Auto PSRU makes Propeller Speed Reduction Units (PSRUs) for experimental and homebuilt aircraft. Our gearboxes allow selected automotive engines to drive aircraft propellers at the required speed.
Designed for selected automotive engines producing 150 to 300 horsepower.
Reduces engine speed for selected automotive engine conversions in homebuilt aircraft.
Built for experimental aircraft using compatible automotive engine conversion systems.
Designed for high-power aircraft applications, including suitable aerobatic airframes.
Auto PSRU makes Propeller Speed Reduction Units (PSRUs) for experimental and homebuilt aircraft. Our gearboxes help builders use selected automotive engines to power aircraft propellers.
Our firewall-forward engine packages offer an alternative to certified aircraft engines. We work with Subaru four- and six-cylinder engines, Mazda 13B rotary engines, and Chevrolet LS engines. Our aircraft PSRU gearboxes can be adapted for different engine setups ranging from 150 to 550 horsepower, depending on the model and application.
The 300Z PSRU is designed for inline four- and six-cylinder engines, V6 engines, and smaller V8 engines.
Based at Hillsboro Airport (KINJ) in Texas, Auto PSRU focuses on building dependable gearboxes for experimental aircraft projects.
Our mission is to provide the PSRU’s (a gearbox that is a Propeller Speed Reduction Unit), engines, parts, and services for builders to use automotive engines as a credible, reliable, viable, and affordable alternative to certified aircraft engines.
We make several standard PSRU’s rated from 180 to 550 horsepower to fit a wide range of aircraft projects as detailed on this website. All of our PSRU’s have independent filtered lubrication, roller bearings, and support hydraulic constant speed propellers. The unique features of each of our PSRU’s are explained in detail on the website.
We provide our PSRU’s and services with options to meet the many levels of builder skills. Most builders want one of these two options:
Auto PSRU offers firewall-forward (FWF) kits for selected automotive engines used in experimental and homebuilt aircraft. Each package includes parts to help with the engine conversion.
These packages use Chevrolet LS V8 engines with aluminum construction, liquid cooling, and electronic fuel injection. Starting in 2024, new crate engines are no longer included.
Our Subaru engine conversion kits include the 250Z PSRU with a fully automatic centrifugal clutch. Included are the parts needed to convert compatible 2.5L and 3.0L Subaru engines for aircraft use.
Our Mazda 13B engine conversion kits include the 250Z PSRU with a fully automatic centrifugal clutch and the parts needed for the conversion. Engine availability and condition should be confirmed before ordering.
“We wanted an engine setup that suited our RV-10 and the way we fly. We’re happy to have an aircraft we can enjoy taking on trips and flying whenever we get the chance.”
Do you have questions about our PSRU gearboxes, firewall-forward packages, or engine conversion kits? Get in touch with us. Tell us about your aircraft project, and we’ll help you find the information you need.
You can also email us at
Stuart@autopsrus.com
Read our aircraft engine conversion articles and technical resources to learn more about automotive engines, cooling systems, and engine options for experimental aircraft.
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Learn about the differences between electric and mechanical water pumps and how they work in engine cooling systems.
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Learn about the Chevrolet LS3 engine and its features for automotive engine conversion projects.
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Understand why water is used in engine cooling systems and what to consider when choosing a coolant.
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Read about alternative engines for experimental aircraft and the points to consider when selecting an engine for your project.
Find useful maintenance manuals, technical bulletins, and engine identification information for your Auto PSRU products and engine conversion projects.
Read the available maintenance documents for information about specific gearbox components and maintenance procedures.
Need to identify your Subaru engine? Our guide shows where to find the engine codes on the engine block. Use this information to help identify your engine before choosing a conversion kit.
1000 Airport Blvd
Hangar 104
Hillsboro, TEXAS 76645
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