8-71 TI Temp

[scottinsydney]

I ran the motors up to 1450 rpm which is the absolute maximum I will ever go for the next 20 years due speed restrictions. Used my IR gun on the thermostat housings and recorded about 167 degrees for both engines. Why can I not necessarily use replacement 180 degree thermostats? My thoughts are they will solve the issue of running cool engines. Nobody will drive the boat except myself. The old thermostats can be stored for a future owner.

[racclarkson@gmail.com]

I ran the motors up to 1450 rpm which is the absolute maximum I will ever go for the next 20 years due speed restrictions. Used my IR gun on the thermostat housings and recorded about 167 degrees for both engines. Why can I not necessarily use replacement 180 degree thermostats? My thoughts are they will solve the issue of running cool engines. Nobody will drive the boat except myself. The old thermostats can be stored for a future owner.

No reason. Do it.

[SKYCHENEY]

You state that you normally run at 900rpms. The 180's will make absolutely no difference in temps at that rpm because they will not even start to open same as the 170's or even 160's. Do as you wish but you will likely see no change. To get the temps up, you need to run them at higher rpms.

[Briankinley2004]

Put one in forward and one in reverse and advance throttles to 1800. I bet you come up to temp and dont violate the speed restrictions. I personally agree with Robert on this

[scottinsydney]

The farmers in Australia refer to spinning a car around in a paddock as "Circle Work!" Perhaps I could try this on my boat in front of the Sydney Opera House. I'd be sure to be breath tested by the water police.

Anyway, the issue at hand is IF the engines will generate enough heat at 900RPM to increase the coolant temperature to around 180 degrees?

If anyone has a parts book, the blue tag on the engine says SN 12VA077581 and the thermostat is #76.

Cheers.

[Photolomy]

What is the full range of RPM's for 8V71TI engines in a 53' boat, and what should the temp be throughout?

[kelpy]

167 deg. at 1450 RPM or so sounds about right.

Changing thermostats to increase the operating temperatures at low load/RPM is as fruitless as changing injector size to get better fuel economy. Detroit Diesels just don't work that way.

[Capt Chad]

Well, I pulled the heat exchanger because it was the only thing I haven't had apart. It looked like it was brand new... I pit it all back together. I lot it to check for leaks. I have water spewing out of the week holes in the inner cap on the outgoing side of the cooler. I know something happened to one of the o rings. Anybody ever had this happen?

[Scarlett]

Wait a minute Scott, I seem to remember someone else driving your boat a few weeks ago, and by the way enjoying it a lot. John

[KPTIM]

On the thick plate / spacer on the out going side of the heat exchanger.
That plate has to go on facing the correct direction.
If you put it on reverse / backwards water will come out of those small weep holes.
It is very easy to install it wrong.

The other cause for this is if you use the wrong after market O-rings and also can happen if you do not replace the crush ring that goes between the two O-rings.