Has anybody ever used an 85 13b block with the S4 intake manifolds? I bolted the LIM on the block and cracked the bottom front (toward the radiator) right off. I swapped in a spare and broke that one too!! It seems like they don't want to mount flush. Has anyone ever done this or is it just me?

 

Keep your stock manifolds but use an s4 throttle body, adds a nice little kick.

 

I have an S4, and the stock S4 manifolds. I don't have the 85 intake though. So you're saying I have to find them....

 

You are doing something wrong.

The S4 lower manifolds bolts right to the SE engine with no issues. Are you sure that you are aligning and seating the 6 port actuator rods?

 

You cannot bolt a S4 throttle body to a SE manifold.

 

I'll be tearing into the engine again this weekend. I'll recheck the rods and check for anything else that might be getting in the way. Thanks.

 

Allright... got another problem. I noticed that the S4 manifolds differ slightly from the ports on the engine.

The picture below shows what I mean. I believe it is an S5 intake pictured, but my engine has the ports shown with an arrow, along with the large rectangular one in the center. The S4 intake has the lower ports, but not the rectangular one.

I tried to use the S4 intake and block off the center port, but the motor will not run. Any ideas?

 

If you are swapping intakes you have to swap everything--LIM and UIM, & TB. You can, however, use the stock AFM. You will have to buy the adapter at autozone. Unless you are up for a pretty intense project, stick with the stock intakes. Even if you do swap over to an S4 intake, you may be lucky to gain 5-10 ponies.

Mike

 

That sucks. I was hoping to just be able to use the SE lower intake with the S4 upper intake and throttle body.

 

Trust me, unless you are going to do a complete S5 intake swap and eventually use a stand-alone ECU, you are better off using the stock intake.

 

The ports you're referring to are for port air from the air pump/ACV to reach the exhaust ports. They're purely emissions related, and will not keep the engine from running. If the engine won't run, it's likely a big vacuum leak. Are all of your gaskets new?

The 13b block in a GSL-SE is nearly identical to the 13b in an S4, so I don't see why there's a problem mating the S4 LIM.

 

If you still have your heart set on doing the swap, just use the entire S4 intake. Like doc said, the S4 LIM will bolt right up to the SE block. There are slight modifications that need to be made, but it is very doable. Do a search, I think it was John 64, on S4 intake swap. I don't understand why you want to utilize the S4 UIM, but want to keep the S3 LIM? If you do the swap, you will be able to use the S3 AFM, but you must transfer your S3 TPS to the S4 TB. The S4 TB also uses the mechanical rod for the OMP, so you can make some bends in the rod to work with the S3 OMP.

 

Let me try to explain my setup a little better and avoid any confusion.

My car is an S4 non turbo. The stock engine died, and I did not have time / money for a rebuild, so I found a replacement engine, and paid next to nothing for it. I was told it was out of an 85 GSL-SE and that it would drop right in with no modifications. The "no modifications" part turned out to be a little more involved than I thought, but no big deal.

Currently I have the entire S4 intake/TB on the engine. It does bolt up perfectly, with the exception of the S4 LIM not mating up correctly. Everything else also matches up perfectly. Sensors, mounting brackets, hoses, everything. The only difference, in fact, between the S4 engine that I had and the SE engine that I installed were the engine mounts, which I have already solved. That and the LIM ports.

When I initially installed the engine, with all the S4 stuff on it, it ran fine, but had a vacuum leak and a fuel leak. When I tore it apart again to fix the leaks, I found that the LIM did not match up correctly.

I have already sourced an SE LIM/UIM/TB. If this is what I need to make this car run right, I will buy it.

I would be fine with using the S4 LIM, but what is that rectangular port in the center for? It seems like it is for exhaust because when I had the engine running, it was loud as hell and there was hot air blasting from that area. But I don't know really.

That is the situation. Based on what I'm trying to do, what would be the best setup for me to use?

 

Since you already have the parts, I would go ahead and use the S4 intake. The problem that you are having is that the LIM is sucking air. Within an hour, you can have the S4 LIM ready to go for your block with a few mods.

Here's a quote from a member that did the swap concerning the LIM:

"Please note that the lower intake will take some extra work to use it on the SE. You need to fill the secondary injector ports (JB Weld) It does bolt right up, but the ports do not exactly line up. There is a passage that sits directly behind where the ACV is on the manifold side. The SE’s use it to direct air in for the ACV and it sits a little lower then the housing. On the S4 it uses two side ports for the same purpose (I JB Welded these up even though you don’t have too). You have two options to solve this; either you JB weld this port opening closed on your engine block (I did not like this option) or you get a nice piece on angle iron (aluminum) and bolt it up to the bottom of the block to fill the void. I used some JB Weld just to make sure. Use a nice metal level to be sure your make all the mating surfaces flat."


Here is the link with all the pics:

https://www.rx7club.com/1st-generation-specific-1979-1985-18/s4-manafold-swap-complete-749845/

Also, check out this link:

http://max7.rx-7.org/mods/mod-intake.htm


These two links will answer all your questions, especially those concerning the S4 LIM with the S3 block.


Hope this helps,

Mike

 

Thanks for finding that. It's like a treasure chest, filled with all the information I need.

So basically the rectangular port is unnecessary, it just pulls air for the ACV.

 

As I mentioned before, the middle port on the S5 LIM and the two outer ports on the S4 LIM are for emissions only.

 

Well..... technically I should be worried about emissions in my area, but I'm not. I can get my car emissions exempt . Thanks for the info guys I'm gonna get to work on modifying my manifold.

 

Lol. You're right. You can't. I was thinking air flow meter, which does work. My bad, and thanks for the correction.

 

You are 1/2 correct here. Some have tried to use the S4 AFM on the Se but have never got it to idle correctly. This was only achieved by removing the guts of the S4 AFM and replacing them with the SE internals.


As far as the original poster goes.

You are getting your self into some unneeded mods here.

You do not want to run the SE intakes and T/body with your S4 ECU. It will not work properly . The SE intake and T/body flows a lot less air than the S4 does and also the fact that there are only the provisions for the 2 injectors in the engine on the SE. The S4 ECU is mapped for 4 injectors not the 2 large ones that you will only be able to use if installing the SE manifolds.

You can also just put some aluminum foil in the emission opening of the SE engine and if you want put some exhaust putty over the top of the foil paper to seal the exhaust leak there.

Stick to the S4 components in your S4 ECU controlled vehicle.

 

Thats what I had planned to do all along. I actually have solved the port problem by modifying my S4 lower intake.

I used a combination of JB weld and qwik weld putty to add an extension where the port would be. This, combined with a gasket, will block off the unnecessary port.