How to chop / cut down an EVO Sportser cam cover

[RickG61]

OK, be gentle here, it's my first HOW TO thread.

I'm working on an 86 1100 Sporty, doing a hardtail kit install, springer front, etc, and wanted to cut down the size of the cam cover during the build. I searched the forums here, noticed a bunch of, "how do I do it?" questions, but never came across an actual, "here's HOW to do it" thread. If I missed it, and the other one or more are mo better, feel free to ignore this one. LOL

OK, after consulting the often suggested shop manual, I dove in. Mine has an ignition module hidden behind a generic chrome points cover. Removing a few small screws, after I took a bunch of pics, and twisting cussing etc, the module popped out. Mine uses some factory bastard molded 3 pin plug that's obsolete, and the pins wouldn't release release from the rubber, so, a pair of diagonal cutters and three snips later, I pulled the connectorless wire through the housing and out of the way. I cut the rubber vent line at the rear of the cover, and disconnected the breather line at the front of the cover, from the back of the air breather, but temporarily left that hose in place. No reason, just did it that way. OK, cover is now separated from engine, and ready for cutting.

My first thought was to flip the cover over and using an 1/8" drill, drill a series of holes along the bottom of the bulkhead that runs up to the gasket surface, then flip the cover over and connect the dots with a cutoff wheel. That would keep me away from that bulkhead and gasket surface and give me a "pattern" to follow, which could then be cleaned up with sanding/filing/grinding. In the end, I decided that the crappy mix of rattle can paint the previous owner sprayed on EVERYTHING, plus what was left of the factory crinkle finish, could be used to scribe a line to follow. So, using dividers, set to the thickness of the cover material, I ran one side of the divider along the inner bulkhead wall, while squeezing the dividers tight to the cover, which scribed a cut line in the paint on the exterior side that mimicked the contours and bumps on the wall underneath of it. This gave me a pretty good, easy to see, even with my old tired eyes, line that I then used a cut off wheel to follow. I didn't want to follow all the bumps around the bolts, but rather make a straight cut that avoided those bumps. This scribed line showed me where those bumps were, and allowed me to follow a line below the scribe, straight, that would miss them.I started the cut using a body say, but that was going real slow. so I switched it up to the cut off tool. In the photos I have two colors of tape applied to the exterior of the cover that follow the scribed line in the paint, again, straight, instead of around the bumps. This would give me an easy to see line, plus the benefit of protecting the surface slightly if my wheel strayed when starting the cut. This turned out to be a pain in the ass, and I removed the tape, held my tongue right, and just followed the scribed line in the paint. Actually, I made sure to stay slightly below that scribed line so it would allow me room to sand to where I wanted to be, instead of chancing hitting the wall underneath and creating a divot that I couldn't get rid of without welding up and sanding down. Of course, it would have only been visible to anyone if I was running over their head at the time. LOL But I didn't want to deal with it anyway. While cutting, I laid the cover on a scrap of wood to protect the gasket surface, and I purposely left as much of the old gasket stuck to it for the same reason. Hard enough to get a good seal on that thin cross section, didn't want to scar it up too.

My first cut was the long cut along the bottom of the cover. A fresh, full diameter cutting wheel is long enough to cut through the thicker parts hidden behind and at the bends of the cover. If your using a 4" grinder with a cutoff wheel, it would probably go quicker, but you'd have to raise the cover up or clamp it to the edge of a bench so that the wheel had clearance under the cover without getting into whatever the cover was setting on.

After making the long bottom cut, and staying just over a 1/4" away from the bulkhead on the backside, I again grabbed the set of dividers and scribed at the rear portion of the cover. I've seen covers that were cut pretty much straight down, but I opted to keep the boss on the back rear portion that slips over the locating pin. There is a slight amount of slop around the bolts/holes, that could allow the cover to be shifted slightly when installed, and I didn't want to take a chance and have the cam bearings misaligned with the bearings on the engine side of the cams. This pin will keep the cover from moving out of alignment. Keeping the boss at the bottom rear meant that I had to make a series of smaller bisecting cuts to eat away the material at the rear of the cover. I left myself another 1/4" of clearance away fro the actual sealing surface when making the cuts, so I could sneak up on the finished surface after the initial cut.

