• Welcome to the Checkmate Community Forums forums.

    You are currently viewing our boards as a guest which gives you limited access to view most discussions, articles and access to our other FREE features.
    By joining our free community you will be able to:

    » Interact with over 10,000 Checkmate Fanatics from around the world!
    » Post topics and messages
    » Post and view photos
    » Communicate privately with other members
    » Access our extensive gallery of old Checkmate brochures located in our Media Gallery
    » Browse the various pictures in our Checkmate photo gallery

    Registration is fast, simple and absolutely free so please, join our community today!

    If you have any problems with the registration process or your account login, please contact support by clicking here or by using the"contact us" link at the bottom of the page.

THERMOSTAT WHO KNOWS

Big Red

Big Red

Well-known member
Just wanted to know who runs what. I am running a big block with Aluminum heads and a 180 T-stat and fresh water cooling. Does anybody have a better idea or do you chuck your T-stat in the trash. I have run my boat with and without it seems to run to cool without. But I am always worried about the T-stat hanging up.

Big Red N.C.
 
Keep it in!

With the thermostat out the engine runs too cold longer which is not good. Also, with the thermostat removed the coolent can continuosly cycle through the block and never get cooled and eventually overheat the engine.

Mike
 
I agree, never run without a thermistat. The engine will run too cold. The oil temps will have a hard time getting up as well. Next thing that will happen is condensation in the oil.

I runa 540 with aluminum heads and closed cooling. I run a 170* t-stat. water temps stay at about 180* even after running hard. Wait a minute, all my runs are hard....:D
 
I have been running a 180. I ran the boat a couple of weekends without the T-stat, it got stuck and I pulled it out at the lake. I put a new 180 back in because it ran to cool. Should I change it to a 170.

What is the best brand of T-stat to buy.

Big Red N.C.
 
There is not much difference between 170& and 180*. It should be fine eithre way. I like to use AC Delco or Mercury T-Stats.
 
Most auto parts stores probably carry a Stant Superstat (not a standard Stant - they're cheap). The Superstat has a stainless body with a brass plunger. I know Advance Auto parts carries those in a 160 and 180 degree models. They may be able to order a 170 if that was what you really needed.
 
Yea, here you go:

"Stant® SuperStat® premium thermostats use a patented v-notch, non-linear design valve to stabilize engine temperatures and allow the engine to warm up faster. This feature reduces overcooling when the thermostat opens, and overheating when the thermostat quickly closes with the rush of cold coolant, thus reducing thermostat cycling. The advantages of a quicker warmup are prolonged engine life and improved fuel economy and emissions. The heavy gauge stainless steel construction and spring offer longer life and maximum performance."

$7 at Advance. I would guess that's a lot cheaper than one sold as a Marine unit and it sounds like it should be perfectly suited for marine use unless someone knows something else.
 
as far as mercrusier goes, they claim there thermostat differs greatly from automotive.. and i do know if there thermostat isn't in a newer engine thats under warranty, well it was under warranty.. all the new merc thermostats are made of stainless steal, and i've really not paid a whole lot of attention to them, other than a long time ago in school i learned there was wax in the brass piston, that made it go up and down.. i've personally never seen the wax.. but i guess if it goes away it'll stick closed or open..
i've seen alot of different thermostats put in mercs, and most all ran well, the ones that didn't rosted ther exhaust manifolds, because, when you to the autopart store, you get a gasket with the thermostat, and not the plastic merc piece, or the brass one.. so alot of times you'll see 2 thermostats in an engine, and one is in the wrong place, and the other is stuck.. either way.. there is a cooling problem. or you'll see one thermostat, in the wrong place.. i say put em back where they belong, and don't worry about it.. a thermostat kit from merc is only 10 to 13 bucks.. to lil a money to worry about to get the wrong parts.. the brass or plastic piece are sold separatly, and are cheap too. 2 or 3 bucks i think
 
also with no stat in the piston rings will not heat up and seal right running a low temp causing some future problems or atleast that was what i was told when i built me 350 for my truck.
 
I agree Happy - If it's only $10 then use the Merc. Sometimes boat parts just frustrate me because many of them are the same, but the manufacturers brainwash everyone into thinking they are rocket science and charge 10 times as much as an automotive part.

Prime example is a fusebox I bought at Advance for $6-8 and it is $40 at a boat place in different packaging. Same casting and everything. No doubt in my mind it's the same piece. For some reason anyone who owns a boat is treated as if they have money - and I can promise you I don't....
 
vinny p. said:
I agree, never run without a thermistat. The engine will run too cold. The oil temps will have a hard time getting up as well. Next thing that will happen is condensation in the oil.

I runa 540 with aluminum heads and closed cooling. I run a 170* t-stat. water temps stay at about 180* even after running hard. Wait a minute, all my runs are hard....:D
Click to expand...

Vinny Im about to inspect a friend of mines boat for what may be a similar problem.
he just bought the boat in February (281 maxxum w/twin 350ci) the engines are rebuilt with supposedly 40hours each.
we took it for a ride two weeks ago on a Friday and I noticed the temp gauges were not showing any temp. I checked the gauges and they are working properly.With bay temps around 38* the engines were sweating so bad on the outside of the block you could watch the water bead up and roll down the engine.
Not knowing what was done to the engines I told him not to run it again until he checked to see if it had thermostats in it.Well...........................
on Sunday him and another friend took it back out and ran it hard. Now he is complaining of water in the oil. I went down and looked at it and one engine is one quart over full and the other is at full. There is no foaming of the oil to speak of (very little in the breather caps)but the oil is light gray to cloudy not clean like it was when I was out on it.now I know there is plenty of reasons oil can be contaminated but how much condensation can a engine trap in its crankcase if it is running below operating temp? Just looking for some opinions before I start working on it.
 
That is a hard question to answer. Condensation can accumulate enough to turn good oil to bad. If left alone and not repaired, it could cost an engine. I would bet that the inside of the valve covers are loaded with water as well. Dont let it sit. Change the oil right away. Check the cooling system out. Make sure the correct thermistats are in there. Do those engines have that check ball system in the thermistat housing? The one that sends water to the risers? If so, make sure they are not rotted out and are working properly.

Good Luck.
 
If oil does not drain well fill block with diesel fuel to breakdown the water/oil mixture. The diesel will break it down into something that can be easily drained or sucked out. It may take you a few oil changes to get all the water out.

Good Luck
 
vinny p. said:
That is a hard question to answer. Condensation can accumulate enough to turn good oil to bad. If left alone and not repaired, it could cost an engine. I would bet that the inside of the valve covers are loaded with water as well. Dont let it sit. Change the oil right away. Check the cooling system out. Make sure the correct thermistats are in there. Do those engines have that check ball system in the thermistat housing? The one that sends water to the risers? If so, make sure they are not rotted out and are working properly.

Good Luck.
Click to expand...

The guy that owns the boat is not a mechanic but he can handle the basics so I told him to change the oil and filters and to pull the thermostat housing to see what's in there. I have a feeling with engines running as cold as they were there are no thermostats in the engines.Once he has new or correct thermostats in place and fresh oil and filters I will go down and inspect it this weekend.
The engines do not have the check ball style housings the have cross overs installed.
 
You must log in or register to reply here.
Back
Top