By: Ontario Race Fabrication  09-12-2011
Keywords: Tax, engine

ORF builds and installs custom roll bars and roll cages to CASC specifications.

Car weighing & Corner weighting

ORF has a fully digital corner weighing scale system that allows us to corner weigh your coilover suspension, this system gives exact weights at each wheel, the cost is $50 per hour.

Basic and Installed Cost

4-point roll bar


6-point roll cage


This rollbar is designed to be built into a cage with a ladder door bars.

An engine needs air to burn the gasoline: the more air that is available to the engine, the more gasoline that it can burn. When you allow the engine to have more air per cycle the result is more power.

If you look at other performance items, such as exhaust, headers, air intakes, and larger throttle bodies, they are all doing what head porting does—allow more air into the engine—but to a lesser degree.

In most cases, head porting realizes more power than other "bolt ons," however, that is not to say that the other modifications are not important. In conjunction, the modifications allow even more air flow and greater performance.

The biggest bang for your buck in engine power is adding a camshaft coupled with a good head porting.

Head porting is important because is OEM manufacturers often looking for the cheapest solution to increase their profits. When they do head casting, the port surface and casting lines left in the ports are not highly desirable.

In most cases, OEM head design focuses on fuel economy and low to mid RPM operation. This is fine for day to day use, but in racing we concern ourselves with higher RPM range, which is where the engine operates and generates power.

These imperfections restrict the incoming air charge, and the exhaust, reducing the overall engine volumetric efficiency (VE).

In a naturally aspirated engine, our goal is to get as close to 100% volumetric efficiency as possible, meaning that we want the combustion chamber 100% full with an air charge so that we can apply 100% of the fuel burnable with the air charge. Forced induction requires a slightly different philosophy.

Ontario Race Fabrications head porting pricing is very affordable. We offer a number of head porting, and connected, options.

Note: the average flow improvements vary, depending on the OEM head.

You must deliver the head stripped down (no valve train or cams installed) and bring the intake and exhaust values, along with a new intake and exhaust gasket (ORF returns these unharmed)

Delivery is 1.5-2 weeks, for a 4 cylinder head.

Street Port—$300 + tax

  • Prepare intake and exhaust mating surfaces
  • Port matching intake and exhaust
  • Clean up intake and exhaust casting lines
  • Polish exhaust and intake ports

Average flow improvement: 2-4%

Full Port—$400 + tax

The Street Port, plus:

  • Blending valve bowls into the intake and exhaust ports
  • Minor work to the short side and roof of intake and exhaust ports

Average flow improvement: 4-6%

Race Port—$500 + tax

The Full Port, plus:

  • Reshaping port dividers, if any
  • Reshaping intake and exhaust short side and roof
  • Clean up combustion chamber hot points and casting lines

Average flow improvement: 6-15%

Intake Manifold Porting—$80 + tax

  • Matching head to intake manifold
  • Porting runners ~6" into runner

Throttle Body Porting—$50 + tax

  • Cleaning casting lines
  • Porting throttle body

Spark Plug Indexing—$80 + tax

Indexing spark plugs faces the open side of the spark plugs' electrodes towards the incoming fuel injector spray.

Indexing the spark plugs is good for a few HP.

Head Flowing Services—$150 + tax

Consists of printed head flow data in CFM at 28" and 500 thousands lift.

The information in this article was current at 06 Dec 2011

Keywords: engine, Tax

Contact Ontario Race Fabrication


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