Has anyone installed a cylinder head temp gauge?

[Saskatoon2005]

Hello all,

I was just curious if anyone has installed a cylinder head temperature gauge? You know the one with a "Z" bracket bolted to the cylinder head, and then having the sensor screwed into the "Z" bracket.

Also has anyone done this on a late 50's or early 60's johnson Outboard? I have a 40 HP outboard and would like to install one. Just wondering how helpful they are.

I have also heard you should install a water pressure gauge with this as well. How would someone install a water pressure gauge in an old 1961 Johnson Outboard. A 40 HP model RDS-22.

 

[samo_ott]

Re: Has anyone installed a cylinder head temp gauge?

RDS-22 is a 1960 model according to my book as I have the RDSL-23 (long shaft 1961 model). I have never seen a water pressure gauge on one though, not sure where one would install it. You might have to drill and tap and the pressure is probably quite low...

 

[ezeke]

Re: Has anyone installed a cylinder head temp gauge?

The Z-bracket is easy to install. The BRP/OMC kits come with everything you need as will the Teleflex kits they sell here at iboats.

The best thing about having either or both of the gauges is that it gives you some advance warning when things are not working normally. The longer you use them the more aware you are of the slightest change in the readings.

I installed the temperature gauges on my 1970's V4 motors many years ago. They still work fine and I have never had problems with them.

The water pressure gauge is strictly mechanical, but the temperature guage will need a 12 volt source.

The teleflex site has good instructional and trouble shooting pdf downloads if you want to study the gauges a little more before you decide.

"http://www.teleflexmarine.com/cgi-bin/frameset2.cgi?site=gauges&type=us&link2=1047"

Just copy the link to your browser without the quotation marks. Scroll down the page when you are on the Teleflex site.

 

[F_R]

Re: Has anyone installed a cylinder head temp gauge?

I've installed lots of the temp guages. They work OK. Try to put the Z bracket under one of the warmest head bolts, that is one high up on the exhaust side of the block.

 

[Saskatoon2005]

Re: Has anyone installed a cylinder head temp gauge?

So does that mean there is no chance of getting a Water Pressure Gauge on this outboard?

I did mean RDS-23. I was told, that it was better to have BOTH gauges for best protection, but I guess 1 is better than 0...LOL!

So where is the exhaust side on the cylinder head for a 1961 Johnson 40 HP outboard? I would like it to be somewhere hot, so I can moniter it as best I can.

Thanks everyone for your replies. They have been a great help!

 

[F_R]

Re: Has anyone installed a cylinder head temp gauge?

There is a large cover on one side of the engine block, and two smaller ones on the other side. The large one is the exhaust cover.

I've never attempted to install a water pressure gage on one of those. I wonder if it would even be effective, given the fact that the thermostat is constantly opening and closing. There is always water flowing whether open or closed, but does the pressure fluctuate? I dunno the answer to that one.

 

[samo_ott]

Re: Has anyone installed a cylinder head temp gauge?

Here's photo's of my RDSL23. The exhaust cover is on the starboard side.

"www.ovhi.ca/johnson40/johnson40_2.JPG"
"www.ovhi.ca/johnson40/johnson40_3.JPG"

 

[samo_ott]

Re: Has anyone installed a cylinder head temp gauge?

And F-R, think of an auto. The thermostat is always opening and closing... and the water is always flowing... Is there a diff? I dunno either.

 

[Silvertip]

Re: Has anyone installed a cylinder head temp gauge?

You will always have pressure whether the thermostat is open or closed. If you didn't, the engine would overheat. The pump supplies more water than can be passed through the engine so therefore there will be positive pressure in the cooling system. Drill and tap a hole for a brass barbed fitting on which you will attach the pressure hose that leads to the gauge. Unless you install a new water pump impeller at the same time you will not know what "normal" water pressure is. Note the low and high readings and in the future any deviation from those readings are a sign that the impeller needs replacing.

 

[Saskatoon2005]

Re: Has anyone installed a cylinder head temp gauge?

Hey Silvertip,

Where do I drill and tap a hole for a brass barbed fitting? I know where the thermostat housing is. Do I tap into that? Where on there? before the thermostat, or after? I would surely love to have a pic to show me exactly where to install it.

 

[F_R]

Re: Has anyone installed a cylinder head temp gauge?

