Home > What is a JDM Engine?




Japanese Domestic Market -Why do we have so many engines?

Lets look at why we have JDM Engines to swap into our cars here domestically. In Japan all cars must pass an inspection called “Sha-ken” which determines if a car is still suitable to be driven on Japanese roads. This inspection can become very expensive and often drive the vehicles value to zero. The older a car gets, meeting the standards set by "Sha-ken" can be more than a hundred thousand yen.

As a culture the Japanese people do not like to get involved in the mechanical repairs of their cars. Mechanics can be very high priced for common repairs, especially to meet the "Sha-ken" standards. If you fail the "Sha-ken" then your car is de emed illegal to drive on the roads of Japan.

This has created a large industry of recycling the parts of these cars. The motors are typically low mileage, less than 30-60,000 miles, and have a great deal of serviceable life left in them. Almost all of the JDM engines are internally the same as in the US but some engines that can be used in the US may have a slightly smaller engine displacement, the changes are to meet the size (in CC's) requirements that Japan has set for additional taxes. This has little if any affect for typical applications in the US and other countries and may even increase the miles per gallon, due to slightly smaller engine sizes. Be careful some JDM engines may not have the provisions for US required emission control devices. You should consult with your engine supplier for more detailed engine specification differences to assure your engine replacement will operate properly and meet all emission requirements.


JDM Engines - How do I know if I will get a good one?

JDM engines typically have low mileage compared to here in North America. Wide open expanses of road to drive on and limited traffic as compared to the island of Japan, not to mention the culture of the car in America, give the Japanese engines a much less demanding environment. On the other hand, there can be engines that have resided in the heart of Tokyo and been idling along the congested roadways accumulating low mileage, but doing so in a very hostile environment of the city. Each engine should be carefully inspected for signs of wear and tear with the exactness of an automotive surgeon.


JDM Engines - What do I need to put one in my car?

When swapping in a JDM engine into a US based car, using the cars original engine management system, and accessories is recommended to ensure you stay compliant with all emissions requirements. This assures part availability at your local repair shop or part store.

Many companies will offer or even promote that they have the full harness still attached to the engine, this does not necessarily mean that it is better. Many of the components that are attached to the JDM engine are different than the US models.