Speedometer Installation

Jim:

I think the purpose of having he tube vertical and above the water line is to allow water to drain out of the tube if some should enter. If you trailer your boat, then the water will drain each time you pull the boat out of the water. If you leave the boat in the water, then I suppose you would eventually lose some of the equalization properties of the tubes volume ( the portion below waterline) and get a bit more movement in the needle. FWIW, my tube is sitting horizontal in the bilge, so I lose about half the effectiveness and do not really notice much needle jump.

Jim, Use a compass to make a 3-7/16" circle where your gage is going to go. Then chuck up a 1/4" bit and drill a hole around the circle (the inner part)every 1/4" or so. Then you can use a jig saw, dremel tool, rotory saw, to "connect the dots". You then have a rough cut hole. Dress it up with a half-round file,sandpaper, sanding drum( on a dremel tool) or whatever to finish her up. The key is to make sure that your drill bit doesn't go out of your circle when drilling. The more holes you drill around the circle the easier it will be to final dress it. It's monotenous and time consuming work but the makes the job easier.

79...:

Keep in mind that Jim lives in Houston, so freezing is not a big issue. Yes, I agree that mounting them horizontally will cause the tubes to suseptible to filling with water...but only half full or half empty if carefully placed to the water can drain back down the line somewhat. I clear my tube of water as part of my winterization process and there is little if any water each year.

Jim:
Another option would be to place the tube vertically behind the instrument cluster. Others may correct me here, but I do not think it matters where the equalization tube is placed along the pressure line.

Sounds like I can mount it anywhere. That increases my comfort factor.

BTW, freezing is definatly an issue here - it got down to 30 one night just a couple of years ago. :)

(I actually live closer to Galveston than Houston, about 15 minutes from the beach, it's a fairly tropical climate, mildew and all. But, if my name was Jim_In_Clear_Lake_TX no one would have any idea where I was.)

Thanks mucho for the input guys. By this Sunday I should know just how slow my waterlogged '68 actually is. I now plan to stick the equalizer anywhere I can find space - I may just hand it to the rider and say: "Here, hold this." (Let 'em earn their beer.)