Cylinder Heads - Twin Cam
Zipper’s CNC Ported Twin Cam Harley Cylinder Heads. Stage The Stage I head includes a Zipper’s Performance Valve Job (Seat and guide work), ” O.S. Valves, new guides and 7mm conical springs. The head gasket surface will be skim decked to assure a true/flat sealing surface. Dec 31, · Short-Block Charlie describes step by step porting a Scotsman's head.
Our Stage II CNC heads employ special high velocity ports developed specifically for riders in search of early torque with broad power.
With ports designed for high-velocity airflow, matching these heads with the proper camshaft and exhaust produces amazing power. Perfect for riders of heavier machines who want great acceleration just by turning the throttle — no rowing of the gearbox and high RPM needed! Click Here to complete your Job Order Sheet.
The add to cart button is disabled because the following component is not selected:. After cleaning, CNC porting and guide replacement, SportMax heads are fitted with high oprt 7mm stainless steel 1. Special valve seat machining and blending for a smooth transition to the ports is performed by our highly skilled specialists. Valve springs are custom-packed to handle valve lifts up to. These heads are designed for optimum results with the factory throttle body and injectors lower cost!
Work is performed on your supplied head cores; shop time is approximately 5 business days allow for additional time during peak season. Exchange heads may be available if the condition of your cores qualifies. You can also purchase heads outright without supplying a core set.
We will supply clean, reconditioned hezds castings for your application — add part to your order. International Customers — Import duties are not required when to shipping your castings for modification.
Special low shipping rates are available for your cores; contact your how to do in text citation of website representative for details. Supply us with your piston volume and camshaft selection for final cc volume through decking.
Improper cleaning methods can actually do more harm than good; we suggest you allow us to properly prepare your heads for modification. Extreme care is taken during our preparation process to preserve component finishes. A small cleaning charge applies to heads sent in for modification.
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The porter uses a flow bench to measure his progress. Before starting work on your cylinder heads, the porter will place your cylinder head in his flow bench and run air through it, measuring its throughput in cubic feet per minute (CFM). As the porting process goes on, the porter measures again and again. Level 'B' CNC cylinder head porting. Fuel Moto offers comprehensive in-house cylinder head services for late model Harley Twin cam engines. With nearly 20 years of porting experience in a wide range of applications we can provide a cylinder head package for nearly any combination using our proven programs that have been developed on the flow bench, the dyno, and in real world testing for. We offer three levels of CNC porting service for Twin Cam Heads: The Impact service treats your heads to our exclusive and proven 4-Axis CNC port treatment, followed by hand finishing, bronze manganese valve guides, a custom radius valve job, sizing of the chambers to achieve your desired compression ratio, and decking your heads to get a perfectly flat gasket surface.
Twin Cam Tech Tip Download. Tech Tip Articles. Fun to Ride Guide. Custom Engine Estimate. Custom Engine Building. Other Products and Services. Perry's Bio. Catalog Request. Think if your Harley engine as a pump. The more air if flows, the more power it makes.
All mass-produced engines have less than optimal volumetric efficiency, because the manufacturers cannot afford the skilled labor required to clean up the ports of each individual engine. Because of its complexity and the physical dexterity required by the operator, porting is the black art of engine tuning. It can not be done by a machine, only by a person.
Apart from the cost of the service, there is no downside. He works to optimize the radius around the valve seat, the width of the valve seating area, transition into the combustion chamber, and radius on the back side of the valve. The goal is smooth flow, not sheer volume. A common misconception is that bigger ports are better—on street engines the opposite is more often true!
Harley engines are very sensitive about their exhaust-to-intake ratio. They run best when that ratio is around 90 percent, but factory levels are more like 78 percent. A good porting job can give you the optimal exhaust-to-intake ratio for your Hog, but a bad one can make it worse. Expert porters know that efficient atomization —the transition of fuel from liquid to vapor—gives the best Dyno numbers, and the secret efficient atomization is the finish of the ported surfaces: rough in some areas and mirror-smooth in others.
If your heads come back this way from a tuner, expect less, not more power! This process has consistently given the best Dyno figures for Harley engines of all types. But bear in mind that the process is slightly different, depending on the generation of Harley engine the porter is working on.
The porter uses a flow bench to measure his progress. Before starting work on your cylinder heads, the porter will place your cylinder head in his flow bench and run air through it, measuring its throughput in cubic feet per minute CFM. As the porting process goes on, the porter measures again and again. Flow numbers are achieved through common flow bench calibration standards. Like all statistics, be suspicious about overly-dramatic flow bench numbers, and take their source into account.
Porting should be the starting place in your Harley engine upgrade program. Do it before you add pipes, a new carb, or anything else. A sure way to look like a beginner is to hang a bunch of power mods off your non-ported Hog!
Imagine you are commissioning a sculpture, and have in your possession a valuable block of Carrara marble, the same type Michelangelo used to create his statue of David. Like selecting a sculptor, you choose a porter by examining his work, reviewing his career, and talking with his previous clients. There is no substitute for experience. Ask, and verify, how long the porter as been working on Harley engines, and which types.
Your porter should be a specialist, not a general-purpose mechanic. Like other master craftsmen, porters tend to be individualists—they often set up their own shops rather than work for dealerships or general-repair operations.
Take your time to seek out a good porter. Be prepared to wait a couple of weeks, and you will be rewarded with an engine that, for its lifetime, will run noticeably smoother and make better power across its rev range. Related Articles. Super Port Flow.
Porting the Evo Big Twin. Tooled Finish. Test Data. Twin Cam 88 Data Sheet. Twin Cam 88 Flow Chart. Evo Big Twin Data Sheet. Evo Big Twin Flow Chart. Sportster Data Sheet.
Sportster Flow Chart. Shovelhead Data Sheet. Shovelhead Flow Chart. Panhead Data Sheet. Panhead Flow Chart. Ironhead Sportster Data Sheet. Ironhead Sportster Flow Chart. Contact Perry Kime at or via e-mail. All rights reserved. All prices subject to change without notice. Trademarks and model names are the property of the trademark holders.
Any add-ons you install to increase performance different pipes, carb, etc. Why all stock engines should be ported Think if your Harley engine as a pump.
How porting is done So what exactly does an engine porter do? Better atomization via the Tooled Finish technique Expert porters know that efficient atomization —the transition of fuel from liquid to vapor—gives the best Dyno numbers, and the secret efficient atomization is the finish of the ported surfaces: rough in some areas and mirror-smooth in others. Flow bench results—and fibs The porter uses a flow bench to measure his progress.
Porting first, add-ons later Porting should be the starting place in your Harley engine upgrade program.