No heat in the motor

[Husqy510]

Some of you may have followed our build on boat restorations, but for those that haven't, we just finished building a 26-foot Howard that had never seen the water.

A couple days ago we ran it for the first time and it runs great, but doesn't build any water temp. The oil temp got just above 200 after a few half throttle passes at 4500rpms, but water stays around 110. We have a two stage water pump with 1 port cooling the motor, exiting through the exhaust, and the other plumbed to the oil cooler and exiting out the side of the boat.

Two questions. Is it an issue that the water doesn't develop any heat? And what's a reasonable oil temperature?

 

[Husqy510]

Here's a quick clip of it running. Naturally aspirated 540 making a little over 700 horsepower.

 

[28Eliminator]

Thermostat?


Sent from my iPhone using Tapatalk

 

[Husqy510]

No thermostat. We did a lot of research while building this boat and most of the motors built by reputable builders did not have thermostats

 

[mattyc]

Was the motor machined and assembled with additional clearance to allow for cold water operation? You wont see much temperature in the water when not using a thermostat, but that doesnt mean the internals arent hot. I have been told 230-240ish is ideal for oil temperature.

 

[Husqy510]

Thanks for the reply. Yes the motor was built for a marine application with appropriate tolerances.

We didn't run it very long, or very hard, but I believe the oil temp will probably be right where it needs to be. For now we're going to change all the fluids and we'll take it out and run it a little harder and longer

 

[CSmith]

We have pretty similar setups. Ours is a 540 N.A and dynod at 750 HP. At first we were running a t stat but were still getting warmer temps than I was comfortable with (220-230) so we had tried drilling a couple holes in the thermostat so it would still allow some water to flow through even when closed and that brought temps down quite a bit, but after talking to a few reputable shops here in Havasu they also told us to just take it out and make the system simple. Now we have been running ours with no thermostat and just the crossover and our temps are roughly 110. We have roughly 100 hours on the motor now and runs great.

 

[vdcruiser]

If you run the water through the exhaust first it will pre heat it and the engine will run hotter.

 

[Maestro]

I'd have to double check but I believe mine is plumbed as followed
Pump to oil cooler, to motor, then exhaust.
I have lightning headers so I can't pre heat the water via exhaust

 

[vdcruiser]

I know what you mean, I had Lightnings like that one time. He makes them so you can preheat the water, but you would have to get a new set.

 

[Husqy510]

Thanks for all the good info.

We got a great deal on an accessory drive set-up which included the two stage water pump. Our Lightning headers don't allow us to preheat water, so one pump goes through the motor and out the exhaust. The other pump goes through the large cooler and out the side of the boat. I've included a pic

A lot of the reading I've been doing supports keeping the motor as cool as possible, as long as the oil warms up above 210. The theory is keeping the cylinder heads as cool as possible helps prevent detonation and keeps the exhaust valves cool. The only other issue is it makes it a little tougher to get a good consistent idle.

 

[oldschool]

Thanks for all the good info.

We got a great deal on an accessory drive set-up which included the two stage water pump. Our Lightning headers don't allow us to preheat water, so one pump goes through the motor and out the exhaust. The other pump goes through the large cooler and out the side of the boat. I've included a pic

A lot of the reading I've been doing supports keeping the motor as cool as possible, as long as the oil warms up above 210. The theory is keeping the cylinder heads as cool as possible helps prevent detonation and keeps the exhaust valves cool. The only other issue is it makes it a little tougher to get a good consistent idle.

Yes. Just make sure you build some temp in the oil before running the boat very hard. Cold water and warm oil are fine. My 565 twin turbo will run about 100 degrees water temp and 220 oil most of the time, on longer harder runs water temp will come up to about 150ish and oil temp will bump up to about 240 ish. This is in a vdrive, no thermostat and a big Olson oil cooler.

 

[Dalton]

i think ive seen oil filter heating elements

 

[Riverbottom]

I have always run Mercruiser thermostats in my v-drive cruisers. The 142* thermostat keeps the motor at a nice constant temp.

 

[obnoxious001]

Ian,, here are my thoughts. Go ahead and do your next testing, see if your temperature climbs, but also remember, you are measuring water temperature. This time of year the water entered the engine at what, 60 degrees or so, depending on where you are? So it's picked up 50 degrees by cooling the metal parts. I suspect that the actual temperature of the parts is higher than 110 degrees, don't you?

