What water temp are you guys seeing on your 525's?

After a few outings my highest water temp has been around 150*. I thought this motor has a 160* t-stat? My 454 Mag MPI, and 496HO always ran 170ish regardless of the outside air/water temps.

I am seeing pretty high water pressure readings too. At speed, I'm seeing 25-30psi.

Anybody have 525's???

Dave, if you are reading your dash analog gauges for temperature it is very common for these to be off as much as 10 degrees or so. You should check the engine with a scan tool at max. temp use and see what the engine ecm is recording. Also, obviously the temperature of the air and especially the water will have a big affect on the engines actual final operating coolant temperature.
About the only other things that could affect coolant temperature would be the thermostat sticking open or the oil temperature thermostat in the oil block adapter also sticking open, but that's pretty uncommon.

Best Regards,
Ray @ Raylar

My 525s run about 150 on the gauge. Oil temps get high enough to cook off moisture. Never checked data stream to see what temp ECM was seeing.

Thanks Guys!

Ray, I'm getting my numbers from Smartcraft and Diacom.

Sounds like my temp is right on with what dcd is saying too.

I don't suspect I have any issues, the boat is new to me and I'm trying to establish a baseline. I just figured it would run close to the same temp as my previous MPI motors.

I believe my guage says about 160.

Dave,
keep in mind that the water pressure is measured at the oil cooler, the highest restrictive area in the water system. Livorsi is coming out with a water FLOW gauge that will be the best method to assure good flow of water through the motor, especially for the exhaust.

Is there any danger of excessive water pressure? How much is too much? I have a DWP drive, going to a strainer.


As far as the temp.....
This past weekend I was "up a creek" where the water is warmer than the main stem of the river. I did notice that my water and oil temps were higher. My water temp was up to about 160* according to Smartcraft.

The water temps on both of my 525's stay right at or just below 150 and really don't fluctuate a lot.

I just replaced the original CMI headers with the new CMI's and installed water pressure gauges at the same time. I hooked the gauges up to the same place that the oil temp sensor is on the oil cooler and I am concerned with the readings that I am getting. At idle they are both about 8 psi and that is also what the scan tool says as well. When I get up round 4000 rpms I am reading 40+ psi on both engines. I did not have gauges before so I am not sure if this is correct or not. I also noticed that the restrictors on my tailpipes are .389 for the starboard side and .406 for the port side of the engine and the newer versions have .406 for both sides. The new headers do not have the up/bypass tube to the tailpipe so that inlet is plugged. I have been hesitant to take the boat much above 4000 rpms until I can determine if there is a problem or not.

Any ideas?

My 525's are also around the 150 degree mark. I have one at 150 and the other runs 140 consistently.