and another for the head usually for commercial reasons of economy. The two welded are together before machining. The steel we use is chosen for its wear resistance and heat dispersing capabilities and is superior for both purposes.

This section is under development and as it grows we will focus on individual design improvements and how they improve your engine’s performance. The Cylinder Head Shop undertakes development work design and manufacture of small batches of valves for individuals and owner clubs. For inquiries regarding R&D and development or for any general questions, please contact Len Paterson as below.


Nucleus Sports Elite Model Fitment and Prices
Nucleus Street Elite Model Fitment and Prices – Modern
Nucleus Classic Elite Model Fitment and Prices – Vintage
Harley-Davidson Nucleus FDS Valves and Guides
Nucleus Power Guides