Cold natured motor on a cold winters day??

[oldboat1]

ed.

 

[phillnjack2]

ok now I will explain to those who have no idea how it works.
the water comes up from the water pump to cool the exhaust chest then up through the middle of the bock to the top then down into the head.s then from the heads to the thermostats then out.
now please dont try telling me the outside temp is going to make the slightest difference to a running engine once warm.
if it di the engine wouldn't last 1 hour with al the fluctuation you think it would. the thermostats are opening and closing all the time, not just open dump a load of water then close. the thermostats keep the temp in the engine at a certain level, that is how they work on these engines...it keeps the heat in and lets it out before it gets too hot. and you will not see a temp gauge going up and down because the thermostats dont fully open, unless mega hot.

according to your theory these motors would never build up temp when running in freezing cold water, and would boil on a hot day.


now as for the running in of the engine, this is not brand new, he has already put atleast 5 hours on the engine !!! so yes its ready to run flat out if he wants on
50 to 1.
me I would of run it one hour slow then opened it up to run at 2500 for 15 minutes then slowed down to 1500 for 10 minutes then give it full throttle for
2 minutes and repeat this for 3 to 4 hours all at 25 -1, then go to 50 to 1 ratio premix and run as per normal.

how long do you seriously think a 2 stroke powerhead needs to be run in ? ...

 

[oldboat1]

glad you have a work around for the QS, Sutor. Should expect steady temps with a good cooling system -- a little longer for Winter warm up, no doubt, but otherwise no significant difference in winter running. Shoot temps at the top of the heads when checking.

Corrosion can be a problem if salt water running. Would recommend flushing to keep corrosion at bay, but that's just standard. (Temp. fluctuations resulting from sticking/carroded thermostats are pretty easy to spot).

Rich running will likely produce more l.u. exhaust nastiness when winter running, probably another reason for flushing if you can.

 

[flyingscott]

I am not going down that road with you I run these motors in cold weather and water all the time they do not heat up as much as they do in the summer. I can only lay the facts out there i can't make anyone believe them.I will say this my mercury 25 has the tattle tale attached directly to the thermostat in cold water the the flow. trust me that thermostat opens and closes all the time. As far as breaking in a 2 strk as long as the manufacturer says as they are the ones doing the warranty.

I guess for me I am wondering how you are pre heating the 42 deg water coming into the motor to prevent it from it from making the motor run cooler. My car runs cooler on winter days with a closed cooling system I am wondering how an outboard doesn't.

 

[sutor623]

ok now I will explain to those who have no idea how it works.
the water comes up from the water pump to cool the exhaust chest then up through the middle of the bock to the top then down into the head.s then from the heads to the thermostats then out.
now please dont try telling me the outside temp is going to make the slightest difference to a running engine once warm.
if it di the engine wouldn't last 1 hour with al the fluctuation you think it would. the thermostats are opening and closing all the time, not just open dump a load of water then close. the thermostats keep the temp in the engine at a certain level, that is how they work on these engines...it keeps the heat in and lets it out before it gets too hot. and you will not see a temp gauge going up and down because the thermostats dont fully open, unless mega hot.

according to your theory these motors would never build up temp when running in freezing cold water, and would boil on a hot day.


now as for the running in of the engine, this is not brand new, he has already put atleast 5 hours on the engine !!! so yes its ready to run flat out if he wants on
50 to 1.
me I would of run it one hour slow then opened it up to run at 2500 for 15 minutes then slowed down to 1500 for 10 minutes then give it full throttle for
2 minutes and repeat this for 3 to 4 hours all at 25 -1, then go to 50 to 1 ratio premix and run as per normal.

how long do you seriously think a 2 stroke powerhead needs to be run in ? ...

Phil,

First off, Evinrude calls for a 10 hour break in.

Secondly, this motor is a looper. You keep mentioning the thermostat covers at the bottom of the head, as in crossflow. These loopers have their thermostats up high.