Does your automatic choke still work? If not, the elbow where the hose comes off the block to go to the choke would be a wonderful spot. I think. At least it sure is available. However, because of where it goes from there I doubt that a tee in that position in order to retain use of the choke would be satisfactory. One way to find out - try it.

 

[Saskatoon2005]

Re: Has anyone installed a cylinder head temp gauge?

My automatic choke does not work anymore. I may have to try that, unless Silvertip (or anyone else) suggest otherwise. Yeah, it would be awesome to not have to drill and tap anything if I don't have to. I could just hopefully screw into where the elbow would go and let it continue onward to the useless choke. Makes me curious, thanks for the input F_R.

Patrick

 

[Willyclay]

Re: Has anyone installed a cylinder head temp gauge?

As others have stated, a water temperature gauge is a very nice addition. I installed the OMC version on my 1962 Johnson 75hp V-4 as a means of checking the OE overheat light that came on every time I used full throttle for more than 30 seconds. It was a bad sensor!

I also had a 1959 Johnson 35hp that was basically the same motor as your 40 and it gave many years of bullet-proof service. If you are going to all the trouble of tapping into a water line, why not just add a pee-hole that you can monitor instead of a gauge?

 

[Saskatoon2005]

Re: Has anyone installed a cylinder head temp gauge?

Willyclay,

Have you ever installed the water pressure gauge in your 1959 35 HP? I have a pee-hole, but it just sprays water and not pees. Where would I add a pee hole if i was going to go that route? I would still be tapping into some water jacket....might as well monitor water pressure while I am at it...LOL!

 

[Silvertip]

Re: Has anyone installed a cylinder head temp gauge?

I'm not familiar enough with your engine to tell you where to connect a pressure gauge. They are typically "teed" into the tell tale as shown here on my Merc. Anywhere that opens into the cooling system will work. As I mentioned, the pump supplies far more water than can pass through the engine so it really doesn't matter much where you tap in. You want to be at the highest point on the cooling system as this allows any trapped air to escape which was a problem on some older OMC triples.

 

[Willyclay]

Re: Has anyone installed a cylinder head temp gauge?

Sorry, I never installed a water pressure gauge on any motor. I'm old school and like to see the pee-hole. FR suggested you tap into the automatic choke water line but I don't believe you addressed that possibility. I certainly do not recommend tapping into the exhaust water jacket. You need to find an existing line or plug to get the water flow needed for a gauge and/or pee-hole. Also, I think we are talking about a TWO cylinder motor.

 

[Silvertip]

Re: Has anyone installed a cylinder head temp gauge?

Willy -- The tell tale in the above picture is indeed installed in the exhaust water jacket cover and is where the factory placed the tell-tale. The small line is the pressure gauge and bigger one the tell-tale. There is only water in that area, the exhaust is behind another plate (the actual exhaust cover) between the water cover and the block. It is a very logical place to install the gauge and there would be no difference in pressure at that point that in a port in the cylinder head. Old school is fine, but your eyes cannot detect small water pressure changes over time. Just because there is a stream of water, does not mean the pump is at full capacity. In fact it may be on its way to failure. Impeller disintegration sends bits of rubber into the cooling system where it gets lodged and creates other more serious problems. A pressure gauge lets you know immediately if the pump is working properly. As I said, I'm not familiar with the water line to the choke on that engine. It's certainly simple enough to try it and see. It certainly is not going to hurt anything.

 

[DHPMARINE]

Re: Has anyone installed a cylinder head temp gauge?

Tell-tale and /or pressure guage only helps if you watch them.I think the pressure guage is better,because if you normally read 20 psi,and now it's down to 12,you know there is something wrong.A tell-tale does the same thing,but unless it quits,how much stream is how much lesser than last week ?

DHP

 

[Saskatoon2005]

Re: Has anyone installed a cylinder head temp gauge?

FR suggested you tap into the automatic choke water line but I don't believe you addressed that possibility. I certainly do not recommend tapping into the exhaust water jacket. You need to find an existing line or plug to get the water flow needed for a gauge and/or pee-hole. Also, I think we are talking about a TWO cylinder motor.

 

[Saskatoon2005]

Re: Has anyone installed a cylinder head temp gauge?

I did address that possibility,and am thinking that is a very good idea.