New Temp Question - 3.7 Merc

[ewpvic]

I ran the boat for about 30 minutes yesterday with a different TS (older). In the water and on the muffs it would get to what appears to be 190 deg, however, when I used my laser therm on the temp send, it read a wonderful 165~170. WTH? Is my gauge THAT far off? CAN you calibrate? Am I measuring temp at the wrong place or could the laser therm be that wrong?

Boat ran flawless and to my nose, it didn't have that "hot engine smell". I just don't want to blow head gasket.

 

[Eric 3.7LX Alpha 1]

Read this write up from Auto meter, a huge gauge company. Very good explanation in it.

How old is the impeller in the drive?

http://www.autometer.com/tech_faq_an...x?sid=1&qid=57

 

[ewpvic]

It will be 1 day old today (gonna check/change it this morning). Good read, and as I expected (surface temp).

Any accuracy in the radiator type caps with therm built in? I have seen some guys on here that have tried using them.

As always, thanks Eric.

I DO love this little power house. Sips gas and runs mid 40s. What more could you ask for.....???

 

[Eric 3.7LX Alpha 1]

I use one of those thermocaps and I really like it. I feel it is very accurate and is very close in readings to my dash gauge. I still keep my original cap on the boat incase anything goes wrong with the gauge cap.

and easy to winterize

 

[ewpvic]

It will be 1 day old today (gonna check/change it this morning). Good read, and as I expected (surface temp).

Any accuracy in the radiator type caps with therm built in? I have seen some guys on here that have tried using them.

As always, thanks Eric.

I DO love this little power house. Sips gas and runs mid 40s. What more could you ask for.....???

 

[ewpvic]

It will be 1 day old today (gonna check/change it this morning). Good read, and as I expected (surface temp).

Any accuracy in the radiator type caps with therm built in? I have seen some guys on here that have tried using them.

As always, thanks Eric.

I DO love this little power house. Sips gas and runs mid 40s. What more could you ask for.....???

 

[ewpvic]

Eric - do you know the part number for the Thermocap? Sorry for the double/triple posts

 

[Eric 3.7LX Alpha 1]

I don't remember what the pressure rating of the factory cap is off the top of my head... They sell those thermo's in different psi ratings.

http://www.summitracing.com/search/product-line/mr-gasket-thermocap-radiator-caps?PageSize=50

 

[ewpvic]

I'm thinking of replacing the TS too, or should that make a difference? (with it being a closed cooling system, I would think so).

I appreciate all the help Eric.

 

[ewpvic]

I may have found the biggest culprit : Tstat not opening until just shy of 180 deg.

 

[Eric 3.7LX Alpha 1]

and that is with a 160°F stat?

 

[ewpvic]

Yes sir.