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Tech Review-Erson High-Performance Valves

Posted By: Steve Baur
Written by Jack McInnis
Photography courtesy of the manufacturer

Your engine relies on its valves to control the flow of air and fuel into the cylinder, seal the combustion in, and allow the spent exhaust gasses to exit. The process seems simple enough, but engine rpm range, combustion temperature, and exhaust gas temperature among other factors will place special demands on the valves, and as Mom used to say, “If you can't take the heat, stay out of the kitchen.”
The choices available include stock valves, stainless steel valves, and titanium valves. Each material features properties that are suited to particular applications.

Stock valves are typically made from lower carbon steels, which work well in standard passenger car applications. Low carbon valves are harder than stainless steel at room temperature, but their strength decreases as combustion temperatures go up. Stock valves can often work in mild performance situations, but if an engine is showing signs of valve burning or premature valve failure an upgrade to performance valves is going to be money well spent.
Stainless steel valves, on the other hand, increase in hardness and strength at elevated temperatures. Erson’s stainless steel valves are the company’s most popular valves for street, dirt track, and drag racing engines because of their enhanced flow characteristics and their ability to maintain durability at high temperatures. They are available in two styles to suit varying levels of engine performance.
Erson Sportsman Race (2000) Series valves are created using a one-piece forging of EV8 high strength stainless steel alloy. These valves are popular for street performance and sportsman racing applications. They are far superior to stock valves and offer much higher heat resistance. 
Erson Competition (1000) Series valves are made from a one-piece forging of PS824 premium stainless alloy that can withstand temperatures up to 1,600 degrees.

Competition Series valves are recommended for roller-cam applications or valve springs with 130 psi of seat pressure and 450 psi of open pressure. These are popular valves for serious dirt-track and drag-racing engines, with alloys that can handle the high temperatures resulting from power adders.
In addition to their superior high-temperature durability, one of the advantages of using a high-grade stainless such as EV8 or PS824 is that the margin on the valve head can be made thinner with less danger of cracking or burning, making for a much lighter valve.
Erson valve stems are hard chrome plated to reduce stem and guide wear. Chrome has the added benefit of microscopic surface pores that retain oil and help to reduce wear. Hard chrome plating is much thicker than flash chrome, making it far superior for valve stems because it is more durable and lasts much longer.
Both 1000 and 2000 series stainless valves feature hard stellite tips, so that lash caps are not necessary. Stainless is not hardenable, so a hardened tip must be welded onto the stem to prevent wear, otherwise, hard lash caps are required.

Both series feature an undercut stem design, which increases airflow and reduces valve weight by as much as 10 percent. The valve head is swirl-polished and features a back cut to further improve its flow characteristics.
For turbocharged, supercharged, and nitrous engines, you may want to upgrade to an even higher-temperature exhaust valve alloy for added protection. These applications may require Inconel exhaust valves. Inconel is a super-alloy with high levels of nickel and chromium and a small amount of titanium, designed for use in high-heat environments. It is also more dimensionally stable than steel under high-heat use, so it doesn’t tend to creep or grow as much at high temperatures. Inconel, however, requires high temperatures to perform correctly. The material is more brittle at lower temperatures and becomes more elastic and stronger with elevated temps, so these are not a good choice for engines that will operate at lower temperatures.
Titanium valves are designed to reduce valve train weight for high-rpm and extended high-rpm applications where valve weight is important and cost is not a consideration, as they are very expensive. However, for extreme-temperature situations such as blown, turbocharged, or nitrous engines, titanium may not be the ideal choice, particularly on the exhaust side. Titanium is also not a good choice for most street engines which won't be torn down and serviced regularly.
Stainless steel valves are the most commonly used valves for the majority of performance and racing engines, offering great performance and durability at an affordable cost. Good quality valves which are correct for your application will be an investment you won’t regret.
Erson Cams
(800) 641-7920

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