The original exhaust on my '67 CL is in great shape, with the exception that a previous owner sawed the end off the muffler and yanked out the baffles. Needless to say, it was loud. I found a set of pipes off a '66 that were decent and the price was right so I got those with the intention of putting either a '66 repro muffler on them or maybe a set of the EMGO 12 inch shorties that look like the old Bate's Shorties.
The guy I bought the pipes from had a restored '66 and he used an old trick from when the bikes were new. He put a pair of old VW chrome exhaust tips from the original Beetle in his pipes. They are a perfect fit and just need a screw on the back side to hold them in place. So I thought I'd go that route because it's a nice clean look. But when I went to buy the exhaust tips (which you could buy in K-mart in the early 70's) I could only find them on-line and locally in two auto parts houses, NAPA and BAP-GEON. Both stores carried the same tips, which are made in Brazil and are garbage. Plus they are now between $14 and $17 each, so not a cheap alternative. I looked for NOS on ebay and found a set, but they were from different engine sizes meaning the ID was different on each one.
One the way back from BAP-GEON I decided to make my own baffles. I had the design done in my head by the time I got to the Metal Supermarket, which was right down the road. I bought a 4 inch chunk of 1-1/2" Aluminum barstock for $5 and headed for home.
Attached is the final product. The baffle is a piece of 7/8" OD steel thin wall tubing I had in my stock, which was the handle for an old Toro electric snoblower I had thrown out. It's actuall chrome plated. I've used that handle tubing for a bunch of projects and this is yet another. The end cap is a simple 3/4" copper tubing end cap. 99 cents each. It is held in place with a self-tapping sheet metal screw.
The tubing was drilled with a 1/4 " bit at 1/2 inch intervals. there are 36 holes total. The exposed portion of the tubing is 5 inches long. I was not sure what the total area for the sum of the holes should be. So I figured the sum of their area should be at least the area of the ID of the exhaust pipe. For 1/4" holes, that came out to 31 holes. So, with 36, I figured I was okay.
My pipes had snuf-r-nots in them at one time (I hate snuf-r-nots) which means there already were enlarged holes in the ends of those pipe. I thought about using those at first, but they were ugly and no longer round. Plus the one on the bottom pipe was less than 1/8" from the edge. So, I made up a brass form for the inside of the pipes and MIG welded up the holes and then finished off the welds flat. Chrome is not so hot on these pipes so I had nothing to lose.
I drilled new screw holes to keep the baffles in place on the back side of each pipe, 1/2 inch from the end and tapped the end caps to accept a stainless 6mm pan/socket head screw. This screw holds both the the perf tube to the alum end cap as well as the entire assembly to the pipe.
Temps were nice so I figured, lets see what she sounds like with these in place. Plus, it was time to blow the cobwebs out of the engine after sitting all winter.
It sounds great. Maybe just a little louder than a stock Honda, but nothing like that gutted muffler sounded. Took the bike for a spin and did a plug chop on the way back and coasted into the driveway. Both plugs looked perfect with a nice tan color and a dash of carbon around end of the threaded portion. I had replaced the 160 mains that came in the bike when I got it last year with NOS 165 mains. Looks like my baffles emulate the same back pressure as the original muffler.
We'll see how they hold up. Might find that I need to get some stainless 7/8" tubing to replace my snoblower handle if it corrodes away quickly. But this engine smokes just a tad so maybe that's enough oil to keep it from rusting.
Total cost $7.00 and I think it looks better than the other two options.
Guess I'm going to have to get those pipe rechromed now, unless I can find a better set.
regards,
Rob
Home made baffles and end caps for my CL77 ExhaustHome made baffles and end caps for my CL77 Exhaust
Rob
That's a very clever and beautiful piece of work. With the materials you have used they will outlast the originals and will be much easier to extract for cleaning etc. I used a similar technique with just an aluminum end cap to quieten some stainless 'mufflers' I bought for my Guzzi, but they don't look half as nice as yours! Well done and thanks for sharing. G '60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160 '66 Matchless 350 '67 CL77 '67 S90 '77 CB400F
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