Having assembled many turbo race engines at GT Performance in the past, have to agree with oldschool on this. My own engine ran cool, but during the summer, I did see it reach 190 degrees at a race at Lake Mead, air temp probably around 120, pulling my Aussie friend Daniel Cotton in a men's open ski race.

I would not worry about seeing the low water temp.

 

[yankcan0]

I also had a concern about my engine running too cold. After my last rebuild, switching to a roller cam which creates less heat, I installed a Moroso restrictor washer in the thermostat housing. Never ran a thermostat since sand suspended in the raw water can screw those up. It still runs cool but not as cold as it used to. Moroso sells a pack with three different restrictor rings. I used the middle size, figuring if it got too hot I could go to the other less restrictive ring. Seems to work for me on my .030 over 454 v-drive Spectra 24xs daycruiser.

 

[DaveH]

first you need to verify your gauge is accurate before assuming its running ice cold. ive seen autometer gauges wayyyyyy off.

 

[Streetmoto]

first you need to verify your gauge is accurate before assuming its running ice cold. ive seen autometer gauges wayyyyyy off.

That was the first thing we checked since I've had issues with temp gauges as well and the block/heads felt to be about the same temp as the gauge was displaying. And like Barry mentioned, the water at the river is really cold right now, guessing we'll see something different when the temp is 70+ and we run it for longer than 10 minutes at a time.

 

[Husqy510]

Ran the boat a little more today and we're still not getting any heat in the motor, but the oil warmed up quickly. After a short blast up to 90mph and about 5500rpm the oil got up to almost 260. The motor still wasn't registering heat, and the water discharge for the oil cooler was cold.

Do we need to restrict the water discharge for the oil cooler?

 

[Husqy510]

The oil cooler was hot to the touch

 

[28Eliminator]

Ran the boat a little more today and we're still not getting any heat in the motor, but the oil warmed up quickly. After a short blast up to 90mph and about 5500rpm the oil got up to almost 260. The motor still wasn't registering heat, and the water discharge for the oil cooler was cold.

Do we need to restrict the water discharge for the oil cooler?

Is the direction of the oil flow (through the oil cooler) going AGAINST the direction of the water flow?

 

[oldschool]

Ran the boat a little more today and we're still not getting any heat in the motor, but the oil warmed up quickly. After a short blast up to 90mph and about 5500rpm the oil got up to almost 260. The motor still wasn't registering heat, and the water discharge for the oil cooler was cold.

Do we need to restrict the water discharge for the oil cooler?

Sounds good to me, but I would verify that the water temp gauge is working. Don't restrict the water flow on the oil cooler, it will build pressure and could leak.

 

[Husqy510]

currently water and oil are traveling the same direction. We'll try switching directions

 

[DaveH]

That was the first thing we checked since I've had issues with temp gauges as well and the block/heads felt to be about the same temp as the gauge was displaying. And like Barry mentioned, the water at the river is really cold right now, guessing we'll see something different when the temp is 70+ and we run it for longer than 10 minutes at a time.

how exactly did you confirm they are reading correctly?

one common issue is single wire sensor MUST have the body of the sensor grounded to the engine block. teflon tape, remotle sensors on lines or coolers......may not actrually be grounded.

you check this by reading resistance from the body of the sensor to ground. should be ZERO.

 

[Husqy510]

how exactly did you confirm they are reading correctly?

one common issue is single wire sensor MUST have the body of the sensor grounded to the engine block. teflon tape, remotle sensors on lines or coolers......may not actrually be grounded.

you check this by reading resistance from the body of the sensor to ground. should be ZERO.

We'll be sure to check that, but the guage does seem to respond appropriately, meaning it showed about 190 while cruising and went up as we pushed the motor. The oil cooler was pretty hot as well.

 

[ToMorrow44]

how exactly did you confirm they are reading correctly?

one common issue is single wire sensor MUST have the body of the sensor grounded to the engine block. teflon tape, remotle sensors on lines or coolers......may not actrually be grounded.

you check this by reading resistance from the body of the sensor to ground. should be ZERO.

