Intake manifold question
Thread Starter
Junior Member
Joined: Aug 2012
Posts: 49
Likes: 3
From: usa
Intake manifold question
My stock 1980 has only one modification that I made to the setup, years back I replaced the thermal reactor with a 1981 exhaust manifold, while I remove the air pump and the other equipment that was no longer needed. Recently while I was stripping down the rats nest and following the post for stripping the Nikki carb, I removed the intake manifold to replace the gasket and plug the coolant connection to the intake manifold. The center ports for the intermediate housing has a rectangular opening below them. What are these for? I see on a 1981 series that the intake manifold is different and has a full gasket around the rectangle, I know that 1981 no longer had the thermal reactor, but on my1980 I can not find any information on this opening. And since I am the original owner, I do not recall ever having any connection to this opening. Attached is a picture of my setup.
Pack that port with quicksteel or JB weld's Steel Stick
Use about 1/3 of the tube or so. Also make sure the port is clean as it is usually lined with carbon and a little bit of oil as it is in direct communication with the exhaust ports.
On yours maybe don't worry about it if it has always been open.
Use about 1/3 of the tube or so. Also make sure the port is clean as it is usually lined with carbon and a little bit of oil as it is in direct communication with the exhaust ports.
On yours maybe don't worry about it if it has always been open.
Thread Starter
Junior Member
Joined: Aug 2012
Posts: 49
Likes: 3
From: usa
Thanks for input
thanks for input, I will look into blocking this opening, since I have been chasing an exhaust smell for a while. I just think that something must have been connected to this opening at some point but I no longer have the thermal reactor and other parts to verify this. I was thinking of using the plugged ports on the intake to hold a angled bracket against the opening and put a gasket to seal it.
Thread Starter
Junior Member
Joined: Aug 2012
Posts: 49
Likes: 3
From: usa
Still not sure about opening
So I was getting ready to block this opening, but I saw on YouTube a video on removing the intake manifold from a 1980 RX seven and this one still had the thermal reactor on the exhaust ports after viewing this video I saw the same opening was present when the intake manifold was removed. I beginning to think that this opening connects to nothing and the cutout was just planned for the next model year. Anyone have any thoughts on this?
Trending Topics
Only on certain models. Mazda was jumping through a lot of hoops back then to meet CA emissions requirements before they went with a cat system for 81 and later. The easy way to determine this is if your rotor housings have the thermal reactor-only ports that the 81 and later ones lacked. These ports are drilled at a steep angle.
A quick rule of thumb is if your housings have these steeply drilled ports, you are most likely not going to have a connection with the ACV port in your intermediate plate. That means you will not need to worry about filling it with quicksteel.
A quick rule of thumb is if your housings have these steeply drilled ports, you are most likely not going to have a connection with the ACV port in your intermediate plate. That means you will not need to worry about filling it with quicksteel.
Thread Starter
Junior Member
Joined: Aug 2012
Posts: 49
Likes: 3
From: usa
Very good information
thanks to Jeff 20B, I for sure have the thermoreactor ports on an angle. When I replaced the thermo reactor with the 1981exhaust manifold I did be sure that the gasket and manifold covered all of these holes.
Thread
Thread Starter
Forum
Replies
Last Post
Elysian
1st Generation Specific (1979-1985)
12
Feb 9, 2004 06:11 PM
whofarzed
1st Generation Specific (1979-1985)
20
Jul 28, 2002 10:28 PM