Anyone have to "clean up" BBK headers

Several guys over at the modular side have reported needing to do minor work like this to their MAC headers. Apparently burrs and rough spots near the welds are pretty common.. but I certainly would not throw on a set of headers on my car without verifying that there aren't metal shavings or anything about to break off.

I would think as long as you don't dremel past the welds, you wouldn't hurt anything.

I had a piece of migwire just dangling in mine when i got them. I cleaned mine up before i put them on

I cleaned up a set with a Dremel years ago. Took a couple of hours for both headers. No clue if it helped but I felt better about it.

I do them on all the cars I put them on and yes it makes a huge difference. Clean the welds on the primaries, then install the exhaust. Run it a few days to make sure it doesn't rattle or leak, then drop the catback and H pipe out. Take a dremel or die grinder and open up the ball flanges where the black soot shows excess metal. Usually the outlet on the balls are only a little over 2". Opening it up to 2 1/2" increases the flow and sound quality.

Jamie

yes "cleaning up" the headers make a drastic difference, A rough transition into the headers creats a turbulance witch decreases horsepower.The exhaust is not exiting the cylinder as smooth as it should. I have a personal experience with this a garage i hang out at have tested this theory before.We port matched or "cleaned up" the inside of the flanges of a set of bbk 1 3/4 longtubes (witch were really choked up) and used high temp sealer as a gasket , cut the ball flanges off the collector and tig welded on the 3 bolt setup and as a result of this we recieved a total of 11ftlbs and 16hp to the wheels in the peaks. Test engine was a 306 with JE 10.5 to 1 compression with a set of out of the box 185 afr's. So i really believe that "Cleaning the headers up" makes a huge difference it is worth the 2 hours you are spending on them for a couple ponys to the ground. thanks
Tim

I have read testing like that in one of my Mustang mags but it has been a few yrs back. My FRPP's weren't to bad but we did open the collector end up a as well as cleanded up the head ports.

I cleaned out my MAC shorties. Welds were fine but the protruded into the port so I smoothed them out so they were flush.
maybe took off 1/8" or so.

I clean them up when I install them at work....I also clean the welds on the tube to flange weld

yeah thats what I used. Just get a high speed cutter bit for it and a cone shaped sander. like these

i would clean them up for sure, anything thats going to hinder the flow is going to rob you of power, even if its only a few hp, i think its worth the time, best thing to do is find acess to a welder or someone who can do it for you, that way if you go to deep and cause a leak you can patch it up and re-do it, just my $.02

that first cutter works great, just spray /w water to help cool it and take brakes. I smoothed the bit out after using one to port the opening of myintake to 65mm... too much heat.

Make sure to get the Tungsten Carbide bit. Works better than anything else. Cuts pretty easily. But let the bit cool every minute or so.

I really wouldnt wory about going through the tube, causing a leak. Just take a little off at a time.

Use a light oil to cool the bit instead of water and let it cool every once in a while and it will last a lot longer.

onefstsnake said:

Make sure to get the Tungsten Carbide bit. Works better than anything else. Cuts pretty easily. But let the bit cool every minute or so.

I really wouldnt wory about going through the tube, causing a leak. Just take a little off at a time.

Click to expand...

its not hard to go to far on some brands, i was doing a buddy of mine's hookers for his craparo and ended up breaking through, sometimes there isnt as much weld there as there should be