Competition & Street Headwork

The real art in performance engines,.. is in cylinder head design and modification. There are major differences between 2 valve push-rod heads, and multi-valve double overhead cam cylinder heads,..but the laws of physics apply to each. Only complicated and expensive multi-axis CNC programs can imitate the complex shapes the cylinder head porter develops as necessary for optimum flow . This why hand porting is , and will continue to be , in small runs, the only and BEST alternative to that technique. Understanding different design philosophies is key to achieving maximum results. Needless to say, comparing maximum CFM flow at full valve lift is somewhat misleading at best, and less than professional at worst. As with most pro head porters,..you won't find much detail in these pages. This knowledge has been hard won over the years and is one remaining area of secrecy. Without question, good port and valve work gives the BIGGEST BANG for the buck,..BAR NONE ! This type of work is also one place do-it-yourselfers are well advised to avoid. Small mistakes can cost a lot of power.

Stage I

4 & 5 valve street porting & competition valve job. Includes:

  1. Strip & thoroughly clean head,..index all parts
  2. Port per customer's needs
  3. Multi-angle valve job w/ stage I chamber mods
  4. New valve stem seals
  5. Adjust spring height w/ stainless shims
  6. Check/set all specs
  7. Re-assemble w/ cams & set lash/re-shim

average 10 - 15 rear wheel HP Power Increase,.... MUCH more midrange $800.00 plus parts

Stage II

Includes all Stage I work plus:

  1. Port per customer needs
  2. Oversize center intake valves included on 5 valve heads
  3. Stage II chamber & piston mods ** titanium retainer & spring kit recommended
  4. Before and after flowcharts can be included

Up to 25+ rwHP increase $1200.00 plus parts

Stage III

Includes all Stage II work plus:

  1. Port for max peak power
  2. Install custom valves, (free flowcharts april-september only)
  3. Stage III chamber, piston and compression mods
  4. Thermal coat piston crowns
  5. Head & cyl block blueprinting and relief ** makes max power with all motors, big bore/strokers best

Maximum possible power increase: $2000.00 plus -pro-street, pro-mod, pro-gas, etc.

Headwork for twin cylinders (Harley Davidson and others) available.
Starting at $200.00. example HD stage II


The best port/valve work for ANY motor
(For any setup/tune)


Money back guarantee or another head
(If any similarly priced head flows more total average CFM with independent flowbench testing.)


NOTE: All single, twin, and triple cylinder headwork is proportionately priced/ same guarantee....Please let us know if you want PERFORMANCE or pretty,..( or both ! :-)

J.C. Performance Engineering

617-06 Bicycle Path
Port Jefferson Station, NY 11776
516-928-9863

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Page created & maintained by JC, jeff@jcperformance-engines.com. Created: 9/25/96