I am not trying to argue with you, but you are incorrect about the cooling system. Now, if we are talking about idle speeds, you are spot on. The thermostats have NOTHING to do with regulating the temperature of the engine at higher RPMS. ABSOLUTELY NOTHING!!! The thermostats on these motors regulate the head temps at low pressure/rpms.

Once the engine gets to a certain RPM, the waterpump pressure forces the bypass valves open, blowing water right past the back of the thermostat. The rubber grommet that the thermostat sets in also serves as a water pressure valve. Once the water pressure exceeds the force of the spring holding that bypass valve closed, the water will flow up the block, through the heads, and out the exhaust.The temperature of the thermostat has NOTHING to do with this process. The water cannot stay in the heads to warm up when you are at high rpms.

To make it even harder to keep these motors warm when the water is cold, water is CONSTANTLY flowing up into the block, and back down the exhaust ports of the cylinder, and down the exhaust housing in the leg.

Needless to say, as Scott has pointed out many times, since there is no closed circuit to regulate the temp of the cooling water in an outboard system such as this one, the temperature of the motor is directly proportionate to the temperature of the water coming in and out of the block. At idle, the motor has somewhat of a closed circuit, because the heads trap the water to warm it to 140 degrees. But even at idle, the cooling water is flowing in the block and down the exhaust ports and out.

There is really nothing to argue about here.

 

[Fed]

I have to say you have the most interesting threads sutor.

Out of interest I was looking at the thermostats at the BRP website & it struck me they have 2 different springs that hold the thermostats in & I guess act as a by-pass valve. One spring for suffix A motors & one spring for suffix C motors, could they be different strengths to achieve earlier or later by-passing depending on where the motor is being shipped to (climate).

BTW, did you check the temps right on the heads or on the water covers?

Why not simply up your in gear idle to 700 RPM, surely that would eliminate most of your warm up problems.

Anyway, great thread.

 

[sutor623]

I have to say you have the most interesting threads sutor.

Out of interest I was looking at the thermostats at the BRP website & it struck me they have 2 different springs that hold the thermostats in & I guess act as a by-pass valve. One spring for suffix A motors & one spring for suffix C motors, could they be different strengths to achieve earlier or later by-passing depending on where the motor is being shipped to (climate).

BTW, did you check the temps right on the heads or on the water covers?

Why not simply up your in gear idle to 700 RPM, surely that would eliminate most of your warm up problems.

Anyway, great thread.

Thanks! I am just a thinker and a constant tinkerer. I also love this forum and the knowledge and personalities that are on this board. Hard to get this kind of feedback anywhere else on the planet!!

Interesting about the two types of springs. I'll have to look into that. I checked the temp at the thermo covers and the heads. Heads are significantly warmer (110 after being on plane) than the thermo covers(70-80 degrees after being on plane.)

I did up the idle Some and it seemed to help. I think having a properly functioning quickstart would solve this issue for many reasons. Even Clarke himself (head honcho fromCDI ) could not figure out why my QS was acting up, and he tested my whole
Ignition system. So I just disengaged it.

 

[oldboat1]

It's another interested thread as Fed suggests.

Sutor -- 110 at the head looks better, IMO. From your description, that would not be a thermostatically controlled temp(?), though, and I'm trying to get my head around that. Is it a constant temp, and if so how is it held constant? (Maybe it would simply be like operating with a wide open t.stat -- or maybe none at all, like on the old '50s Big Twins I liked to run.)

Flying Scott -- I think I understand outboard t.stats to work a bit smoother than you describe. Incoming 42 degree water (in Sutor's case) would get a controlled mix with heated block water, and released through the cooling passages at the rated temp (at least at idle I guess.) On the other hand, the sticking t.stats I described do not operate smoothly, and can produce an uneven mix -- fluctuating temps while everything else (e.g., rpms and raw water temp) remains constant. If they stick shut, of course, the engine overheats. Stuck open (or removed completely), the temp is whatever you get based on the operating temp of the engine, mediated by the incoming raw water. It's a little unpredictable, but safe when sea temps are low -- or so the theory goes, I think. The culprit is salt corrosion.

