Since I don't seem to be having any luck in the 2nd gen section. I will ask here.

Do these look like good used housings?

Link to Pics

Just want some honest opinions from people who know rotaries. Thanks

 

Those look excellent, nearly new.

 

One's an S4 and the other is an S5. Shouldn't be used together.

 

It's hard to tell from the pics but is the brown stuff just cumbustion residue? It almost looks like surface rust from degraded chrome. I have some used housings I got from someone else that have bad chrome and look alot like that.

 

What makes you say that, neither of them have the knock sensor hole...

Accourding to banzai racing's housing identification page Here
They are both s4 T2 housings. Can someone confirm either way?

 

The only thing I can figure is because the one pic makes it look like the leading plugholes are in different positions. I figured it was just the camera angle, but he may be correct. You're going to need to eyeball them yourself side by side to see if the leading plughole is the same distance from the trailing (or measure). By the look of the housings both should be series 4; I have never seen a series 5 without a knock sensor casting.

 

i agree the one on the left looks like the plug holes are farther apart

 

I think they look the same. How many mm is the difference etween s4 and s5?

 

I guess I will just have to wait and see when they arrive. I only paid $200. So if worse comes to worse. I can sell the one that doesn't belong and get a matching one. They look the same distance apart if you measure but if you look at the outside of the housing they are clearly different. Maybe different years I.E. 87 and 88??

I don't know but the motor that came with my car had chunks of rust on the spark plugs when I pulled them. So I am just trying to collect the parts to build a new short block.

 

The one on the right has the flat side on the leg. It also looks like the spark plug holes are higher on the side. That would indicate to me it's an S4 housing. I should of said it "appears you have two different housings".

I've seen flat side legs with plug holes in both the S4 and S5 location. But all the round side legs are later housings with the later plug holes.

 

So what does that mean in plain english? I am rotary language illiterate.

 

IMO the one on the left is an S5+ housing. Though it's odd that it doesn't have a knock sensor hole. I thought all of them, including the NA housings, had one.

The one on the right could be an S4 housing with the spark plugs in the different position.

Sit them side by side. The difference is obvious.

 

I figured out what you meant about the flat side leg but in this picture there are several of housings with rounded legs and no knock sensor hole.

I guess I can just pray it was the camera angle that makes it look that way.

 

The one on the right is a very early S5 housing, without the knock sensor hole. It has all the other characteristics, thicker eyebrow over the trailing, diff 13b mazda logo, and the edge on the leg.

 

So they made S5 housings without a knock sensor hole?!?! According to the guy I bought them from. They both came out of the same engine. Which was a Mazda remanufacture.

I just realized that one of you is saying the one on the right is an S5 and the other is saying the one on the left is... You people are trying to confuse me aren't you. This is all some sick game. I'm going to cry if you don't stop.

Seriously though, the current motor in my car (87 tII) has housings that match the one on the right with the flat leg and raised eyebrow. So like I said earlier I am going to wait for them to arrive. Measure, eyeball or whatever it takes. Then if I have to I will just sell the other one.

On a side note, only 1 of you answered my original question :P

 

I should not have posted before coffee. I just checked our inventory of housings and found that both S4 and S5 switch back and forth with the eyebrow thickness and the logo. I even have some early S5 housings without the knock sensor hole, but with the flat spot on the leg. All my FD housings are round leg as well as all my early 84-85 13B.

The only real way to check is the plug location. The chart on our site is only a quick reference guide for a majority of the housings

 

I still say one is a s5 and the other is s4 for sure.
and since the original question was already answered I didn't answer it again.
but if it makes you feel better they look to be in great shape and for want you paid
you got a real deal even though they are not from the same year.
Matt

 

Thank you, that does make me feel better.

 

Well I got the housings and they don't match so I need help identifying them. Measuring the inside edges of the spark plug holes I get1 and 1/2 inches on one and 1 and 3/4 on the other.

Help Mr Wizard I don't want to be here anymore.

 

If this is an NA engine, then it doesnt really matter. If it's a turbo engine I'd be pretty hesitant, but if you're not going for high boost/high power it should still be fine. I have seen a few engines run this way and no one ever knew until I examined it closely once it was out of the car.

 

I just noticed on top of one of the housings it has a raised N318. On mazdatrix website they have 89-91 housings with N318 in the part number. What bugs me is it doesn't have a knock sensor hole. So I have no idea what it is.

This is for a turbo motor. For me 1/4 of an inch is a pretty big timing advance...or retard.

Is it truly possible to have a Series 5 without the knock sensor hole??? Also are the s5 plugs closer or further apart than the s4???

 

The advance/retard has not changed, just the plug location within the combusion chamber. When the rotor is at X degrees of rotation, the plug may be physically moved slightly, but the computer handles the actual firing/timing. Think of it as moving the plug location in the head of a piston engine. Not changing timing, just location.

s5's have the leading hole lower.

I have never seen an s5 housing of any kind without the knock sensor hole.

By your description these were probably from a jspec, and were in the same engine.

 

According to the person I got them from they came from a mazda remanufactured engine. Everything points to it being an S5 housing except the missing knock sensor hole. As for my mention of advancing retarding the timing. I guess I don't fully understand rotary engines. I was just thinking it would be like the plug fireing later since it was further along in the housing (even though it fires at the same time).

If you say it will be ok then I will use it. Otherwise I am going to see about getting another S4 housing.