Hand-Porting Motorcycle Engine Cylinder Heads. A Dying Art Form.

hlFor those who don’t know, “hand-porting” is modifying the intake and exhaust ports of an internal combustion engine to improve the quality and quantity of the air flow, hence your engine performance. It is a task that today’s generation of techs would rather leave to machines. But there are a handful of rebel-minded innovators left in the United States that continue the art of “head porting” by hand. Joe “Biker” Malloy, the face of  H&L Performance Engines is one of them. In the text below he stresses the importance of keeping the tradition alive. 

“Is faster always better?  Today, in the rush of instant gratification, most people CNC-port their engine heads, meaning they take a cast head, which is of course subject to casting imperfections, and then they have a CN machine port it, running off of a computer program that ports the heads, one after another, exactly the same. 

Anyone who knows anything about high performance engines, knows this: no matter how well-built the engine and no matter how well-planned the part configuration, without proper head flow, every effort towards performance will be futile. MACHINE versus. MAN… Customized parts, like heads for instance, takes time!  So, where’s the middle ground in all of this? Well, H&L believes excellence can be achieved through that perfect combination of old-school precision and state-of-the-art knowledge, machinery and tooling.   

Head porting by hand is a unique shop experience for every project. It allows for correction of any imperfections created during the casting process. Best of all, hand porting includes the experienced touch and feel of a machine shop artist, like H&L Performance’s highly elusive (and widely respected) Tom Haner who has been head porting by hand for thirty-five years. 

Customizing your bike is an investment in a piece of art. A show of excellence when ridden and it’s worn like badge of honor to represent the long history of the motorcycle engine evolution. Hence the saying, “Don’t rush the beauty if you want to feel the beast”. H&L Performance’s heads are each flow-tested on a top-of-the-line Superflow Computerized SF-600 Flow Bench, with velocity probes that ensure maximum flow with optimal velocity. With well over 50 years of combined experience, and a machine shop that offers the best equipment money can buy, H&L performance has perfected the art of engine rebuilds, from stock configurations to boring and stroking to reach absolute maximum potential” Joe “Biker” Malloy, H&L Performance Engines.

11 Responses to “Hand-Porting Motorcycle Engine Cylinder Heads. A Dying Art Form.”

  1. 1 American Flyer May 17th, 2009 at 11:22 am

    H&L is a top company by top craftsmen. Their engines are a work of art. By far the “best looking” and performing motor on the market!

    I have one of their 131’s on my bagger and believe me when I tell you that fast is an understatement. I have had zero issues and I’m hitting 26K on the motor.

    Keep up the good work guys! We all appreciate work and quality.

    PS. Tell Joe the rock star he needs a hair cut 🙂

  2. 2 J May 17th, 2009 at 2:00 pm

    Well, uh, yeah, that’s kinda the point with CNC-machined heads- I WANT them to be exactly the same, head to head, cylinder to cylinder, port to port….. At least you’re not completely adverse to the Modern Era, with that nice flow bench!

  3. 3 Mike Greenwald May 18th, 2009 at 12:39 am

    You certainly are missing the point. Take a look at the metallurgy and take a look at the anomalies within each and every part. Once you know that it is perfect, your CNC thoughts might work.

  4. 4 Conrad May 18th, 2009 at 12:54 am




    Joe built us a monster engine not long ago and I must say they are amazing engines. Once you get your eyes off the basics and put some thoughts and theory into the major picture of POWER you will understand what Joe is talking about. Until then you are lost in the World of machines.

  5. 5 Jeff Nicklus May 18th, 2009 at 9:04 am

    As Conrad said ….. Joe is the man!

    Over & Out,


  6. 6 mark May 18th, 2009 at 1:08 pm

    I agree that CNC is not enough. I have been told by my builder that it is a good starting point.

    Look to the guys out there running the salt flats and the dry lake beds. Ask them about head porting and polishing and see if CNC is enough.

    Great article. I am going to be doing a similar piece for Bikernet. Education is key to the build of a good motor. Too many shops just bolt shit together and that is fine if you don’t want a hot rod. My pops used to talk about balanced and blueprinted motors. Newbies out there need to talk to some of the older folks out there…..

    Way to go Joe…keep fightin’ the good fight.

  7. 7 jurneyman May 18th, 2009 at 6:31 pm

    I am not a regular contributor to Cyril’s Blog, but I swing by to see what might be happening in the High Performance world, and comment if can add something of value. This article on CNC vs hand portingcaught my interest. First a little background, I first started learning to port with hand tools, by
    learning on whatever junk heads I could find probably 30 years ago. These day’s I am mostly working to improve the components and efficiency of the Feuling designed 4 valve heads. OK enough of the qualifications, and getting to the point. I personally feel there is a valid reason the CNC has a place in the Engine head modification field,. I find that the average customer at first just wants to upgrade from a EPA restricted motor that the OEM’s are forced by law to conform to. Let’s say that, when that average customer starts to consider even a basic upgrade,pipes, air cleaner ect. it isn’t to much longer, and he starts looking into a carb, cam, ignition, then he finds out that the heads are also restricted to make the gas analyzers happy. Using the H.D.evo as an example, larger valves are needed to optimize the other upgrades, next the flow should be increased to match everthing else to have a balanced upgrade.. Now the customer knows, from reading magazines ecr. that to have optimum results from his investment the complete upgrade should be performed by the same shop, under the guidance of an experienced builder. Now going back a few steps when the customer realizes to have one shop for the total package, and this shop has the capability to port his heads, that most other shops lack, it is here because of the CNC’s ability to port his heads, fulfilling the minimum requirements of his upgrade quickly, shorting his down time ,the customer will then happily purchase all of the parts the shop recommends for his upgrade, thus the shop not only gains the income from the machining labor, but the labor, to install the parts.

  8. 8 jurneyman May 18th, 2009 at 7:46 pm

    I was going to write the following in the original post, but I had to go out to the shop, After reading this comparison of porting thread, I believed that no further elaboration was necessary to convince most of the contributors, since they showed they already understood and appreciated the benefits derived from porting by hand.

  9. 9 TAC May 26th, 2009 at 1:40 pm

    You will have to pry my cold dead fingers off my 131!
    I have many flaw-less miles with more torque and horsepower than I could have ever imagined possible from a naturally aspirated engine. I can’t say enough good things about H&L Performance.
    Tom & Joe are the best of the best and provide awesome one on one customer service. The head work they do is phenomenal along with everything else. If you are in the market for a new engine or head work you should give them a call. They will defiantly give you the most bang for your buck.
    I can also attest to the statement below……


  10. 10 TAC May 26th, 2009 at 1:43 pm

    Tom also needs a hair cut!


  11. 11 Bigwoody Sep 11th, 2011 at 7:43 pm

    Talked to Bob Wood, “MASTER” cam grinder:
    tWIN TEC IGNItion
    BoB wood rocker agliment kit for over 600 lift cams.

    Total expenditure 8500. not cheap but 170 reliable horsepower.

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Cyril Huze