What is the difference in a JDM engine. I know it is a Japanese Domestic Manufacture, but what are the benefits of the swap?

It has higher compression (10:1 I believe) and I think it also has a different intake manifold, iirc. These are good for another 10 hp. The JDM engine is rated at 150 hp. The advantage is you swap in a low mileage engine, with more power, for not a lot of money. Most people swap in a jdm when there engine goes bad. With most internal engine problems it is cheaper to get a new engine then fix your current one.

He is right on with all of that. The only thing is when I got my engine I had to use the old intake off of my old motor because of emissions or something like that.

What is interchangeable between the JDM and the US version?

Originally posted by mpg9999
It has higher compression (10:1 I believe) and I think it also has a different intake manifold, iirc. These are good for another 10 hp. The JDM engine is rated at 150 hp. The advantage is you swap in a low mileage engine, with more power, for not a lot of money. Most people swap in a jdm when there engine goes bad. With most internal engine problems it is cheaper to get a new engine then fix your current one.

Actually, only the Primera engines are 10:1 CR. There are many imported JDM engines that are still 9.5:1 CR.

The Primera engine is rated at 150ps. The ps stands for pferdstarke, the German equivilent of horsepower (and also what pferdstarke means). PS is calculated slightly differently from SAE hp, and a 150 ps engine is actually around 147-148 or so hp. Still healthy. For a conversion, to here:

http://www.repairmanual.com/unitconversions.html

Originally posted by jnk5y
What is interchangeable between the JDM and the US version?

Everything

Its not the intake manifold that gets the extra HP, its the exhaust manifold. The primaries are quite larger than the stock US exhaust manifold.

Also the JDM sr20 doesnt have the EGR system, so if you have emissions testing in your area, you will end up swapping manifolds anyway.

Here is a picture of the JDM exhaust manifold compared to my Pacesetter:

http://garnet.acns.fsu.edu/~sgg8661/engine04.jpg
Pacesetter on the left, JDM manifold on the right

How could you verify that the engine is or isn't a Primera motor? I need a new engine but I can't get a high compression one and stay legal for autocross.

Geo91SER is right. Only the Primera engnes have the 10:1 compression. Actually, it's the Primera 2.0 GT sold in Europe. Yes there is a difference on the exhaust manifold (bigger and no o2 sensor hole), and the intake is also different (at least on mine it was). Mine came with direct port ignition and none of the same emissions stuff that we have, so I had to use my old intake and exhaust manifolds (but got a Stillen header anyway).

Originally posted by Scarpa
How could you verify that the engine is or isn't a Primera motor? I need a new engine but I can't get a high compression one and stay legal for autocross.

The Primera engine has the tubular manifold.

If you want to stay legal, you will have to look for one with a cast iron manifold.

Don't forget to change intake manifolds to the USM one.

I swapped a JDM SR into my NX2000. I've been having problems with the temp sensor reading really, really hot, but really quickly. I've found out through a friend that JDM motors temp sensor sending unit (for the gauge) sends a different signal than our sensor is used causing it to read hot (as in overheating) while it is not to that level yet. Otherwise I bought my SR from SOKO and it runs really strong. Are you used to 2nd gear burn outs, cause that's what my NX is capable of now. It feels alot stronger in the other 2 US spec SR's I've driven.

try putting the US SR20 temp sensor in your new motor

can the primera header be modified to work with a 99 g20

It can be made to work with the G20 I would think because of the engine being an SR20DE. The problem is that if you find one without a downpipe you will have to spend more and get a downpipe fabbed for it and this can run you some money. I was quoted around $150 for a crush bent downpipe for the header. That is when I decided just to go and get an aftermarket header.

What about the egr system can that be modified to the primera header and will the primeraa downpipe work if i can get one of them

You will have to get the header modified at a local muffler shop fir the EGR fitting. Once that is done and the donwpipe is fitted then you should be ready to go.

How much can you get a JDM? How much for a DET? My car has 142K, so in a year or so I need to look at a new motor.

Originally posted by Ericdd
can the primera header be modified to work with a 99 g20

I was lucky enough to get the Primera header WITH a downpipe.
I sold it to SENTRASER. He put it on his NX.

I got a european 100NX GTi with 143 Hp and it has the same header as the JDM.

dont forget the passenger side motor mount bracket on the JDM engine is slightly different than the US spec.