Water temp

[Big Inch]

I'm curious what everyone's thoughts are on acceptable low water temps. I just had my motor rebuilt and after getting it together my temps were a little bit high. The impeller that was in it fell apart when it was first started up. I guess it got dry sitting around. So anyways it was replaced but apparently back flushing it did not remove all the debris. When I pulled off the first inline cooler it was packed with rubber and after removing it the motor runs extremely cold. 95-100 degrees under load. I have always thought this was too cold and would not allow proper combustion in the chamber and that the temp should be brought up. I purchased a 160 degree thermostat, drilled two 1/4 inch holes around the edge of it so it would have consistent flow and reinstalled it. I spoke with the guy that installed the motor for me and asked him if there was a better way to control the temp on the motor and he stated that I should remove the thermostat and just let it run at 95 degrees. He said that the belief of this being too cold is an old school way of thinking and that the motor benefits from the additional cooling and will create more power. That as long as it is not so cool as to create condensation in the oil that it is fine and actually preferred. I'm sure he has way more knowledge in this area then I do but I just wanted to get some more opinions before I remove the thermostat.
thanks for your help

[HALLETT BOY]

as long as oil temp gets above 212 degrees, you should be fine . as the oil gets
that hot, it creates steam from any moisture in the oil and it goes out the breathers or into the pcv...

[Big Inch]

Unfortunately I don't have an oil temp gauge to measure this. I am not seeing any signs of condensation in the oil but I'm not sure what to do about installing a temp gauge. Don't you have to tap into your oil pan to read this accurately?

[H20MOFO]

That Sounds Way Low To Me. 95* I Know Jet Boats(with Out Therm. Kit) They Have To Set Your Temp At Idle And When You Go Then It Drops Way Down. I Guess What I'm Askin Is What Does Any OnE Else Run ?(temp Wise?) . I Have A Jet Thats Fairly High Compresion And On 110 And It Hates To Be That Cold. Seems Much Happier Around 140-160*

[cfm]

as long as oil temp gets above 212 degrees, you should be fine . as the oil gets
that hot, it creates steam from any moisture in the oil and it goes out the breathers or into the pcv...
Yes, oil temp is more important than water temp.
We need to make sure oil is at min of 180 before we get hard on throttle. 212 min to keep water out of oil, and 250-260 max for oil and motor longevity.
The cooling system effects the oil temp big time. A too cold coolant temp may make your oil temp too cold or take too long to warm up. All applications react different so we must check if this is not a 100% OEM engine and 100% OEM cooling and oil system.
Most marine engines that do not use t-stat will have oil cooler with t-stat so that oil will climb to proper temp faster. However, I've seen in colder water this can take a long time to get there too.
=======================
Do you have a pic of your cooling system ? If not, can you describe it especially if uses recirculating pump or a crossover system.

[centerhill condor]

I only run a stat in the non summer months.
CC

[Big Inch]

Cfm I will do my best to describe my set up. First of all the motor is not oem nor is any part of the cooling system except for the seawater pump. It is a 598 ci merlin block,heads,intake manifold and is normally aspirated with about 10.2-1 compression. I run about 75% pump gas 92 octane and 25% 110. The cooling system is plumbed in this order. It draws water from my bravo 1 drive and goes directly into the mercruiser seawater pump (no sea-strainer.) It goes first to the aftermarket steering fluid cooler then to the aftermarket oil cooler. It has a remote located HP-1 oil filter. After the oil cooler it is routed to a T fitting that feeds the lower section of my Imco exhaust manifolds, entering at the rear of the manifolds. Exiting the front of the manifolds it goes through braided lines into the front of the motor on it's corresponding side. So essentially there is no crossover. There is an individual line going from the left side of the exhaust manifold and entering the left side of the block and 1 from the right exhaust manifold into the right side of the block. From there the water flows through the block and up into the manifold and exits there from the thermostat housing and splits again to each riser and out the tips.
Please let me know if you need anything explained in more detail. I would post pictures but the boat is at the river and I am at work looking forward to the weekend :)

