Hi, all.
Got around to making up some custom intake and exhaust manifolds for the R185. Initial tests with mounting a Solberg 1-1/4 NPT thread air compressor silencer/filter on the stock manifold proved promising that it would reduce intake noise, but something still had to be done with the muffler.
I picked up a 'universal' fit NAPA muffler (fits a '87 Sentra) for about $27. 1-5/8 ID inlet and 1-1/2 ID outlet. 6" dia and about 15" long.
Picked up a chunk of 1-5/8" x .109 wall tubing and 3" wide x .125" strip from the local steel house and made up a intake and exhaust manifold and flanges. It turned out pretty good for a first pass, and I'm a LOUSY welder. Next time I'll have it TIG welded by a buddy. That will save some grinding time....
I found a NAPA paint that matched the ChangFa paint pretty good for the intake pipe and used high temp aluminum paint for the exhaust. Muffler is welded to the exhaust and there's a little brace that I welded from the rim of the muffler bottom to the horizontal portion of the manifold to help absorb the vibration. Air filter is attached to the intake pipe with a piece of 1-1/2" ID radiator hose and two clamps, so it can flex a bit and take the vibration, also, which isn't bad at all.
Anyway, here are the videos:
http://n9zes.zippyvideos.com/gallery.z[edit:] It's not real obvious on the video, but the muffler did make a big difference. The exhaust is just a low frequency PUFF PUFF PUFF sound now. The problem is the mechanical noise of these ChangFa engines is louder than the intake and exhaust put together. Overall, though, it's a big improvement and a worthwhile project!
There are also a few videos (for you diesel heads) of a Detroit powered snowblower at our local airport this past winter. 8V71 running the blower and a 6V53 running the chassis. Sweet sound!
Enjoy!
Chris