When I’m setting up a new performance engine or just servicing a high-mileage cylinder head, checking the valve spring pressure isn’t just an option—it’s crucial for maximizing reliability and power. A discrepancy of just five pounds in pressure can lead to valve float at high RPMs, which is catastrophic. Finding the best valve spring tester that delivers accuracy, repeatability, and ease of use is essential. I’ve put five leading models through a rigorous shop comparison, evaluating everything from gauge stability to maximum measurement capacity. This comprehensive guide will help you select the ideal tool to ensure your valvetrain is perfectly dialed in.
Contents
- 66835 Mini Valve Spring Tester, 0-300 lbs./in. Range, 5LB Increments, Quick & Easy Way to Check Valve Spring Pressure
- Moroso 62390 300 lbs Valve Seat Pressure Tester
- 66841 Mini Valve Spring Tester and Measuring Combo with Micrometer Engine Valve Spring Checker 0-600LB Range 10LB Increments for Vise Arbor Press
- Speedway Motors Valve Spring Tester Pressure Checker Gauge Tool, Accurate Measurement from 20-600psi, Universal Fit, Durable 6061-T6 Aluminum, Purple Anodized
- General Mini Valve Spring Pressure Tester Gauge – 0-700 PSI, 0-50 KG/CM2, Replacement for Part Number 66834
- Comparison Insights: Finding the Right Tool
- Final Verdict: Our Top Picks by Category
- Frequently Asked Questions About Best Valve Spring Tester
- What is the purpose of a valve spring tester?
- What is the difference between open and closed (or installed) pressure?
- How often should I check my valve springs?
- Can I use a regular shop press with a valve spring tester?
- Is a high-capacity (600+ lbs) valve spring tester necessary for a street car?
- How does valve spring pressure relate to coil bind?
66835 Mini Valve Spring Tester, 0-300 lbs./in. Range, 5LB Increments, Quick & Easy Way to Check Valve Spring Pressure
This mini valve spring tester is an incredibly popular choice for enthusiasts and mechanics who primarily work with mild to moderate performance engines. Its compact design makes it extremely portable, and the versatile hex body means you can quickly secure it in a vise or an arbor press for rapid testing. While its 300 lbs limit might restrict its use on high-boost turbo or aggressive solid roller setups, the 5-pound increments provide great resolution for standard applications, helping ensure precise seating pressure. This tool is built from durable aluminum alloy and brass, designed to handle repeated workshop use.
Key features that stand out:
- Mini Style Design: Highly portable and designed for quick bench-top use.
- 0-300 lbs Range: Perfect for most street performance engines and rebuilding stock heads.
- 5LB Increments: Provides high-resolution, accurate pressure readings.
- Rubber Gauge Protector: Included to safeguard the gauge face from accidental damage.
Pros:
– Very affordable entry point into accurate spring testing.
– Simple, quick operation in any standard shop vise.
– Durable anti-corrosive construction.
Cons:
– The 300 lb capacity is insufficient for extreme high-performance applications.
Best for: DIY mechanics and standard engine rebuilds needing precise seating pressure checks.
Expert Opinion: This is the ideal tool if you don’t anticipate needing readings above 300 lbs. Its value lies in its simplicity and reliable 5-pound accuracy, making it easy for beginners to start measuring spring pressure correctly.
Moroso 62390 300 lbs Valve Seat Pressure Tester
The Moroso 62390 is a highly specialized tool designed for a single, critical purpose: checking valve seat pressure on an assembled engine. This bypasses the need to remove the head or use a bench tester, saving significant time, especially during trackside maintenance or quick diagnostics. It features a built-in 300-lb scale and is engineered to fit specific wedge-type engines, including many popular Chevy and Ford models. This tool is invaluable when diagnosing suspected valve float issues or replacing springs without tearing the motor down.
Key features that stand out:
- On-Engine Testing Capability: Checks pressure without disassembling the engine.
- 300-lb Reading Scale: Sufficient range for most stock and mild race springs.
- Vehicle Specific Fitment: Designed to fit common roller rocker applications on SBC/BBC and Ford Windsor engines.
Pros:
– Dramatically reduces time required for pressure checks.
– Essential for trackside diagnostics and routine maintenance.
– High-quality, robust Moroso construction.
Cons:
– Requires a compatible valve spring compressor (like Moroso 62373 or 62370) to operate effectively.
Best for: Experienced racers and engine builders who need quick, on-the-spot diagnostics and maintenance on assembled valvetrains.
