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I'm green as grass when it comes to working on rotaries and could use some advice on a few things
Firstly, I have a 1980 Rx7 LS with the stock 12A engine.
I planned on removing the stock reactor in favor of some nice headers.
I'm attempting to remove the stock manifold and I'm running into a situation where I can't get the final upper manifold bolt out. The intake manifold is blocking so much I just can't get anything on the bolt head. I have the other bolts removed. Thankfully (or unfortunately depending on how you look at it) my OMP was leaking due to the hose falling off and so all my bolts are covered in decades of oil and thus they all came out pain free
surely there has to be a way to remove the upper rear bolt without removing the entire intake manifold...RIGHT??
any suggestions?
I can tell you I've tried just about everything. socket with a swivel neck and extension. Crows foot. I tried an offset boxed wrench.
Nothing can get into that little space. I can get a socket on the bolt head but there's no room for the swivel attachment to fit on there.
I really don't want to remove the intake manifold if I don't have to. I heard coolant runs through it and I have really bad luck with messing with the coolant systems on just about every car I've ever messed with... I would not feel confident in my ability to get any trapped air out of the system once it's buttoned back up
You should be able to get it off without removing the intake. It was so long ago when I removed this I can only refer to some old RE instructions that I have from my first aftermarket header/exhaust. In that document they just say to use a swivel head 14mm socket or equivalent. If you can get the socket on there, then you are halfway there. You could try bending an extension to get on it. Another option is to bend a 14mm wrench. Either way once you get one of them on there, just tap the wrench with a big hammer. You just need to get it loose. Heat and penetrant might help as well.
Last edited by t_g_farrell; Apr 2, 2026 at 02:58 PM.
Will removing the air control valve help?
My memory of the stock setup is getting fuzzy, but I do remember it was easy to remove on FBs, not sure about SAs.
What color is your car? LS's only came in White, Black and Gold. Thousands of heat cycles have probably corroded it together. I'd soak it several times with PB Blaster over a couple days. Can you get a socket and cut it down to make it shallower? If the socket fits further on will it provide any more clearance an extension? Have you tried a wobble extension?
1/4 drive tools can get into tighter places but you need to be careful not to over stress em to the point of failure. This is where quality tools come in handy.
You should be able to get it off without removing the intake. It was so long ago when I removed this I can only refer to some old RE instructions that I have from my first aftermarket header/exhaust. In that document they just say to use a swivel head 14mm socket or equivalent. If you can get the socket on there, then you are halfway there. You could try bending an extension to get on it. Another option is to bend a 14mm wrench. Either way once you get one of them on there, just tap the wrench with a big hammer. You just need to get it loose. Heat and penetrant might help as well.
I'm going to try a shallow 10mm set I'm picking up at harbor freight today! It's a bugger to get in there. Here's hoping it all goes well. I'll report back with what happens
Originally Posted by j_tso
Will removing the air control valve help?
My memory of the stock setup is getting fuzzy, but I do remember it was easy to remove on FBs, not sure about SAs.
Yes I removed the air control valve. Currently deleting my air pump and valve. I don't even think I could get at the bolt period if it was still on to tell you the truth
Originally Posted by Banzai
What color is your car? LS's only came in White, Black and Gold. Thousands of heat cycles have probably corroded it together. I'd soak it several times with PB Blaster over a couple days. Can you get a socket and cut it down to make it shallower? If the socket fits further on will it provide any more clearance an extension? Have you tried a wobble extension?
1/4 drive tools can get into tighter places but you need to be careful not to over stress em to the point of failure. This is where quality tools come in handy.
My car is black. Someone painted over it with blue rattle can. I know it's black because one of my LS badges fell off on the passenger side and it's black under the blue paint that's flaking.
Driver side still has the badge. Carpet and interior is also brown. Although someone replaced the seats at some point with a later model black pair. Guess they didn't like all the brown
And yeah! Instead of cutting up my good sockets I'm going to see if I can get a shallow socket set at harbor freight. I'll report back soon... Also the swivel socket I have is kind of long compared to some nicer ones I could probably save 1/4 inch on a quality set. Here's hoping
Harbor Freight sells Snap On? Thats the thermal reactor hanging off the exhaust ports. Any plans for the 2 sleeves that go into it? I'd be interested in obtaining them if your just getting rid of it.
It's more than just an exhaust manifold - it's a thermal reactor designed to recirculate air through those air holes in the circumference of the downpipe, and the cast iron assembly retains enough exhaust heat to burn off hydrocarbons and any oxides. As a simple chemistry fix, the reactor works well for what it is. You mentioned the weight, and when compared to a quality header and collector, the weight savings is substantial. Also, the flat mount plate of a header is FAR easier to manage the nuts and washers to mount it properly.
Harbor Freight sells Snap On? Thats the thermal reactor hanging off the exhaust ports. Any plans for the 2 sleeves that go into it? I'd be interested in obtaining them if your just getting rid of it.
Oh.. my apologies it was ICON not snap on both stupidly expensive
My plans where to set everything aside and sell them on eBay for cheap, feel free to DM me I'm happy to send em.
It's more than just an exhaust manifold - it's a thermal reactor designed to recirculate air through those air holes in the circumference of the downpipe, and the cast iron assembly retains enough exhaust heat to burn off hydrocarbons and any oxides. As a simple chemistry fix, the reactor works well for what it is. You mentioned the weight, and when compared to a quality header and collector, the weight savings is substantial. Also, the flat mount plate of a header is FAR easier to manage the nuts and washers to mount it properly.
Wow that's actually pretty interesting. I'm assuming that's all for emissions
Kind of crazy. This car is way before my time, I wasn't aware they cared that much about the environment in the early 80s
I planned on cleaning the engine up real real good. Painting it and sticking racing beats exhaust kit on there. it's hanging from a single hanger + off the studs soon as I pulled it off the entire exhaust system basically fell off the car and onto the floor makes the removal easy at least! .. sadly all my rubber hangers are ripped and replacement hangers are kind of steep price
While I'm on this topic, I have a question. There's a small flexible tube that runs from what I believe is the CAT up to the intake manifold on a very small connection point. With two bolts
If I remove this do I have to plug this opening? Surely that would be a vacuum leak but with it being connected to the open exhaust surely there was no vacuum for it to hold.. right?'
While I'm on this topic, I have a question. There's a small flexible tube that runs from what I believe is the CAT up to the intake manifold on a very small connection point. With two bolts
If I remove this do I have to plug this opening? Surely that would be a vacuum leak but with it being connected to the open exhaust surely there was no vacuum for it to hold.. right?'
I believe you are referring to the air pipe that runs down to the heat exchanger. Yes, you can use a block off plate at the rear of the intake manifold.
I believe you are referring to the air pipe that runs down to the heat exchanger. Yes, you can use a block off plate at the rear of the intake manifold.
Thanks for the link !!
And I figured as much... Currently blocked off my ACV after removing it along with my air pump.
Here's hoping that freed up a bit of parasitic draw
I was looking at it. I didn't figure it was worth it considering my engine isn't Ported
Did you go this route? I'm curious how it performs
Do you know how much power it adds? RB says some crazy 20% figure at 6000+ rpms which I find hard to believe
The RacingBeat estimate is pretty valid. At one point my car dynoed with a Dellorto DHLA 48 carb on it at 134WHP, which is probably the max HP out of a stock port 12A. I swapped in a modified Nikki but have no dynos or timings with it. Feels about the same. I'll be putting the Dell back on soon as prep for another project.
