The pictures below are not my engine, but for illustration purposes. My truck had a 4.6 with secondary air injection (SAI). It now has a 4.0 block w/4.6 SAI heads and a non-SAI ECU. So my mechanic left the SAI gear in place, because he didn't know what to do about the holes left behind when you remove the SAI manifold. I'd like to remove the manifold and pump because they are not being used and it would make plug changes a lot easier if they were not there.

Does anyone make the plugs to cap the holes left behind if you remove the SAI manifold? I don't have access to a machine shop. so I'm hoping there is an off-the-shelf solution.

Thanks,
Tim

 

You should be able to install some kind of disc in place of the SAI tube, where the flange of the tube would normally go. Spray it with copper coat gasket spray before installing to help form a seal.
Are you replacing the ECU etc. so that the truck will work without SAI? It will throw errors if you don't.

 

My truck has the Non-SAI 4.0 Liter ECU and Fuel pump and runs perfectly. The only left from the old 4.6 are the heads. I just want to junk all the SAI equipment since it is serving no purpose anymore.

I thought someone on this forum did this mod before and had found some kind of pipe fitting (gas maybe?) that worked to plug the holes in the heads. I'm also wondering if any of the British Rover engine builders might offer something.

 

I think I remember reading about someone using nickels.

 

It's a pipe thread, and you can get plugs at a hardware store.

 

It's a special thread for the heads. I think it's 5/8 fine thread. The tool to thread a plug isn't worth the cost.

I welded the end of my SAI plugs. Here's a video of me welding the ends. I'm no pro welder but it didn't leak exhaust.

 

You have all the threads you need.
Since you're getting rid of the SAI and no longer need the parts, cut the nuts off the tubing. Leave the injectors in the head. Then find a metal disc of some kind that will fit inside the pipe nut and you should be able to seal up the injectors. No welding necessary.

 

Thanks Conrad. I may end up doing this as well. I'm looking forward to seeing my engine without all of that SAI pipework everywhere.

 

You're welcome TimInNova. Good Luck!!

Don't forget you can also get rid of the air pump on the firewall. Gives you lots of extra room in the engine compartment.

I sold all my SAI parts on Ebay. Make a few buck back in your pocket!! If the parts are in proper working order.

 

I spent hours going to every place in town including Fastenall and no one could match the threads. I ended up doing what Conrad1468 did - weld - grind pretty - put back in.