Guides How-to Core Your Exhaust

Ok, here is a how to core your cans my way, did them last weekend, so here we go.

First remove cans carefully and use a 6mm drill bit to remove the 15 pop rivets in each can, this includes the one on the mounting strap, you will need good sharp drill bits and probably about 4 off them, the rivets are sore on them, just drill the rivet tops off and the rest of the rivet falls inside the can, they will be removed later.

once all rivets are removed the next step is to remove the link pipe end, i used a large screwdriver for this, but i would use something a bit less prone to mark the metal.

I would like top point out that as my cans were for a track bike i was not to worried about some scratches or marks etc., so it is worth taping up the can sleeves with duck tape or similar to protect them from marks etc

Once this is removed you will see the cat (honeycombed part) which is a pain to remove, the platinum is bloody hard stuff

To remove the cat i used a good sharp cold chisel and went round the edges and went deeper and deeper with the chisel till the cat broke away from the casing, clean the inside of the casing to remove most of the platinum as this is where your core will insert.

this is the cat removed and you can see the inside of the casing

Next step is to remove the end cap the same way, the end cap has all the silencing core attached to it, this will come out in one piece when the end cap is removed

Now remove all exhaust packing and put to the side, don't destroy this as it will be used again
Warning-the packing is nasty stuff, wear gloves and a mask as this stuff will go for you

at this stage you should have this

now for the cutting, the end cap has to be cut from the rest of the silencing core, you need to cut at the back of the weld (towards the rear of the can), you should cut at an angle as can be seen from these pics

what you need to end up with is the end cap removed as can bee seen here

once this is done you will need to tidy up the end cap edges so it is neat and not covered in sharp edges, i used the die grinder and a dremel to finish it off.

You should now have the link pipe, the clean end cap, two straps, the sleeve and the packing.

Next stage is to drill four 3mm holes in the sleeve where the cat came out of, the new core slips in here and i attached it with 4 small self tappers as can be seen here

the new core has to be cut to size for the can and will also need to be cut at a slight angle to fit neatly into the end cap, there is a bit of trial and error required here to get the correct size for the new core, the new core should fit snugly inside the end cap spout, you might need to grind away small bits of weld inside the spout to allow the new core to fit as it is a tight fit, this becomes apparent as you do the job.

I did all my cutting and put the whole thing including the sleeve together a few times to get the correct length for cutting the new core, as i said trial and error here and patience.

Once i had the core cut and fitted correctly i then wrapped the old sheet of packing round the new core tightly and used a fine copper wire to bind and hold in place as can be seen here

next stage is to wrap the new packing sheet round the old stuff you have just put on, again wrap tightly and secure with a fine wire or similar

now slide the sleeve back on and centre the core so that it will fit inside the end cap, if you have gaps in the sleeve you should pack them with packing

and then push the end cap into place making sure the core is fitting snugly inside the spout as can be seen here

now you need to make sure the sleeve is seating and lining up correctly with the holes in the link pipe end and the end cap itself, once this is good then slip on the strap and start fitting your new rivets and then remove your protection tape and admire your handywork.

Fit them to the bike and be prepared for some music

Notes on tools required for the job, Drill and bits, die grinder, pop riveter, rubber mallet, claw hammer, pliers, screwdrivers, cold chisel, good gloves as there is a lot of sharp metal at stages throughout, goggles, dremel if you have it, it is handy for cleaning metal up etc., duct tape and patience.

Parts required, i bought two cores at 600mm long by 2.5" in diameter(i am sure 500mm would be enough length) two rolls of packing and you will need 30 4.8mm rivets, i think aluminium is probably best as they are easier to remove again if need be

i bought all my parts from these guys at a cost of £34 plus postage

http://www.performanceracingparts.co.uk/catalogue/products.asp?cat=3

They are pretty loud as you would expect because you have just built yourself a race can with a 63.5mm core and spout, it is fairly easy to do, but you do have to have a knack for working with tools etc.

Happy coring:thumbup

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