Book Excerpt: How to Port and Flow Test Cylinder Heads WHAT IT TAKES TO MAKE POWER
HOW TO BE A SKILLED HEAD PORTER The cylinder heads influence what combination of parts and the setup that's optimal for the rest of the engines spec. For instance, the camshaft required for a ported big-valve cylinder head usually requires, for a given set of duration figures, quite a different cam spec to achieve top performance compared to the stock head. Also, strange as it may seem to a novice in this field, the original cam often does not deliver optimal performance, and I am no talking in terms of valve opening duration here. For a given intake opening duration and lift, there is optimum exhaust duration and a set of valve opening and closing points that can make or break your efforts as a head porter. If you want to get the best results from your porting efforts, you need to understand how the changes you have made impact the rest of the engine's requirements, so the best possible outcome is achieved. Also if you are going to make head porting a career, you will be the first person your customer asks advice for cam selection, intake, exhaust, and the like. You have to give them astute and accurate answers, otherwise, trust me on this, unless your price is rock bottom, it will be the last time they come to you. If you have the best flowing head in the world for the application at hand, you must also have a good notion of how best to use it. All that you need to know to make the best of any head comes under the topic of "combinations."
PORTING TOOLS, CONSUMABLES AND SAFETY
Granted, this chapter is titled "Porting Tools, Consumables and Safety," but I address the safety issues first because it is vitally important you understand just how critical they are.
EYE AND LUNG SAFETY Make no mistake about it - an 18,000-rpm die grinder with a carbide cutting metal is a nasty little predatory critter spitting out fine, razor-sharp shrapnel. It's not just the very sharp shards of metal, but that they also come off the work piece at speeds up to 60 ft/sec. If they hit you, the end on these razor-sharp shards will, with ease, penetrate your eye up to 1/16 inch deep. That means a "right now" trip to the hospital for some painful eye care. So get a good set of safety glasses, the type that wraps around, so that ricocheting shards don't get into your eyes from the side. With your eyes taken care of, it's time to consider your lungs. Do not, for any reason, use abrasives without first putting on a mask. You don't need to do that many times before lung damage (usually silicosis) goes from a possibility to a certainty. I can be very categorical here because I found out the hard way!
Subject: DIY: Automotive Performance: Cylinder head porting and flow testing how-to. ISBN-10: 1934709646 | ISBN-13: 9781934709641 | CarTech Books SA215
- What it Takes to Make Power
- Flow Testing Procedures
- A Flow Bench - Build or Buy
- Wet-Flow Testing
- Porting Aftermarket Heads
- Porting Tools, Consumables and Safety
- Five Golden Porting Rules
- Developing Functional Ports
- Valve Shrouding
- Developing Functional Heads
- The Combustion Process
- Maximizing Compression Ratio
- Source Guide