Auxiliary gauge mounts

There is also a picture showing my extra instruments for monitoring oil pressure and volts. Both are 52 mm instruments, placed in car exhaust pipe parts and clamped to the steering bar. Rather cheap and secure way of fitting those instruments, the problem is of course to make them watertight, but that could also be solved by choosing marine instruments :)

When I was doing the resto on my bike I was still employed as a Senior Technician at an R&D Lab, working on Advanced Materials. As such I had access to all sorts of material stock. The mounts for the gages are made from two 3 inch long sections cut from a section of aluminum pipe I found on one of the stock racks. It's dimensions are: OD 2.63 inch wall thickness about 0.15 inch. Whether it's a standard size, Where it came from I have no idea. The labs were originally set up in the early 60's by the Babcock & Wilcox Company for their Nuclear development. The length of pipe had some age on it when I used it in the mid 90's, so it may well have been a drop from some reactor component.

UPDATE: After writing the above I got curious & started looking through my collection of sources Aircraft Spruce & Specialty Company sell round aluminum tubing 6061T6 in 2 ¹⁄₄ inch and 2 ¹⁄₂ inch ODs with 7 different IDs & wall thicknesses. It's sold by the foot. I've never dealt with this company, but I got the catalog from friend Clifford who has had good experience with them.

I polished the pipe sections and epoxied them to the front cutouts in my Police dash. I didn't want to drill holes in the dash casting in case the gages didn't work out & I wanted to go back to stock. The epoxy I used was a super-zoot Meta-Set A4 by Smooth On we had at the lab. (these days I use J-B WELD, it looks, acts, & smells like exactly the same stuff).I wrapped the gage bodies with beer-can aluminum & aluminum tape so they are a snug fit in the pipe. I made a plate to bolt up to the two all-thread studs on the back of the gages, drilled holes in the plate, & cut 4 lengths of fine all-thread long enough to protrude from the bottom of the pipe sections when bolted into the holes. I cut two plates to go across the bottom of the pipe sections w/holes for the all-thread. Using nuts on both sides of the plates w/ a drop of thread locking compound has yielded a set-up that has been pretty much trouble free for about 13 years now. I have always run a fairing, so the bottom of the pipe sections are hidden & don't have to be pretty.

The gage needles do dance from the bikes' vibes, & I've had to replace each gage once due to failure over the years/miles. The oil pressure gage is mechanical. I cut, drilled, tapped, threaded & silver soldered a T fixture that screws into the block & supplies a feed to the gage an allows me to keep the idiot light sender. The pressure line to the gage is plastic/teflon?, It has failed at the connection to the T hose connection. Oil shot out from under the tank & made quite a mess. I ran the replacement pressure hose inside some tygon tubing to help damp vibration, & I carry an extra tube fitting with the hose melted closed to put on the T for emergency repair if it ever happens again. I've got a set of high-bux VDO gages on the bench to install the next time I have the fairing off, I'm hoping they'll be more stable than the el-cheap-o Sunpros I've been using. The hot set-up would be gages filled with liquid silicon for vibration damping, but I've never found a silicon filled 2 inch gauge, it's only used in the larger sizes. Readings? w/about 45K on the motor rebuild, the oil pressure readings I get are: 60 PSI cold, 50 hot above 1000 RPM & 20 cold 15 hot at idle. I'm running the awesome Greg Field alternator & get a 14 volt reading as soon as the RPMs come off idle. If you zoom in on the picture & are curious about the black box between the gages on the front of the dash housing it is a turn signal beeper.