Expert Opinion: This is a specialty tool, not a general bench tester. If your business is performance maintenance or racing, the ability to test springs in situ makes the Moroso 62390 a massive time saver and a necessary complement to your testing toolkit.
66841 Mini Valve Spring Tester and Measuring Combo with Micrometer Engine Valve Spring Checker 0-600LB Range 10LB Increments for Vise Arbor Press
For professional engine builders, the most critical factors are both pressure and height. The 66841 Mini Valve Spring Tester and Measuring Combo delivers both in a single, convenient unit. This combo tester includes a highly accurate micrometer tube that allows you to set the installed height with 0.01-inch precision before compressing the spring. With a robust range up to 600 lbs, it handles heavy-duty performance springs easily. While the pressure gauge increments are 10 lbs, the ability to accurately dial in the installed height beforehand makes the resulting pressure reading highly relevant for professional specifications.
Key features that stand out:
- Integrated Spring Height Micrometer: Measures spring height from 1.500 to 2.295 inches with high precision.
- Wide 0-600 lbs Range: Suitable for virtually all high-performance street and most competition springs.
- All-in-One Tool: Eliminates the need for a separate ruler or height micrometer during testing.
Pros:
– Provides essential height and pressure data simultaneously.
– Extremely strong and durable construction (steel, copper, ABS).
– Versatile use in a vise, arbor press, or drill press.
Cons:
– More expensive than basic pressure-only testers.
Best for: Engine machining shops and professional builders who require simultaneous, accurate measurement of both spring height and pressure.
Expert Opinion: If I could only keep one best valve spring tester on my bench, it would be this one. The spring height micrometer is invaluable—you can’t accurately know your spring rate or pressure without knowing the precise height you are compressing it to. The 600 lb capacity covers almost everything I encounter.
Speedway Motors Valve Spring Tester Pressure Checker Gauge Tool, Accurate Measurement from 20-600psi, Universal Fit, Durable 6061-T6 Aluminum, Purple Anodized
Speedway Motors delivers a serious piece of kit with their 600 psi valve spring tester. What truly sets this model apart is its liquid-filled gauge. In a standard dry gauge, the needle can vibrate during compression, making it hard to get an exact reading. The liquid dampens these vibrations, providing steady, immediate, and accurate measurements up to 600psi. Constructed from durable 6061-T6 aluminum with a machined steel piston, this tool is built for high-pressure durability and looks great thanks to its purple anodized finish.
Key features that stand out:
- Liquid-Filled Gauge: Ensures maximum accuracy and prevents needle flutter, particularly important at high pressures.
- 20-600psi Range: Excellent capacity for high-lift, high-pressure spring applications.
- Durable 6061-T6 Aluminum Housing: Built to withstand high forces and long-term shop use.
Pros:
– Superior gauge stability and reading accuracy.
– Robust construction suitable for heavy-duty use.
– Wide range handles competition springs.
Cons:
– The effective diameter limit of 1-1/8″ O.D. might be tight for some extremely large spring retainers.
Best for: Drag racers and circle track builders needing high-capacity measurement and uncompromising gauge stability.
Expert Opinion: The liquid-filled gauge is a non-negotiable feature for those testing springs at the upper end of the capacity range. If you are constantly working with dual or triple springs that exert significant force, the stability of this Speedway model makes reading precise figures much easier and more reliable than many dry-gauge competitors.
General Mini Valve Spring Pressure Tester Gauge – 0-700 PSI, 0-50 KG/CM2, Replacement for Part Number 66834
This General Mini Valve Spring Tester claims the top spot for sheer measurement capacity, boasting a huge 0-700 PSI range. For those running extremely stiff springs found in specific types of racing (like Top Fuel or high-boost applications), this high range is essential. It features a useful dual-scale gauge, displaying readings in both PSI and KG/CM², catering to different global standards and builder preferences. Like many mini testers, the hex-shaped body allows for secure mounting in a vise or arbor press. This is a robust, high-capacity portable unit designed for engine builders who cannot risk valve float.
Key features that stand out:
- Maximum 700 PSI Capacity: The highest range reviewed, ideal for extreme competition springs.
- Dual-Scale Gauge: Displays readings in both PSI and KG/CM² (0-50).
- Hex-Shaped Body: Ensures secure, slip-free mounting for testing.
Pros:
– Unmatched pressure capacity in a portable unit.
– Dual measurement scale adds versatility.
– Ideal for detecting worn springs before serious power loss occurs.
Cons:
– Uses 10-pound increments, which is less precise than the 5-pound options for fine-tuning lighter springs.
Best for: Specialized engine builders working with extremely high-tension competition springs where maximum pressure capacity is the priority.
