japenese and american engines differences, take a look (pics)
 

Hey guys, one of my friend blew his engine so he bought an engine from a used japan engine seller and finally, the engine was blown. He offered the guy to buy it anyway so he let it go for 400$, it included the tranny, all manifolds, turbos, harness, everything. So 400 is a pretty good deal :D.

Anyway, I went to his place to help him remove everything on the engine and trying to make a good one with the two engines that were blown. Now what I found is pretty weird, the engine really is from japan, it is not an engine from america. Here are the funny things i found and I wanted to share. Some of you might already know this but I thought it was interesting for someone who had never seen a japanese engine and know what an american one looks like. It is a 1997 he was told. Here are the differences I found.

Sorry for those who like me have a slooooow speed connection.

First, here is the rat’s nest, for those who have seen what our rat’s nest looks like, you can see that mazda made it clearly better in the newer years

https://www.rx7club.com/forum/attach...postid=1413549
https://www.rx7club.com/forum/attach...postid=1413534
https://www.rx7club.com/forum/attach...postid=1413516
https://www.rx7club.com/forum/attach...postid=1413556
https://www.rx7club.com/forum/attach...postid=1413562

Now here is the lower intake manifold.

Red circle: you can see that in the japanese one, there are no nipples for the vaccum to go to the other side.

Blue circle: you can see that in the japanese one, there are no EGR

https://www.rx7club.com/forum/attach...postid=1413585
https://www.rx7club.com/forum/attach...postid=1413592

In this pic, you can see that the air tube for the main cat is not made the same way, it is in a different angle

https://www.rx7club.com/forum/attach...postid=1413597

Here are two pics of what they did to pass the vaccum on the other side of the lower intake manifold. Instead of going through it, they decide to go around it. I don’t know why but… this is what they made.

https://www.rx7club.com/forum/attach...postid=1413610
https://www.rx7club.com/forum/attach...postid=1413613

Here I have a question, what is that thing on top of the injector? The american ones don’t have that. It looks like something to adjust them???

https://www.rx7club.com/forum/attach...postid=1413571

Here is the upper intake manifold

Red circle here shows that there is no nipple for the AWS (accelerated warm-up system) and that there is no solenoid

Blue circle show the location of the purge control solenoid. On our cars, it is not located on the upper intake manifold.

Yellow circle shows that there are no pulley for the cruise control. Although I ain’t sure if this is japanese specific, someone correct me if I am wrong, I have only seen FD with cruise control so far. It is also gold instead of green :D

The green circle shows that there are no nipples for the vaccums in front and there is no place to connect the PCV valve (like the 95 version)

https://www.rx7club.com/forum/attach...postid=1413628
https://www.rx7club.com/forum/attach...postid=1413643
https://www.rx7club.com/forum/attach...postid=1413647
https://www.rx7club.com/forum/attach...postid=1413652

Here you can see what the coils look like. I don't have a pic of the american coils in hand but the one where there is two place to connect the spark plug wires is in the middle on the american version. Also, there is a sort of bend that we can’t see very well on the pic but the one on the right is not at the same angle as the other ones.

https://www.rx7club.com/forum/attach...postid=1413601

This is the stock japenese downpipe (lower one) The one above is an aftermarket downpipe. You can see that they had no pre-cat in these years.

https://www.rx7club.com/forum/attach...postid=1413659

Si finally, i guess there wasn't much emission related stuff after 95, no EGR, no pre-cat so obviously no AWS.

Anyone can explain this? Did they find a beter way to do emission after 95 or are emission tests easier in Japan?

Nice info man. 2 thumbs up :bigthumb: :bigthumb:

It's nice to get information like this. The pictures were great. I'm totally amazed at the "rats nest". I wonder if the newer integrated unit is backward compatible, and if so, can it be purchased here in the states? If it's available I'm getting one.

Again my compliments to your effort. :D

I have heard someone say that their US FD dash pot was gold. Pretty cool stuff, though. Very informative.

well this rat's nest is for sale if you want to try to fit it in your car :D

i am sure is goes really well, just need to find which vaccum goes where... But i ain't sure the harness will fit though if you look at the way they plug in it.

i knew some would like to see that, i though it was cool ;)

Lokking at the pictures, I am guessing the way it was originally mounted with the plugs and the vacuum nipples facing up. If it can be mounted on the side then the plugs can be manuvered to fit.
The problem is can individual solenoids be replaced? and can we access any information on a vacuum diagram for that vacuum control assembly (VCA)?
How much do you want for it?

i have no idea if the solenoids can be replaced and i really don't know where you could get the VCA. I guess a japenese dealer might be able to get you one or someone in japan that has a 96+ FD with a manufacturer manual.

i have no idea how much it is worth, what is your offer?

Actually, it is not mine so i would have to ask the owner if your offer is enough.

puma

There was a post about the updated "rats nest" on the Big List a few years ago. I'm sure it's archived somewhere, probably on Steve Cirian's Lightning in a World of Thuder site. I don't remember all of it, but what I do remember was that US 93-95 FD's could not use that updated rats nest due to differences in ECU control for it. Very nice pics though, it's cool to see the differences. BTW - My 93's dashpot is gold colored.

I've heard of the different rats nest. Man I wish I could run that in my car instead of the crap Mazda put in there.

Thanks for the very detailed pics and info!

Jeff

Dam...was this a nice write up or what...very informative Puma. I will be using to picks when I take off my UIM. THanks.

Very nice write-up:bigthumb:
thanks.

ed

my pleasure guys.

so anyone know what that thing on the injector is for?

also, are non cruise control FD having the two pulleys on the throttle body actuator? anyone has an RX-7 with no cruise control?

puma

All the R1's and R2's came with no cruise control.
I have an R1 but I can't answer the question.

Edit: Looking at the pic of the throttle body, I can tell you that my R1 has pulleys where you drew the yellow circle.

yeah and i have an R1 but it is a 15th anniversarry so i have a cruise control... :(

Cool post Puma

The Japanesse don't have emissions like we do. Where they get nailed is on inspections. They are so costly and intense most people dump the car ... one reason we get parts with 40k miles on them.

Another thing to think about with the rats nest in a box and a Japanesse ECU .... well they get a 16 bit ECU stock. :) I bet that one doesn't have a 3k hesitation. Interesting stuff, but years too late. With the PowerFC, block off plates, you can make our cars just as simple, if not simpler, and run just as well (16 bit PowerFC).

US R1s came with the "pulley" for cruise. I've had 4-5 of them and they all had it:).

As for a thought on getting that new "control box" to work. If the engine came with a complete harness you could probably get a PFC from someone overseas for the later car and get it to work, maybe?

Jeff

Damn nice pics and post, Puma! Thanks!

i am going to copy this to archives. :)