Appropriate Thermostat temp

[RomanRegal]

Hi, I have a 1987 Regal 233xl. It houses a 5.7 Liter S/B 260 Hp. I run the boat on Lake Superior. Generally cold water. The boat has a 140 degree thermostat. Generally, in all types of cruising the engine runs cool. The gauage barely moves the quarter and half mark when running 3500 rpms. When the throrrle gets pulled back it will drop to a quarter on the guage. Would there be any advantage of installing a 160 degree thermostat. The engine is raw water cooled. Thanks Roman

 

[tommays]

Re: Appropriate Thermostat temp

R<br />thats a tough question because the main reason for the 140 thermostat is to control salt build up in saltwater areas which gets to be a problem around 160 deg<br /><br />hopefuly someone will have tryed it as i run in saltwater and cant<br /><br />tommays

 

[crazy charlie]

Re: Appropriate Thermostat temp

That raw water cooled motor calls for a 143 degree thermostat.That is just below the 1/4 mark on the guage.Thats what you should use.If the temp climbs as you cruise ,you may have discovered deteriorating manifolds and risers or you may need a water pump servicing.By the way,I have had several Regals and have been more than happy with them.The one I had closest to yours was a 255 ambassador which is almost the same as what you have but larger.What an aftcabin that boat had.T r e m e n d o u s!!!!!Hope you have the same luck that I had with mine.Charlie

 

[rodbolt]

Re: Appropriate Thermostat temp

hello<br /> most todays motors run a 160. I dont recall that lake superior had much salt . try the 160 and you may be happy with it. before trusting your gauge have it verified with a temp gun or at least some thermo-melt stick on the t-stat housing and intake manifold area just below the t-stat housing

 

[Lou C]

Re: Appropriate Thermostat temp

I have been running a 160 im my OMC (oe stat) in salt water with no ill effects so far, with raw water cooling.

 

[Boomyal]

Re: Appropriate Thermostat temp

If you are running in freshwater, I would go to a 180 degree thermostat. Manufacturers do not know what kind of water a boat is going to be used in so they install a 'salt water' thermostat.<br /><br />180 deg is much better for combustion efficiency and there would be zero negatives in using it in fresh water.

 

[Don S]

Re: Appropriate Thermostat temp

A good rule of thumb is to keep the engine the way the manufacturer set it up unless you know what you are doing.<br />If you want to run the engine at 180°, then put on a closed cooling system.<br />With the higher thermostat in an engine, you then have cold water hitting a lot hotter engine.

 

[SteveRay]

Re: Appropriate Thermostat temp

So is this a good rule of thumb if your in fresh water? <br />I have a 3.0L and have been reading this and scratching my head wondering if I should change my T-stat? Would it be beneficial for me running in freshwater only and raw water cooling system. My guage always reads a hair below 140

 

[RomanRegal]

Re: Appropriate Thermostat temp

Thanks for the input everyone, epcially on Thanks gving day. Crazy Charlie, the Regal is a great boat. I live in Milwuakee, but keep my boat at the apostle Islands. I think there are only two or three Regals in the whole area.<br />Roman