What is a JDM engine?
JDM engines come from Japan, and are called JDM because they are manufactured for domestic use in Japan, hence "Japanese Domestic Market" engines. Some people replace the "Market" with "Motor", but in the end it's pretty much all the same.
Japanese Domestic Market -Why do we have so
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
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 deemed 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
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