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thermostat why or why not

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axkiker

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Discussion starter · #1 ·
Ok I understand the reason for having a thermostat in an engine which is in a car. It helps get the engine up to operating temp which burns the fuel more efficently etc.

I dont however get why you need one in a boat engine. Its not like they are efficient by any means. Since boat engines are ran so hard it seems that it would be better to trade some efficiency for a cooler running engine.

just currious.

thanks
 
#2 ·
Many cooling systems NEED one installed for the restriction to make the water go where it needs to. I tried my gen 1 alpha without one, and the engine ran hotter than with one. The cooling plumbing was designed to have one in there.

This is the reason you can get 120 t-stats.
 
Discussion starter · #3 ·
well i have a 454 and mine went out so i just threw it away and put it back together. I cant seem to find any ill effects from not havin it. runs cooler and seems to do just fine. Im just trying to see figure out if im missing something.

later
 
#8 ·
In addition to the mentioned avantages, one very imporant item has to due with the engine oil.
Marine engines in their enclosed and very humid conditions create a lot of condensation inside and outside of the engine block. The only way to remove this condensation is with heat. Operating the engine without a thermostat reduces internal oil temperatures and can lead to sludge as moisture will remain in the oil. Water and oil don't mix...
 
#11 ·
SHIP4BRAINS said:
IS that warm enough?
Click to expand...
Remember I am talking about huffer motors so I prefer to keep them cool. The nice thing about the restrictor washers is if I decide its not running warm enough,I can just change the restrictor to a smaller size such as 3/4 inch. If I am not mistaken Jeff runs his OuterLimits on cool side also. :winker:
 
#12 ·
no experience there so I wasn't commenting..just asking.

I have heard guys scream about swapping out a 195 degree T-stat and changing it to a 180 in automotive applications. I personally think 195 in a truck is nuts....but i couldn't tell you why, technically!
 
#17 ·
SHIP4BRAINS said:
COME ON CFM....YOUR OPINION PLEASE
Click to expand...
I'm trying to sleep, I mean work, over here. Shhhhh.


<a href="http://www.smileycentral.com/?partner=ZSzeb008_ZS" target="_blank"><img src="http://smileys.smileycentral.com/cat/7/7_11_4.gif" alt="Alarm Clock 2" border="0"></a>
 
#18 · (Edited)
Couldn't fall back asleep. Thanks. :dead:

Best performance from coolant temp seems to be around 120° F. One exception is some EFI motors, but that's only because of typical 'cold start' programming.

Oil must be at 180 °F before running under high load/rpm. Oil should be held between 215°-240° to #1 remove condensation and #2 stay within oil spec's to keep motor lubricated properly.

So...........it's more oil temp than anything else.

Remember, the water cools the metal inside your motor. The metal cools the oil. :D Yup, another oil cooler.

Many engines running no t-stat will not allow oil to warm up enough or it will take a very long time to do so. Remember, one should wait for oil temp to come up before putting the throttle down hard. And, then, of course, when one slows down, the oil temp drops right back down....fast !!!!

Summary:

A super happy marine engine will be running 110°-140° water temp and 215°-240° oil temp.


Thermostats in both the water system and oil cooler system will let temps come up faster + maintain proper temps if cooler's are large enough. :D
 
#20 · (Edited)
I agree that block temp has a direct affect on oil temp. I've proven it to myself. Some time ago site member Blur Thunder/BT suggested I go to a cooler tstat in the block, to lower oil temps. It worked.

Question assuming no tstat in the block.....and this is closely related to what 87Pachanga brought up.... during/after mid to high RPM cruise, or, during/after a hard romp, the rotating assembly warms up (as does the oil). When the rotating assembly warms up, parts expand. Pistons get hot so they must expand. With no tstat in the block, there will be little to no expansion or contraction of the cylinders. What affect does this have on piston to cyl wall clearance?

With a tstat in the block, the block will expand some as it warms up. And I'd guess that the cylinders would close up a few thousandths as the block heats up? If this is true, with no stat and no cyl expansion, it seems the pistons would be loose in the holes. Wouldn't this condition lead to wash down of the cylinders? Or would the rings compensate for that? And maybe premature wear caused by the pistons flopping around in the cylinders? Hhmmmmm......??? :D

BTW....I'm thinking in terms of a relatively stock NA engine or a mild build. Not exotic or SC.

now I gotta go take the trash out, so I can have the car next Sunday :p: :laugher:
 
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