Another way to check is to ground the body of the senor (the hex where you put the wrench) to the terminal. It should make the temp gauge go all the way to the right.

 

[DaveH]

Another way to check is to ground the body of the senor (the hex where you put the wrench) to the terminal. It should make the temp gauge go all the way to the right.

true...and if it doesnt....that proves either the senor body isnt grounded, OR the wire from the senor to the gauge is bad OR the gauge itself is bad OR the sensor is bad.

 

[Husqy510]

I'm heading to the river Tuesday and plan on checking.

 

[TexasJet]

Water flows thru the tubes. Oil flows around the tubes.

 

[Streetmoto]

Ian,, here are my thoughts. Go ahead and do your next testing, see if your temperature climbs, but also remember, you are measuring water temperature. This time of year the water entered the engine at what, 60 degrees or so, depending on where you are? So it's picked up 50 degrees by cooling the metal parts. I suspect that the actual temperature of the parts is higher than 110 degrees, don't you?

Having assembled many turbo race engines at GT Performance in the past, have to agree with oldschool on this. My own engine ran cool, but during the summer, I did see it reach 190 degrees at a race at Lake Mead, air temp probably around 120, pulling my Aussie friend Daniel Cotton in a men's open ski race.

I would not worry about seeing the low water temp.

Barry, we're still having issues with the oil temp getting hot. Ian was out yesterday and just under cruising load the oil got up to 240 fairly quickly. One of the two water pumps off the accessory drive is dedicated to the oil cooler and then dumps out the side of the boat. Is there a chance the water is flowing through the cooler too quickly causing cavitation and decreasing the contact surface area (making it less efficient)? We have one more unused dump out the side of the boat, my thought was to put a Y before the water inlet of the oil cooler to divert some of the water out the side of the boat slowing down what goes through the oil cooler. I'd put a ball valve on that line to dial in the amount of water we're diverting. Wanted to get your thoughts on that prior to doing all the work.

Thanks for always chiming in here, we appreciate all the help!

 

[Husqy510]

Water flows thru the tubes. Oil flows around the tubes.

Are you sure about the flow? I thought the oil went through the coils and the cooler is full of water. Our cooler has provisions for motor oil and drive oil.

I verified the gauge is working, and the oil temp rises quickly when cruising at anything above 3k. We saw 250 degrees after a couple minutes of cruising at 3500

 

[TexasJet]

I'm talking about the cylinder type cooler. They are 18" long and maybe 3" OD. That type is water thru the tubes and oil around the tubes. It has to do with heat transfer. The outer OD of the tubes have more contact surface hence more heat transfer from the oil to the water in the tubes. In the oil and gas industry the cooling medium always goes in the tubes.

 

[Husqy510]

Figured out our problem, it was a faulty sending unit. We started checking temps with a infrared gun and temps at the pan, cooler and filter were drastically lower. Installed a new sending unit and now the highest temps we've seen is 195

 

[Carlson-jet]

Figured out our problem, it was a faulty sending unit. We started checking temps with a infrared gun and temps at the pan, cooler and filter were drastically lower. Installed a new sending unit and now the highest temps we've seen is 195

It is always nice when somebody comes back and responds to a thread with the solution. Glad you ironed it out.

 

[rush1]

I also had a concern about my engine running too cold. After my last rebuild, switching to a roller cam which creates less heat, I installed a Moroso restrictor washer in the thermostat housing. Never ran a thermostat since sand suspended in the raw water can screw those up. It still runs cool but not as cold as it used to. Moroso sells a pack with three different restrictor rings. I used the middle size, figuring if it got too hot I could go to the other less restrictive ring. Seems to work for me on my .030 over 454 v-drive Spectra 24xs daycruiser.
This right here is solid advise

 

[shan]

Are you sure about the flow? I thought the oil went through the coils and the cooler is full of water. Our cooler has provisions for motor oil and drive oil.

I verified the gauge is working, and the oil temp rises quickly when cruising at anything above 3k. We saw 250 degrees after a couple minutes of cruising at 3500

Engine speed drives oil temp, plain and simple. Some people get all exited over oil temp, and I don't know what kind of oil you're running, but 250º F is not a concern with any oil. When you get around 300º F it's a concern. Cold water and hot oil is the best case scenario assuming the engine has had the clearances set for the lower water temperature.