Do I need oil temp gages?
 

My entire history of boating has been stock setups. This is the first year that I will be running modified engines. BBC's 500 hp. I did buy new oil coolers that are supposed to be good up to 700hp. They are not thermostatically controlled. I kept the stock oil pans. My builder said that at my hp level they would be fine. I plan on using the 160 degree thermostat for water. I am running the standard belt driven sea pump and brand new BBC standard (marine) circulating pumps. Should I also now start monitoring the oil temps? I see a lot of posts on here that refer to oil temps and how they modify their boating based on those numbers.
My next question is about 02 sensors. I was thinking about running fuel injection so when I ordered my new risers I had them weld in the 02 bungs. I have decided to go with carbs and was going to just plug them up. I was looking through the misc. new posts and pics and noticed that someone running carburetor's also had 02 sensors installed. Do some of you guys also run gages at the dash for AFR? FYI, my new engines have been dyno'd and set up so not sure its necessary to monitor? Looking forward to your comments.

Yes yes and yes.
Extremely cheap insurance.
I`ve never ran a boat without AFR gauges. Dyno AFRs were lways completely diferent than in boat.
Oil temp yes, the more info you have the better.

Agree to all, example of oil being roasted and didn't know
160 degree stat and temps never went above 180 running hard, but oil was getting black fast. Installed oil temp gauge and it was over 330*F. Larger cooler and hoses all good now

Oil temp is one of the most important gauges that should be on your dash.

I replied to your pm about the O2 sensors.

Carburetors… If you’ve got a good tune from your dyno sessions then they’re a nice to have. They allow will help you dial them in just that much more and they’re good for alerting you to trouble (though with a carb you usually get warnings from run-ability first).

Forced induction and basic fuel injection is where these really become important. In these cases you’re using the afrs to spot situations that would contribute to a burn down.

Keep in mind too that this information can be overwhelming and you could start chasing problems that aren’t really there. You should compare your readings with looking at plug condition and so on.

So I'm ordering new gages this week. Where does the oil temp sensor get installed? There is a spot in the oil pan (stock mercruiser pan) that seems a little too high but maybe that what's for? I did see in a different post that had installed his there. I don't know if it was a stock pan or not. Thanks again for your comments. I certainly want my investment to last.

I have Gen VI blocks and take the reading from the oil cooler port right next to the filter pad.

In this application, I'm not sure there's a difference but I am running GEN V blocks. I am still using the stock oil filter relocation mount that locates the filter up by the exhaust risers and it has unused bungs because you can attach the hoses in either direction. Can the sensor be installed there? I believe the goal is to monitor the oil temp at a location that will show how hot the oil gets not how cool you can make it? I did buy the Hardin Marine billet piece to attach to the block itself. Had an issue with the stock unit leaking.

My oil temp sensors are on the remote oil filter housing. Came from Fountain that way I believe. Definitely want oil temp sensors on modified engs.

Water pressure gauge is a good idea too. Saved my bacon once when a water hose popped off.

Thanks for all of the comments and input. I will be loading my dash up with gages before this upcoming season.

I run wide band full time. It's obviously invaluable when tuning but also gives you real time data on how the current motor is running. It can significantly save time when troubleshooting (i.e. do I have a fuel or ignition issue).

When I went from a stock engine to a supercharged build I added gauges to the dash - oil temp, boost, water pressure, fuel pressure, and AFR. Now I find myself monitoring the oil temp gauge the most out of all the gauges on the dash. That gauge alone sparked me to upgrade my oil cooler a couple times to get the size and line size correct.

I am going to order the oil temp gages but need a little help. There's a variety of sending unit sizes so I need a little help with where it goes. I have a spot in the side of the oil pan which I think would be perfect however it's pretty high on the side. I stuck a bent piece of wire in the hole and down 2" and no oil. Oil shows full on the dipstick. I'm assuming that it would get oil splashed on it however that doesn't seem to be the best location for actual data?. Side question, why is there a plug in the side of the oil pan on a factory standard 7.4" Looks like it could be used for a turbo return line?
There's a spot on the block above the oil filter. Is that for pressure only?
I also use the stock filter relocation block still located by the exhaust riser. This would be oil that was already cooled so probably not the info the gage is looking for?
I use an onboard pump attached to the drain plug for changing the engine oil instead of sucking it out the dipstick tube so not sure I could use that location unless there is a fitting that would accommodate both the sensor and the oil change pump.
Thanks for your continued help.
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Put on the filter head, easy
Its before cooler so you will see how hot the oil gets before cooling

Thanks for starting the thread. Been wondering where to add in an oil temp sending unit myself. Filter head looks like a great option that I hadn't considered before.

Agreed on definitely having an oil temp gauge.
I would put it where the oil is hottest (going into cooler).

I have (beside the tach, Speedo, and fuel) the following analog setup:
vacuum gauge to tell me how hard it’s working and if you know how to read them very helpful
oil temp gauge
engine coolant gauge
Volt meter (hooked up so I can see volts before starting and from alternator when running)
Additional sep digital volt meter for house and starter banks.
I also have trouble light and separate lights for bilge pumps that come on when they activate

digital add on
I added a Bluetooth scanner hooked in to my harness that transmits to my tablet to allow custom monitoring in real-time from the ecu (afr, revs, temps, whatever) I can have digital info in real time that way.
In addition I can control my mfd wirelessly on it too.

