Engine operating temp

[Road Head]

1994 Chaparral with 5.7L merc with Alpha I Gen II. My temp never gets above the 120-130ish mark - it seems to run great though, no problems. I have been searching, but am finding conflicting info, some things say that range is ok, others state 140 for raw water cooled and then there is the ever present 160, which is optimum for an engine. Anybody know the appropriate range? Also, if anybody knows the part number for the thermostat (in case I need to replace it), would you mind posting it.

Thanks

 

[bruceb58]

Re: Engine operating temp

Just because your gauge says that temp doesn't mean it is correct. They are notorius for being a little off.

 

[Reel Poor]

Re: Engine operating temp

Can you post your engine serial number ?

 

[Road Head]

Re: Engine operating temp

Just because your gauge says that temp doesn't mean it is correct. They are notorius for being a little off.

I was concerned about that as well.

Can you post your engine serial number ?

I have it at home, Ill get it tonight.

Since my boat is 13 years old, would it be a good idea to go on and replace the thermostat anyways? They seem relatively inexpensive.

 

[Don S]

Re: Engine operating temp

120? to 130? is too cold no matter what engine you have. I would suggest you get one of those IR temp guns to verify, but yes, you also need to check that you infact have a thermostat and that it is working properly.
If you click here and scroll down near the end of the list, you will find "Standard Cooling System" . Check out the 3 designs and find what you have. The stat temps vary over the 3 designs, but are 140? to 160? opening temps.

 

[Road Head]

Re: Engine operating temp

120? to 130? is too cold no matter what engine you have. I would suggest you get one of those IR temp guns to verify, but yes, you also need to check that you infact have a thermostat and that it is working properly.
If you click here and scroll down near the end of the list, you will find "Standard Cooling System" . Check out the 3 designs and find what you have. The stat temps vary over the 3 designs, but are 140? to 160? opening temps.

Thanks for the link. At this point, Im not sure which of the three designs I have. I can look and see next time I am on the boat. The only thing I am sure of is that it is raw water cooled...there is no antifreeze or otherwise closed system, the only coolant is water sucked up through the sterndrive.

My guess is that those standard designs are closed cooling, half and half (fresh water), and raw water (what I have), I just dont know which is which comparing the three pictures.

 

[Don S]

Re: Engine operating temp

Standard cooling means it is raw water cooled not closed cooled.

 

[Road Head]

Re: Engine operating temp

Standard cooling means it is raw water cooled not closed cooled.

Well dang, thats even more confusing then