Once the cuts were all made, I took the cover over to a cheapo Harbor Freight 12" sanding wheel I have to clean up the long lower edge, and start the initial rounding of the material around the boss at the rear. This diameter of wheel made it easy to clean up the lower portion in a nice straight line along the bottom. I opted to leave a small lip at the bottom for two reasons. It would keep the edge away from the bolt holes, and the lip would be hidden, unless, again, your head is laying under the bike. It also left me a little of the boss that's cast in underneath the bearings, that acts like a dirt/sludge trap from the bearing area. The factory hammers a small plug into the bottom of the cover to seal it. Leaving the boss thicker will allow me to thread it so I can screw a small plug into the hole.

The rear portion of the cover was initially rounded around the boss using the disk sander, then I used the belt/disk sander I have. Its just a small 1" wide belt that was perfect for getting in and around the boss at the lower rear, and made the final rounding easy, as well as cleaning up the short straight cuts running more vertical at the rear of the cover.

I finished it all up using some surface prep Roloc wheels on the small angle grinder. I used a brown coarse wheel to remove some area around the locating pin, but caution, that wheel cuts FAST and you don't want to use it when creeping up on a line. For the finer finishing blending, I switched over to a purple wheel. I put a slight rounding over on the front edges of the new cut lines, as well as blending the pin boss area at the rear.

After the cuts and sanding, I used the purple wheels to remove some of the black paint and to massage a few scratched and scars that were on the cover and hidden under grease and paint. Total time invested was about 30 to 45 minutes from start to finish.

My plans are to have this cover, and a few other pieces powdered. If you're NOT doing that, be warned, there's going to be grinding/filing/sanding dust everywhere, so you'll need to protect the bearings. Then, after countless hours of taping and protecting, plan on spending some quality time with a parts washer to flush them out anyway. LOL Since mine will get blasted before the powder goes on, and I'll be doing a bunch of cleaning afterwards, I didn't spend a whole lot of time on clean up after this cutting, since I'll be doing it all again.

Pics to follow.

[RickG61]

Here's kinda the starting point. This shows my ill fated tape line that I end up removing

[RickG61]

Here's a few shots of how the line was scribed. You'll have to use your imagination a bit, since I had already applied the tape when I decided to take pics. This gives you an idea of how the dividers run along the inside wall, following the bumps in that wall, and how it will transfer the line to the front surface where you'll be doing the actual cutting from. Again, you could accomplish a similar result by starting on the rear side, and drill small holes below that same wall, through the cover to the front side, then connect the dots.

[RickG61]

OK, here's my tools of mass destruction, a cut off wheel and a body saw, as well as a shot of the initial cut along the bottome edge of the cover. I tried to keep this nice and straight, leaving the option of sanding/grinding to the wall on the backside, and having every bump and contour transfer to the front. I decided after this cut, I liked the idea of a straight bottom that did not intersect any of those lower bolt holes. You'll see later, on the rear portion, how one or two of the cuts DID intersect the bolt holes. This was on purpose, since I wanted to see the contours of the inner wall, that would be visible if you were looking down at the cover.

[RickG61]

OK, here's the initial cuts made along the rear portion of the cover. Its a series of smaller cuts, no long straight line, since I wanted to preserve the boss on the lower rear portion of the cover that accepts the locating pin.

[RickG61]

This is the 12" disk sander, and a small 1" belt sander I used to shape and smooth the cut lines. You could also do the same with files, sandpaper, small hand sander or 4" grinder with flap disks. The disk sander is a cheapo Harbor Freight that with a coupon, I paid like $80.00 for, and I've used the hell out of this thing. Well worth the money, and surprising, for Harbor Freight, its been real durable.