AllDodge, I'm probably not understanding your location of the sending unit. My understanding of the install of the cooler and lines is that the oil line from the block goes directly into the cooler, out of the cooler to the filter, out of the filter to the engine block correct? Are you talking about the location on the block above the filter as shown in the pic? Thanks for your help.
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Xcomunic8d, So you would use a "T" at the inlet to the cooler that the sending unit attaches to? There is an extra connection point on my new coolers but I thought that was in the path of water. Thanks for your help.

Im assuming that port is a zinc on your cooler? Hard to know without pics

im coming off my remote filter into a T with the sender data in that input hose. Put it wherever is convenient for wire routing. My thoughts mirror the others here what’s the temp before the cooler.

Install a remote filter and install in the filter head
In pic see the brass fitting on the filter head, that is the sensor which goes to the gauge

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Not sure if you have any AN fittings but every AN manufacturer makes these in a variety of sizes

https://www.vaporworx.com/shop/produ...8-npt-on-side/

I used to use one :

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I believe that is exactly what I'm looking for. In my application it goes in the line from the block to the cooler? Thanks for the link.

Anywhere you have flowing oil will be good enough

ICDEDPPL, Just to be clear, this flowing oil should be before the cooler correct? My plan is right off the block to the cooler, to the oil filter, back to the block. I think ALLDODGE has his on the remote oil filter location but for my setup that is going to give me a reading that won't tell me the real temp the oil is getting to. BTW, sorry I said that I thought you seemed like an angry person in a different post :)

You will get varying opinions on where to put the oil temp sensors. I'm in the camp that likes to see what the oil temp is coming out of the engine, pre cooler.

Thanks. That was my thought but wanted to make sure, I have made too many mistakes in the past couple days.

nevermind

ICDEDPPL, I did order my fittings for the temp sending unit. Had to go to a different company as your source didn't have that fitting in -10. Thanks again for the pic and help.

100% agree with above. Also, my understanding about reading plugs is that you need to run the engine medium/hard and then relatively quickly shut it down to read the plug accurately. I am sure I will be corrected if wrong but I understood that even idling to the dock to shut down will influence the plug read.

I think I may have bought 2 items that don't work together. The sensor doesn't really tighten up it just bottoms out in the fitting. Also there's about a 70% blockage when the sensor is installed into the fitting. Is this ok?
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question… based off some of your other threads, are your engines out at your engine builder? If so why not have your builder install this along with the water line you were looking for in another thread? I’m from grand haven as well and would love to know who you are using. I’ve been around for a while and probably know whoever it is. Good luck with everything!

jbraun, My engines are not at the builder's shop. I don't know which post it was but after my meeting with him, I am comfortable with the builds and will be running them "as is". I won't say who the builder is, at least not until there's an outcome from the upcoming season whether it's a great year or huge failure. If I posted his company name now (based on a consensus that there will be a failure) he and his shop would be sent through the "ringer" even though there hasn't been a failure on his part. Just doesn't seem fair to me. I noticed that another member won't post his builder's name either. He had a successful build but is wondering if they did all they said they did. Thanks for your comment.

That fitting is for a gauge not a sensor/sending unit

The sender needs to go into the pan or a port on the remote filter housing. Do not put in an any of the fittings. You will create a blockage trying to do it this way.

Gary, I know I owe you a call! Will try later this weekend.

Here is where I mounted mine on the oil filter housing (Merc.)
Also a pic of my water hose you were asking about.

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Hey Tom, I know my location in the pan is too high and I also thought that locating it in the remote filter housing (at least for me) is after the oil has been cooled so really not the reading I should be looking for?
GLENAMY, if I buy a fitting designed for a sending unit, is it still an obstruction as shown in my pic using the wrong adapter?

You need to plumb oil so hot oil is filtered then go to the cooler. This makes for my location to be correct.
If you are serious, you should throw away the stock filter mount and get a Hardin with minimum 3/4" fittings. The stock ones have about a 3/8" ID opening and an ID of the hose fitting are very restrictive.
Just do it right, forget trying to short cut the proven process.

I'll try this again my last post I can't see.

I drove a 38' Scarab in the late 80's and after just a few minutes of moderately hard running, the oil temps were pegged a 330+. My TR's and 400 Cyclones in my Cobalt 300 Condurre had coolers built into the bell housings, quite large ones in fact. One was for engine oil, the other for transmission using full raw water flow. When I converted to Arneson ASD6's I plumbed both bell-housing coolers to the engine oil, a separate one for the transmission. Gone were high oil temps . . . Plus I added ram water pickups, not those easily clog-able boundary layer pickups on the stern. My sea strainers only ever got busy with the stock pickups, the ram pickups seemed to cut the kelp and leave it in the wake.

I agree with Glen, you need 3/4" or bigger oil cooler lines, a 3/8" will NOT cut it.

I'll check my oil filter block. I assume you are correct and it has the 3/8" fittings. I can order the one from Hardin I suppose. I am trying to do it right. The installation instructions put the line from the engine block directly to the cooler then to the filter and back to the block. Are a lot of guys filtering the oil before the cooler? Other guys are taking their reading from the line to the cooler. I just ordered the wrong fitting and have now ordered a proper in line fitting for a sending unit so I hope that works out.
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