Heat Riser Removal

[dryheat]

I have removed the heat riser butterfly and shaft from the passenger side manifold and now am faced with filling the two holes. I have seen other posts on here about filling these with nuts and bolts but want to take a different approach.

I went and purchased a couple of different styles of threaded plugs and was hoping to get some input on which would be best.

Style 1 is a 1/8 NPT brass plug and style 2 is a 7/16 steel hex head plug.

By far the easiest to install will be the 1/8 NPT brass screw as the existing holes are already the correct size so I just need to run a tap in it. Using the 7/16 steel screw will probably require drilling the hole out slightly before threading it.

So I guess it comes down to whether the brass plug would be able to withstand the heat and if the expansion/contraction rates of using dissimilar metals would pose any potential problems.

Thanks ...

 

[1moreproject]

I tried this years ago and once I knocked the bushings out, the holes were too big for 1/8” NPT, I think I ended up using 7/16” bolts. Second time around I left the bushings in and used 5/16” stainless bolts. Installed with nuts and welded the nuts in place.

 

[Jim Bob The Dancing Bear]

I left the bushings in and had them welded up. Works great.