This is to the experts out there:

Yesterday, Jim (wolfcri) and I went to Soen to pick up the motor for his blue NX. The warehouse was pretty jawdropping for since, since we've never seen anything like it. There were about 13-15 SR20DE's, and one S13 DET.

Anyway, we were just wondering what the differences were between some of the DE's. Some of the obvious differences were the valve covers. Some had a goldish hue, while some were more silvery. Some had black in the middle where the spark plugs go, some didn't. All of them, save for one, used to be hooked up to automatics, only one had the manual tranny flywheel.

I didn't get to study the exhaust manifolds that much because they had the heat shields on them. Otherwise, the shields looked pretty much identical--longer and less bent than the USDM versions, with a little vent on the shield right before the manifold connects to the downpipe.

And finally, Jim noticed one strange difference. On the left side of the head (if you were looking at the motor from the front of the car) there were "ribs" molded into the head. This was only on 2 of the motors, although only one of them had the silver VC with the black middle, and one was all silver.

We picked the one that had the ribbed head, all silver VC, and the TPS was a little different looking. Instead of the usual one brown clip, it was a bigger black plastic box with a bunch of wires coming out of it. It looked to be the "newest" motor there. We'll have pics posted shortly. . .

Jim paid $530 out the door for this beautiful motor :) Just one step closer to gettin the NX on the road!!

Chris,

Mine had the all silver V/C on it. I dont know about the McRibs:D . I'll have to look it over. It makes mad power though!!
It was also from an automatic. It was IMMACULATE when I got it!!

what do u mean by ribs.... i have a primera motor and it had the same funny tps with all the wires sticking out of it but i gotta check 4 these ribs u were refering 2

that funky tps is an automatic tps. it not only has a tps in it, it also has a bit of a pentionometer in it to gauge how quickly the throttle is opened. thats why there are 2 plugs, or about 7-8 wires coming out of it

On the size of the head that is exposed, on the side opposite of the distributor, it is smooth on the 4 USDM SR20's in my driveway, but the new motor that we just picked up has lines running down the side. It looks like it was an effort to add either more structural rigidity to the head or just to aid in air cooling? I have pics that I will upload once I get back onto broadband access.

Bowlcut, I thought it may be an automatic TPS issue, but none of the other auto motors had this kind of TPS. It was actually the only one there that had this type of thing. Like i said before, I'll have pics up in a few days.

ok, well i got bored so I uploaded the pics on my slow @$$ modem.

Here you can see the all silver VC:

http://www.tcnj.edu/~sysant2/dogs/cleanashell.jpg

Smoothy and DEAD SE-RIOUS: here is a pic of the McRibs :p
They are those lines between the 4 circles on the side of the head. Like I said before, only 2 motors in the warehouse had them, and none of the USDM ones I have seen have them.
http://www.tcnj.edu/~sysant2/dogs/headRibs.jpg

Bowlcut: here is the TPS:

http://www.tcnj.edu/~sysant2/dogs/tps.jpg

This motor is damn clean. We looked thru the #1 spark plug hole, and could read some of the numbers stamped on the piston. I remember reading somewhere that 10:1 motors have flat-topped pistons, but this one had a circular indent (a very very slight indent) on it. It looked so slight that you would just barely catch your fingernail on it. The one in my SE-R though looks completely flat, but not as smooth as the JDM one. Carbon deposits maybe?

The coolant that dripped out was pretty green, and the oil left on the dipstick was a healthy brown. The motor had NGK platinums (PFRBK11's or whatever it is), and it was pretty clean too.

Here are a few more shots of the motor: one on the skateboard that Jim and I used to wheel it into the garage, and another of it before we took it out of the van.
http://www.tcnj.edu/~sysant2/dogs/SR20skateboard.jpg
http://www.tcnj.edu/~sysant2/dogs/motorinvan.jpg

That is without a doubt a JDM motor. The IM has no provisions for the EGR or BPT valve.

Originally posted by NismoSER

Smoothy and DEAD SE-RIOUS: here is a pic of the McRibs :p
They are those lines between the 4 circles on the side of the head. Like I said before, only 2 motors in the warehouse had them, and none of the USDM ones I have seen have them.

i have two primera motors and neither 1 of them have those ribs i have everything else i have 2 check my other motor 2 c if it has the ribs

Originally posted by Nismo87SE
That is without a doubt a JDM motor. The IM has no provisions for the EGR or BPT valve.



Thanks Nismo ;) I already knew it was a JDM!

I have been told that the JDM motors with the black channel are 9.5:1 I have one like this and I was told by the man that it was a 9.5:1

I know for a fact that the UK SR20DE that brings the red VC very simillar to the DET VC is without a doubt 10:1

Originally posted by SE-Rican
I know for a fact that the UK SR20DE that brings the red VC very simillar to the DET VC is without a doubt 10:1

Finally someones brings this up. Thanks.
I have posted this to before.

anyone else??

only real way is to look down the spark plug hole with a bright flash light. if you see any indentation then its not 10:1. The 10:1 pistons are pefectly flat as I have seen them in person now. Looking down if you see any sort of ring or any thing that might look like its indented, then its not 10:1.

as for the black valley, most all 91s and 92s have a black valley, my 93 doesnt ***. then they quit coating the vc with that coating that really isnt all that much colored just turns more colored over the years. run a compression check if it specs out more than 178psi then you know its not a 9.5:1 motor.

The different about 1o:1 motor are the Valve cover and the distrubutor.

This a pic of the 10:1 motor in my car

http://www.imagestation.com/picture/sraid19/pc609f37da0230ca681aba224fcecdb35/fdc9d81b.jpg

i don't have those ribs but i did have the big tps i didn't notice any difference in the distribitor what exactly is the difference, cause ur motor looks exactly like mine

If you see any dish at all, you have a 9.5:1 motor

9.5:1 pistons
http://www.sr20deforum.com/eric/motor%20pics/DSC01848.JPG

10.1 pistons
http://www.sr20deforum.com/eric/oops/DSC01902.JPG

ah, eric. you are beautiful baby! That's what I was looking for. Thanks dude!

I didn't realize different # pistons would look different. I think it will be easier to see that heart shaped dish in the 2 & 3 cylinders. I'll check for those later, thanks again!

Originally posted by NismoSER
ah, eric. you are beautiful baby! That's what I was looking for. Thanks dude!

I didn't realize different # pistons would look different. I think it will be easier to see that heart shaped dish in the 2 & 3 cylinders. I'll check for those later, thanks again!
I tried removing the spark plugs on both the 10:1 compression on the race car and the 9.5:1 compression on the classic and I could not see much. The plug hole is too small to see what type of piston you have even with a flash light. Unless you remove the cylinder head, you will not be able to tell what compression piston you have. The search continues...

Originally posted by NismoSER
I didn't realize different # pistons would look different. I think it will be easier to see that heart shaped dish in the 2 & 3 cylinders. I'll check for those later, thanks again!

This is the first time I seen the heart shaped pistons and I have changed the head gasket on 2 SE-Rs and have opened up 2 of my own engines and never seen the heart shaped pistons, you can even look in a Nissan Motorsports Catalog and you won't see the heart shaped piston in there they have probably been changed by the previous owner and are after market.

my car has the same McRibs with 53 J heads on it...its a japanese bluebird if that helps any, but the TPS isnt the same though...