1967 100HP Johnson Water Temp/Pressure Gauge Install

[exodave]

Hi Again Everyone. This is on my V4TL-13.

I've got the motor all torn down for the Winter rebuild. It's been fun discovering all the ins and outs. Here are a few pics.

This last photo is with the water cavity access panel removed after pulling the flywheel. I was happy to see no garbage in there from our adventure running aground last Summer.

This project will be to install a temp sender and I'd also really like to have a pressure gauge for my peace of mind. I am guessing this next pic illustrates a good spot for the sender, using a z-type bracket? It's a small recess just to the right of the top right cylinder head.

Also, not sure where to install the fitting for the pressure gauge hose. Of course, I could just start drilling into the water jacket, but I wonder if I can install it on the thermostat somewhere. Perhaps, tapping into this unused hole which is covered by the thermostat when it is mounted. It seems to be pressurized with water in there when running, since I experienced a leak there when I accidentally got a wire retainer clamped under there once.

In the photo above, it is the hole to the right. When installed, the thermostat plugs it, as shown in the photo below.

Or perhaps it would be more useful to read the pressure inside the thermostat. Any reason not to just tap into the bottom half of it where water from both side of the engine meet?

 

[Bosunsmate]

Re: 1967 100HP Johnson Water Temp/Pressure Gauge Install

Id do it where both sides meet.
Il be interseted to hear what readings you get at cold idle, hot idle and wot

 

[exodave]

Re: 1967 100HP Johnson Water Temp/Pressure Gauge Install

Id do it where both sides meet.
Il be interseted to hear what readings you get at cold idle, hot idle and wot

Thanks, Bosunsmate. If that turns out to be the consensus, I'll snap some photos of the inside of the thermostat early next week so I can try to determine what the best direction to drill into it would be. There is one main void in the bottom half which contains both the vernatherm which controls a valve to the telltale, and another spring valve which dumps back down to the water pump. If I remember right, the area beneath the spring valve is wide open, and might be a good spot to aim for.

 

[racerone]

Re: 1967 100HP Johnson Water Temp/Pressure Gauge Install

Picture #4 is where the pressure gauge fitting would install.-------The factory temperature gauge kit usually installs on the cylinderhead cover.

 

[exodave]

Re: 1967 100HP Johnson Water Temp/Pressure Gauge Install

Picture #4 is where the pressure gauge fitting would install.-------The factory temperature gauge kit usually installs on the cylinderhead cover.

It appears to be just a recess, not a removable plug. Would I need to drill and tap in there for the pressure fitting?