I am finishing up the cleaning/polishing process of my s5 intake for my 87 gxl. I wish I had a camera to take a picture of what I broke. On the LIM, the part that bolts to the block, there are 2 grooved shafts that flex inside the manifold. I can't figure out what to call them. They are hooked up to the port actuators ( I think). Basically, if you wanted to mill yer manifold, you couldn't because these extend beyond the surface of the manifold. I broke off the part that I think causes the port sleeves to open. Looks like whoever had it b4 me was trying to unstick them. I can barely rotate one with a screwdriver wedged between the fork on the end of the shaft. The other one is broken off. I cant see that vacuum operated actuator rotating these shafts with only 1 or 2 psi. Should I be able to rotate them easily?
I unbolted the broken one to see how to get the rod out of there, but I think that it may be pressed into it. I checked my haynes book but no info. Sorry this got kinda long. Thanx for reading.

 

These are the Aux port rods you are talking about right???

They should slide and move easy. You may need to soak them with liquied wrench or WD-40 over night to loosen them, if they are gummed into place.

 

thanx Mark,
the ecu I bought from you works great by the way. I have lights and buzzers that I never knew exsisted.
yes, that must be what they are called, what do I do with a broken 1? the very last inch of one is broken off.
please help?
can I use my '87 lower intake or is the whole reward in this swap from the LIM?
are these rods pressed in?
I'll start soaking now.
thank you

 

On a S4 engine I would be using the S4 LIM and the S5 middle/VDI and upper sections.

It will require some minor drilling, and using a S4 gasket, but you don't have to worry about the port air situation and manifold to engine differences.

Drilling the middle/VDI section to mate with a S4 LIM:

and a little bit of grinding (you can see the nut that needs to go on, in the lower left corner of the pic):


S5 MIM/VDI, bolted on to S4 LIM:


Glad the CPU works great for you! Keeping one more 7 on the road

 

thanx again Mark
should I even unbolt the S4 LIM off the car? I am sure the ports are opening? Will I achieve the same amount of gain?
thanx

 

ok, I don't know how to remove a post, but after looking at Marks pics, I see that I HAVE to remove the s4 LIM to figure out where to drill/grind/etc......

 

Yeah, I actually had a spare N/A motor that I could fit it all on to test fit. But you could drill the S5 MIM/VDI with just a S4 LIM to MIM gasket

On your existing motor, do the aux port shafts move freely?

 

I haven't gotten that far yet. I have ported things a wee bit and polished (looks great) everything. Then I broke a rod. Oh well, it is very nice to find out that I can use the one that is currently on the car.
thanx

 

Yeah, it makes it much easier.

The S4 LIM:


Compare that to the S5:


See the port air holes are in the wrong spots. So if you use the S5 LIM, then you have to fill in the port air on the S5 LIM with epoxy:

 

thanx, so should you be able to grab those aux port rods with yer hands and turn them?

 

hey mark,
in yer very first pic, just to the left of yer drill bit, inside the port is a little filter thing. As you know it comes out, what is that called? I broke one of those too. Not my fault.

 

They are called Injector Air bleeds. The ones in the VDI manifold are Mazda P/N 13-C600-N351 and are usually around $20 USD.


They just push in and out. You will want to remove them if you port match the manifolds, and then put them back in before final assembly.

 

I take It you researched all the Implications associated with the s5 Intake > s4 Motor? I was very close to undergoing this way back when until I learned that you actually lose HP before you gain It back.

I'm not trying to rain on your setup but this thread maybe of some Interest to you. Although others have had some success. https://www.rx7club.com/showthread.p...ghlight=intake

 

The HP loss is pretty minor, and mostly related to the S5 intake being slightly smaller.



When I did mine I had the S4 LIM, and S5 VDI/UIM extrude honed and matched so that the S5 UIM and VDI section was much closer the S4 sizing and volocity.

with RB headers, midpipe, TB mod, electric air pump (of course Carl has his VDI set too high (it should be at 5200), and questionable aux port operation (which further reduces low end... and the dyno sheet proves that) On top of all that, he is using the S5 LIM setup instead of the S4-S5 combo setup:


I'll post my dyno stuff up next week.

 

hmmm, thank you for the info guys. I really love this forum. I indeed have done a bit of research. I like the look of that top end. This is a 4th car so my wife and I think that this will become the drag car (just for fun). I live about 10 min from a dragstrip. I think that I will go for it, if not only for the experience. I am new to these and learning more and more every day. thanx
greg