I used it to sand a nice straight bottom line, as well as to start the initial rounding around the boss at the lower rear portion of the cover. Then I switched over to the small belt sander to get into those short straight sections at the rear above the boss.

[RickG61]

Here's after the first pass through of the disk and belt sander. The shape is close to what I want, bottom is nice and straight and boss is rounded over, as well as the top rear portion starting to blend in nicely with the top lines of the cover

[RickG61]

Using the small angle grinder and a brown Roloc wheel for quick removal, then a purple Roloc wheel for final blending and smoothing, I've dressed up the boss on the back side of the cover. This COULD be seen when assembled, so I wanted it smoother than the big ugly lumpy boss as cast. Of course, the chain will hide a lot of this, but, it took all of 5 minutes with the Roloc wheels, so what the hell, why not.

[RickG61]

Here's a view from the lower portion of the cover. This is the wall that the scribe was following when scribing the front visible portion of the cover. You can see there are a couple of bosses there. The more squared one to the right runs all the way down the back portion of the cover and is plugged at the factory with a small pressed in plug. There's an internal passage that leads up to a bearing. It will see lots of oil, so you'll have to plug it after cutting the lower portion of the cover off. I'm going to tap this and install a screwed plug into it. I've seen some cut covers that followed all of those bosses instead of keeping it straight at the bottom. I decided I'd keep it straight, and avoid the bolt holes on the front of the cover. It leaves a small lip that will not be visible from the front, gives a nice clean straight line at the bottom.

[RickG61]

At this point, the lines are all where I want them. The blending and contouring are done. I used a used purple Roloc disk to remove some of the black paint from the front, and polish out a few divots the previous owner installed. LOL I then removed that damned hose that I fought the hole time. Take my advice, get it out of the way before you start. LOL

Its now ready to be delivered to the powder guy, along with the rocker box covers, primary cover, inner and outer rocker covers and spacer. I'm going gloss black on all of it, with the exception of the spacers. Bright red for those. I may throw the pushrod tubes in there as well, since the previous owner did a half assed job of scuffing the chrome and rattle canning some black on them.

Thanks for reading along. Hope it helps.

[RickG61]

Stack of most of the parts heading for powder. I'm going to use some solvent to remove the old crinkle paint and rattle can flat black the previous owner sprayed on the rest of the engine, and decide if I want to recrinkle it, or ??? Kinda torn at this point between raw aluminum look, plain smooth semigloss black, or the crinkle blank with a very small amount of shiney hardware. Not a huge chrome fan, so whatever is used, will be sparingly.

The bike at the bottom was the starting point. I think the previous owner MAYBE removed the seat, then sprayed everything else with rattle can black. A lot of that flaked off, or could be removed with a fingernail. I picked this thing up at a Sheriffs auction. That rattle can guy kinda got busted selling controlled subs. This could have been the new DARE bike. LOL They labeled it as an "Administrative forfeiture". Kickstand spring was broken off, but its got less than 24,000 on the odometer and runs great.

[wot2t]

i want to see it all done, on the bike.....

[Steelsmith]

Not to be rude or disrespectful of your efforts, I simply don't know/don't have a Sportster. Why would you make this modification/what is it's purpose/benefit to you or the bike?
I have been looking/reading about Buell versions of the Sportster, so I have a legitimate reason for asking about Sportster mods.

[farmall]

The mod was originally a way to reduce excess weight for racing. The removed metal is decorative so nothing of value is lost. On the street it's for style, the purpose of chopping.

It's also (slightly) easier for maintenance access to wires/hoses which would run beneath the decorative cast fairing.

[Steelsmith]

Thank you for the answer Farmall!
So this truly follows the original intent of chopping, if it doesn't help you go faster and it isn't nessessary for operations, it goes!
Thanks for revealing this bit of detail, I'll be looking for it and other examples of weight-savings and improved access mods, in the future.