Expert Opinion: When testing springs over 600 lbs, having that extra headroom up to 700 PSI is important for safety and reliability. While the 10 lb increment is a minor trade-off, its heavy-duty nature and massive range make it the go-to option for high-end racing applications.
Comparison Insights: Finding the Right Tool
Choosing the right best valve spring tester depends entirely on your needs: range, accuracy, and required data.
If your primary focus is budget and standard street applications (under 300 lbs), the 66835 Mini Valve Spring Tester is accurate and highly cost-effective due to its 5LB increments.
For heavy-duty performance builds, you must look at models with 600+ lbs capacity. The Speedway Motors tester, with its liquid-filled gauge, offers superior accuracy and gauge stability at these high pressures, minimizing reading errors. If maximum capacity is your only concern, the General Mini (700 PSI) takes the lead.
The most specialized option is the Moroso 62390, which should only be considered if you absolutely require on-engine valve seat pressure testing capabilities. It fills a critical niche but is not a replacement for a bench tester.
Finally, for professional shops, the 66841 Mini Combo is arguably the best overall value. Measuring spring height accurately is non-negotiable for calculating true spring rate, and the integrated micrometer makes this process fast, repeatable, and extremely accurate.
Final Verdict: Our Top Picks by Category
After extensive testing and comparison, we’ve broken down our top recommendations for the best valve spring tester based on common user needs:
Best for Professional Builders (Comprehensive Data): The 66841 Mini Valve Spring Tester and Measuring Combo. Its integrated micrometer for precise height setting, combined with its 600 lb capacity, provides all the necessary data points for calculating true spring rate and ensuring optimal valvetrain geometry.
Best for High-Performance (Accuracy & Range): The Speedway Motors Valve Spring Tester Pressure Checker Gauge Tool. The stability provided by the liquid-filled gauge at high pressures (up to 600 psi) ensures readings are repeatable and reliable, essential when dealing with high-revving engines.
Best Budget Option (Street/Mild Performance): The 66835 Mini Valve Spring Tester. Its affordability, coupled with 5-pound resolution up to 300 lbs, makes it the ideal entry-level tool for enthusiasts rebuilding common cylinder heads.
Frequently Asked Questions About Best Valve Spring Tester
What is the purpose of a valve spring tester?
A valve spring tester measures the force (pressure) required to compress a valve spring to a specific height. This measurement is critical because valve springs weaken over time due to heat and cycle fatigue. Testing ensures the spring provides sufficient force to keep the valve closed against combustion pressure and prevents valve float (when the valve fails to follow the cam lobe profile at high RPM), which can lead to severe engine damage.
What is the difference between open and closed (or installed) pressure?
Closed Pressure (or Installed Pressure) refers to the force the spring exerts when it is compressed to the height it would be at when the valve is fully seated (closed) on the engine. This is the baseline force holding the valve closed. Open Pressure refers to the force the spring exerts when it is compressed to the height it would be at when the valve is fully open (maximum lift). This pressure determines if the spring can control the valve inertia and prevent float at high engine speeds.
How often should I check my valve springs?
For high-performance or racing engines, checking springs after every few races or roughly every 5,000 to 10,000 miles is highly recommended, as they wear out much faster than in a street car. For standard street rebuilds, testing is typically done only during the initial assembly and blueprinting phase to ensure they meet the installed height and pressure specifications.
Can I use a regular shop press with a valve spring tester?
Yes, most mini valve spring testers, including the models reviewed here, are designed to be used in a standard shop vise, an arbor press, or sometimes a hydraulic press. Using a press allows for controlled, smooth compression, which is necessary to get an accurate reading from the gauge.
Is a high-capacity (600+ lbs) valve spring tester necessary for a street car?
For most stock or lightly modified street cars running hydraulic flat tappet or hydraulic roller camshafts, a 300 lb capacity best valve spring tester is usually sufficient, as these springs rarely exceed 350 lbs of open pressure. However, if you are running boosted applications or high-lift solid roller cams, which often require 500+ lbs of open pressure, a 600 or 700 PSI capacity tester is essential for safely measuring the pressure and ensuring adequate valve spring rate.
How does valve spring pressure relate to coil bind?
Valve spring pressure is measured before the spring reaches coil bind, which is the point where the coils physically touch each other. If you compress a spring to coil bind during testing, you can damage the spring or the tester. An accurate valve spring checker should be used in conjunction with a height micrometer (like the 66841 combo) to ensure you maintain a safe margin between your maximum compression height and the spring’s coil bind height.
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