 

[flyingscott]

It's kinda funny people don't worry about the engine running at 170 deg in the summer But if it loses 30 deg when it's cold out people lose there minds and something has to be wrong

 

[oldboat1]

[edit.]

 

[phillnjack2]

I shall explain once again for those who cannot understand plain English. how the v4 water system works......
the water from lake /river / sea goes from water pump up to the adaptor plate that is warming up due to exhaust gases running through this,.
the adaptor gets hot enough to give your burns that would need hospital treatment , it like the manifold on your car !!! then it goes into the extremely hot
exhaust chest to keep that cooler and the now warmer water travels up through the centre of the block.
It then goes all the way to the top of the engine block , and then and only then goes down into the cylinder water passage ways and cylinder heads. at the bottom of the heads it then travels to the thermostats then it goes out through the hot adaptor and out of the engine.. by the time the water goes through the exhaust chest it is already a lot warmer than the river/lake etc that its come from. now the water in the cylinders gets warmed to 143 deg F before the thermostat open. as soon as this opens a small amount of water goes out and a small amount comes into the head and warms to 143 then stats open etc etc etc...if this is not happening then something is very wrong.
if the water does not reach the temp of the thermostats a small amount will go through the by pass valves in the thermostat block due to the pressure from water pump impeller.

Your 25hp mercury its not only a totally different system, that should keep a decent temp too. but its no v4
.
As far as auto engines with a complete enclosed cooling system, these should run at around 88dec C depending on the temp stamp on the thermostat used.
you can buy summer thermostats for extreme hot country's like the middle east for example.
BUT all auto engines should maintain the temp on the thermostat.
if you have a car or truck built since 1980 that has an electric cooling fan and it dont keep temp the same in winter and summer then you have a problem.
and that needs to be rectified quickly before premature engine wear.
Running too cold is as bad as too hot, metal expansion was taken into account when the makers put thermostats in the cooling system.
it is surprising how just a few degrees wrong can wear an engine out very quick .

 

[flyingscott]

Why do cars run hotter with the air conditioning on according to you it's impossible. It's amazing to me how little people know about cooling systems. If the motor Got to 143 why would the thermostat let out only a little water as long as that water is 143 deg it will stay open. It won't close again until it gets cooled down BY 42 DEG WATER. Really only a few degrees can kill a motor what about all the motors from the 50s and 60s that do not have thermostats that still run and run in the summer and winter.. How is my 25 hp mercury different a waterpump ,block and thermostat not that much different. The thermostat only opens at a certain temp that is not the operating temp of the motor. The thermostat just makes sure it gets to a decent temp. Why does it matter how many cyl it has does the waterpump know that all it knows is to pump water. Can the thermostat tell 140 deg water in a 4 cyl from 140 deg water in a 2 cyl according to you it can. Why do motors run hotter when they work harder. My 1961 5.5 hp outboard had an optional thermostat ran fine with out it no premature wear on that. Optional means it could have one installed but not necessary.



I can't say it any plainer than that But don't let the facts get in your way

SUTOR I am sure your motor will give you many years of service good luck with it

With that I am out of the rabbit hole

 

[sutor623]

We all understand how an adapter plate works. The point is, that in 42 degree water, the motor WILL RUN COOLER, end of story. I am not talking about at idle. At idle the heads will stay between 130-150 degrees. If not there is an issue. When these loopers run at cruise or WOT, THE THERMOSTAT HAS ABSOLUTELY NOTHING TO DO WITH THE TEMPERATURE OF THE MOTOR!!!! NOTHING!!!! The water pressure will bypass the bypass valves in the cylinder heads, overpowering whatever temp regulation that the thermostats control. That's not to say that the engine won't stay warmer while it is running, because it will. But to expect the heads to stay at 143 degrees while running at cruise in 42 degree is so far off its not even funny.