[Big Inch]

Found some pictures that might be of help.
Power steering fluid cooler circled in red.
http://img528.imageshack.us/img528/7070/coolerzc7.jpg (http://imageshack.us)
Oil cooler and lines circled in red.
http://img113.imageshack.us/img113/6995/waterlines1fv5.jpg (http://imageshack.us)
Side view of motor
http://img69.imageshack.us/img69/7509/engineie9.jpg (http://imageshack.us)

[Big Inch]

Yes, oil temp is more important than water temp.
We need to make sure oil is at min of 180 before we get hard on throttle. 212 min to keep water out of oil, and 250-260 max for oil and motor longevity.
The cooling system effects the oil temp big time. A too cold coolant temp may make your oil temp too cold or take too long to warm up. All applications react different so we must check if this is not a 100% OEM engine and 100% OEM cooling and oil system.
I forgot to comment on this earlier. I have no way of measuring the oil temps at this time. I'm open to suggestions. As of now I know that I was getting steam out of the breathers when it was running hot, obviously. To recap, it was running hotter due to the plugged cooler. I will have to check on that this weekend now that it is running cooler. While running at the low temps of 95ish degrees the oil pressure was consistent with what I believe it should be making. 55ish pounds at constant throttle around 4000 rpms. I am running Kendal 50 wt oil. I believe this indicates at least fairly warm oil temps because if the oil was not heating up enough I believe I would be seeing much higher pressure at higher rpms due to the cooler/thicker oil. It is not showing signs of overheating the oil ie.... losing pressure at rpm or under load. I have a mechanical oil pressure gauge hooked up temporarily so that I can get a reliable picture of what the oil is doing. This was done because I do not have a oil temp gauge and I am open to suggestions on how to better measure the oil temps.

[HALLETT BOY]

Why so many adapters on that oil cooler ????

[Big Inch]

Why so many adapters on that oil cooler ????
I'm sorry but I do not know how to answer this. Could you please give me more detail? I don't know of or see any adapters on my oil cooler. Maybe if you describe what you are seeing by the picture I can better answer.

[cfm]

Good description, thanks.
Okay, they route it to the exhaust manifolds and then to engine so as to 'pre-heat' the water going in the engine a little bit.
Again, I would not worry about coolant temp that much. I would check oil temp. If you do not source oil temp from pan (IMHO the best place) I would do it before the oil goes to the cooler. You can put AN fitting in that has a port to 'T' in oil temp guage.
With no condensation, you probably don't have a 'too cool oil' issue, but who knows when oil is at proper temp to go WFO and also what your max temps are.

[HALLETT BOY]

I'm sorry but I do not know how to answer this. Could you please give me more detail? I don't know of or see any adapters on my oil cooler. Maybe if you describe what you are seeing by the picture I can better answer.
Look at your first picture, the circled oil cooler...now look to the right of the cooler, it looks like about 4 different adapters at the oil inlet...

[cfm]

I forgot too mention - a water psi guage (plumbed in block or just at very entrance to block )should also be used when using systems like this or any other for that matter with a fast I/O. You really don't want more than 25psi block psi when at WFO and top mph.
So............oil temp guage and water psi guage and go ripp'm. LOL.

[Big Inch]

Look at your first picture, the circled oil cooler...now look to the right of the cooler, it looks like about 4 different adapters at the oil inlet...
Aww now I see. That is not the oil cooler. The oil cooler is in the second picture, circled in red on the lower right side of the picture. Polished aluminum cylinder mounted to the block of the motor. The cooler you are referring to is the steering fluid cooler. Those things on the right side are not adapters or lines entering the cooler. There you have the wire loom, batter cables, and some water lines that are just laying there since everything is disconnected. That cooler has 1 water line entering and exiting and the high pressure steering fluid line entering and exiting as well.

