Testing Used Engines

The question asked most often by people searching for a used Japanese engine is “how many miles on the engine?” This is a legitimate question, but really not the most important one.

Far more important is the quality assurance measures a company takes before selling you an engine. What kind of inspection does the company perform? And most important—“How does the company test the engine?”

For a quick analysis of a used engines state and quality you can measure cylinder and oil pressure.

Cylinder Pressure—a pressure gauge is connected to the engine cylinder at the spark plug opening. Pressure is measured at each cylinder in terms of pounds per square inch (e.g. 180 psi). The variance between cylinder readings should not be greater than 10%. If it is, a leak-down test would be performed to locate a potential pressure leak in the rings, valves, block or head gasket. Both of these tests are done when the engine is not running.

Oil Pressure—proper oil pressure in a used engine is a great indicator that the internal components are in good shape. Certainly an engine cannot ship with poor oil pressure and in fact much more detailed inspection would be required if low pressure was detected in a used engine.

The best test that a supplier can perform is a hot-run test. This is a live test where the engine is bench mounted and started up. This requires custom equipment and skilled automotive technicians to perform it properly. That is why very few companies can provide this level of quality assurance.

The quality control program employed by Rising Sun Engines, Inc. includes the following tasks:

1. External components are carefully removed from the engine long block. These components cannot be used in the USA. The vehicle owner will swap over their external components to the used engine supplied to them.

2. All external openings are plugged. The entire engine is loaded into a jet-wash machine (basically a big dishwasher) and the outside of the engine is thoroughly cleaned.

3. The cleaned engine is mounted to the company’s exclusive hot-run test bench. It is first run without the exhaust manifolds so the technician can check for smoke from the engine. Once the exhaust system is installed the engine is run again and oil pressure is measured while the engine is running. With the exhaust system in place the technician can listen for abnormal noises from the engine.

4. While the engine cools the technician inspects the engine for obvious leaks, broken parts and checks the valve guides after the manifolds have been removed to make sure no oil is passing. Compression is measured and recorded.

5. A final inspection is preformed prior to shipment to ensure that it is clean, all items are included and all the paperwork (including customer provided test results) is attached.

A great deal of time and effort should be invested in each used engine being shipped. Assuring the quality and condition of the engine is the best way to answer the question about mileage.

Types Of Engine Assemblies

What type of engine assembly you should be asking for depends on what kind of project you are taking on. Typical projects are; engine swaps, partial replacements and direct engine replacements.

If you are looking to spice up your vehicle with a higher performance engine you are doing an engine swap. You will want to find a supplier that offers complete engines. These engines have all the external components supplied and attached so the engine is ready to go. Expect to pay a lot for this and if it is a swap make sure you have done a lot of research before you start.

You may have a very good cylinder head, but a bad lower block. In this case you may want to keep the head and purchase a new, used or rebuilt short block. Typically this engine sub-assembly includes the lower block, crankshaft, connecting rods, pistons, rings, main bearings, and rod bearings. Be sure a qualified mechanic will complete the assembly for you.

Companies that specialize in direct engine replacements usually supply "long block" engine sub-assemblies. A long block includes the complete short block sub-assembly and the cylinder head. The mechanic will use the manifolds, fuel system, ignition system and other external components from your old engine. All of the external components on a motor from Japan are different from those in the U.S., so they are removed to make your installation easier.

The excellent supply of quality engines from used Japanese automobiles has expanded the options for owners of imports that need an engine replacement. Almost all of the used engines being offered are long block assemblies. Sorry engine swappers, but you have to find specialists. Often it is best to buy the complete used Japanese long block assembly versus just a head or short block. This allows the supplier to test the complete assembly for you before you install it.

Quality used long block engine assemblies offer the best value and price combination. The price is lower than a complete engine assembly and the engine can be started up and run before installing it in your car, giving you peace of mind.

Make sure your supplier does in fact start and run your engine before shipping it. You should be assured that a mechanic has measured compression and oil pressure, inspected the assembly, listened for knocks, abnormal noises and checked for smoke.

We hope this helps you choose the right engine assembly for your project and explains what you receive from a supplier of used Japanese engines.

Testing processes and procedures will be discussed in a future article.

The 40,000 Mile Story

Everyday we are asked, "is it true cars in Japan are junked after 40,000 miles?". This is a urban myth. The Japanese government does NOT come and take cars off the road at 40,000 or any other pre-defined mileage.

However, there are real reasons why there are very good, reliable autombile engines and transmissions available from Japan.

First, they put about half the miles on their cars per year as we do in the USA. So, a 10 year old car in Japan might have 50,000 miles on the engine compared to 100,000 on a USA motor.

Second, the Japanese Car Inspection program or sha-ken as they call it in Japan, is a tough bi-annual inspection that every car is subject to. Over 50 systems and components are inspected. The primary reason for failure is body rust. The weather in Japan is like our east coast winter weather--cold and wet. Cars can rust out in 7-10 years.

This combination of light driving loads, rough weather and tough inspection programs has provided us with great access to very good motors and transmissions from Japanese automobiles.

We will NEVER quote you mileage on a motor we offer to you. In fact, unless someone has the entire vehicle with the odometer they cannot really provide you with the exact mileage.

Our focus is on ensuring you that the condition of our engines is excellent no matter what the mileage is. Cleaning, inspection and one-of-a-kind testing is our way of ensuring such quality.

Our next blog post will discuss in detail proper refurbishment and testing protocals. We hope you will visit our web site, www.risingsunengines.com or give us a call (800 660-4664) with your questions.