 

[sutor623]

SUTOR I am sure your motor will give you many years of service good luck with it

With that I am out of the rabbit hole

Thanks brother, Im out too. Thanks for all your help on this board.

 

[phillnjack2]

some people seriously need to learn about engines. please watch this and learn something

weather condition = nice bright 45 degree day in may England 2013, the year we had crap weather and rain most of it with floods and cold weather .

water butt being used with a constant flow of cold water from hose pipe due to leaking water butt.
home water pressure around 40 psi and very cold.
you will notice the engine is running at 950 to 1,000 rpm due to fast idle in neutral. ...the engine temp is 63 degree and rising ..
you can see this in the video just after seeing the tacho and yes the temp gauge is very accurate to within 1 degree either way. also notice on
this engine while running the bypass reliefs are slightly open letting out a mist / spray. dirty stat bypass housing.
then engine has only just been started after being in garage for a month without use.



By the way our water in our rivers dont get much above 50 at anytime during summer, and may in England is definitely NOT summer..

 

[flyingscott]

We need to learn about motors !!!!!!!! YOU STARTED A BRAND NEW MOTOR WITH NO WATER ON THE WATER PUMP.

 

[dingbat]

WELL I AM NOT THE ONE THAT INSTALLED A 120 DEG TEMP GAUGE WHAT ARE YOU GOING TO DO WHEN IT OVER HEATS GUESS !!!!!!!!!!!!!!!!

Ugh, stop yelling and put your glasses on.... Under what circumstance is his motor going to exceed 120 degrees centigrade?

 

[flyingscott]

That was my bad on the centigrade. To bad we never saw the thermostat open and what that does to the temp. I did the conversion you were at 140 plus should have been open.

 

[flyingscott]

I apologize for the mistake on the temp gauge that was on me but in all fairness I am used to american gauges that read in Fahrenheit. I am really out this time it's to hard to take seriously any more you believe what you want.

 

[oldboat1]

I apologize for the mistake on the temp gauge that was on me but in all fairness I am used to american gauges that read in Fahrenheit. I am really out this time it's to hard to take seriously any more you believe what you want.

Good demo, Phillinjack -- shows pretty clearly that ambient temp/cooling water temp. is not finally critical. It's also a good description of working thermostatic control with the cold temps. (Nice rig, by the way.)

Flying Scott apparently wants to say the t.stat is going to close when hit by super cold raw water ("slam shut" was the description, I think). In fact, a working thermostat is going to gradually mix the colder incoming water to achieve the rated temp. It's a basic misunderstanding of t.stat control -- not sure why, as it's not rocket science. The demo helps.

Additionally, Stant gives a pretty good explanation of basic t.stat function, among others -- describes the gradual opening at the rated temp, for those who don't seem to understand that, with full open maybe 15-20 degrees F above the rated temp. As usually understood and accepted, It continuously (and unobtrusively) cycles within that range to do the job:

http://www.stant.com/index.php/engli...s-thermostats/

In any case, there is no significant issue in achieving or maintaining engine heat despite cold ambient temps or cold raw water temps, in keeping with your demo -- might take a little longer to warm up on a winter day, and the engine will cool down quicker when shut down, but typically that should be about it. That's not to say super cold air and water temps can't sometimes do battle with engine temps (add a 20 knot wind). Chasing ducks in winter can be tough, but we're not talking about critical loss of engine temps -- as long as pumps and t.stats do their jobs. (Which is where salt buildup could be a factor.)

Think the bigger influence is super heated ambient air and water temperatures -- not much more a t.stat can do mechanically when it's fully open. But that's probably a different story. The challenge with thermostatically controlled systems is to hold heat down with warm cooling water (as in 85 degree F lake temps). Once they are fully open there is not much more to be mechanically done. Additionally those bypass mechanism releases (springs) on the thermostat assembly apparently have a history of being too strong for pressure at high rpms, so a weaker version was available (as posted). Some guys shorten the springs so the release opens quicker for more cooling.