[Big Inch]

Good description, thanks.
Okay, they route it to the exhaust manifolds and then to engine so as to 'pre-heat' the water going in the engine a little bit.
Again, I would not worry about coolant temp that much. I would check oil temp. If you do not source oil temp from pan (IMHO the best place) I would do it before the oil goes to the cooler. You can put AN fitting in that has a port to 'T' in oil temp guage.
With no condensation, you probably don't have a 'too cool oil' issue, but who knows when oil is at proper temp to go WFO and also what your max temps are.
Couple things.
Yes the water is pre-heated thru the exhaust manifold.
I hadn't thought of installing a gauge in the method that you are describing but it sounds like a great alternative. Only problem is that the cooler is not plumbed with lines it is attached to the block where your oil filter normally goes and then under that it has 2 remote lines that go to the remote oil filter. I wonder if the oil goes through the filter first or the cooler first. If it goes through the filter first I could run the T adapter there. It is a major task to remove this oil cooler though in order to try and figure out if it cools the oil before the filter. Any input on whether or this sort of setup normally would? Is it possible to tap the oil pan for a fitting to install a gauge there or is that only done with it off because of the risk of metal shavings entering the oil?

[Big Inch]

I forgot too mention - a water psi guage (plumbed in block or just at very entrance to block )should also be used when using systems like this or any other for that matter with a fast I/O. You really don't want more than 25psi block psi when at WFO and top mph.
So............oil temp guage and water psi guage and go ripp'm. LOL.
Another good point. Looks like my dash may be getting a face lift soon :rolleyes:
Next question: If it has too much pressure how do I regulate this? I know on my jetboat I had a valve on the intake line that you could open or close more to adjust the pressure. Maybe this would bring up my water temps as well.:idea:

[cfm]

A person in another forum (same topic) suggested drilling and tapping the oil pan drain plug for oil temp sensor since none of us really use the drain plug while in the boat.
Something you would think I would have thought of a couple of eons ago, but didn't. It's a great suggestion BTW !

[Big Inch]

A person in another forum (same topic) suggested drilling and tapping the oil pan drain plug for oil temp sensor since none of us really use the drain plug while in the boat.
Something you would think I would have thought of a couple of eons ago, but didn't. It's a great suggestion BTW !
Yeah but then you sacrifice the little magnetic tip in the center of the plug :D Plus I have an drain line on mine so still not going to work for me. Actually the line goes out the side maybe it would work.

[Big Inch]

Update after running the boat over the weekend.
I ran the boat with the 160 thermostat installed. Took a hand held pyrometer with me to take some heat readings and what I found was that after running hard with the water maxxing out at about 170 degrees water temp I was getting oil temp readings of 222 degrees. To me this seems to be pretty close to optimal temperatures and I am assuming that if I remove the thermostat and the water temps drop down by over 70 degrees that it is pretty safe to assume that this will drop my oil temps down below 210 degrees. Assuming this to be true. I would like to find a way to raise the water temperature in the motor without the use of the thermostat. My only experience with this was on my jet boat where I plumbed a valve that would restrict the flow to the motor. I'm wondering if this could be done on the intake line on my boat and if this is the best way to do this.

[cfm]

On a performance engine under load I'd prefer 120-140 water temps. Your oil temp is perfect.
Be careful with t-stats with your type cooling system - they can make water psi get destructive. I have personally seen things get nasty (ie:water leaks where you really don't want to see them) at 30+ psi. I tested a crossover system with t-stat on the dyno that went over 60 psi ! Results where enine teardowns. Therefore, 25psi is all I'd ever want to see and still feel comfortable.

[Big Inch]

Thank you for the response. Your help is appreciated.
Can anyone suggest a method for me to increase my water temps from 95 to 120-140 range without the use of a thermostat. My concerns with running a t-stat are exactly as Cfm stated and I really want to avoid having to run one.