Engine ran cooler after alternator conversion?!

[glastron86]

I finished the alternator conversion on my Mercruiser 170, took the Glastron out today, and the boat ran great! One thing that I wasn't expecting was the difference in how cool the motor was running, according to the dash guage. It does sound possible for it to run a little cooler, since power isn't being generated by the old stator to be run through the water cooled voltage regulator anymore. The fresh water lake that I typically go boating in was basically the same temperature as before, so the conversion is the only thing that has changed. Does this make sense to everyone else? Please let me know! And I definitely want to thank everyone who helped direct me to get through the alternator conversion!

 

[whywhyzed]

Re: Engine ran cooler after alternator conversion?!

Hard to believe the regulator would generate that much heat. The thermostat should control the temp. regardless. If you are picking up less heat now due to the swap, your thermostat should close a tiny bit and keep the temp the same.

What I think is possibly happening, is that your new alt. is regulated at a bit lower voltage. You have a temp. gauge that doesn't have it's own V regulator (although most do), so it reads a bit lower with the lower supply Voltage.