Pardon me Don S...

[magster65]

Re: Pardon me Don S...

its called heat soak
its also not helped by the stock alpha seawater pump.
while not every boat does it its rather common to see on freshwater cooled boats.
Diesels will do it as well and its why they reccomend an idle period to stabilize egine temps before shut down.
you will find a belt driven seawater pump and a through hull pick up will cure most of it, however as long as you keep the stock alpha setup in top notch shape it will work with no worries.
that setup has a lot of heat built up during the 3500 RPM plus range then is suddenly dropped to idle.
at idle not only does the engine circ pump slow down but so does the pressure from the seawater pump. takes a min or two for the liquid to liquid HE setup to catch back up.
most cars will do the same, shut off the engine and imediatly turn the key back on and you will see the temp climb with the engine off for a few minutes.
190* is still within the operational limits of the 5.7.

Yeah, I'm familiar with 'heat soak' but this isn't an alpha, it has the bravo set-up and I put a new impeller in it to kinda' rule that out... and you're right, my other boat has the alpha setup with no problems.
I'm gonna' borrow an infra-red temp sensor and see if it's a 'hot spot' at the sensor or if the engine really is warming up... but I kinda' doubt it is.
It doesn't feel hot and the temp guage goes up and then back down pretty quick... I don't if it's actually possible for an engine to change temperature that rapidly?

 

[magster65]

Re: Pardon me Don S...

I was surprised they have you mount the sensors out on a "T" like that. I would have a hard time trusting what they were reading was accurate.

Yeah... I might be making my own t-stat housing... which I don't mind.
If it works I'll send one to Dave at San Juan manufacturing to copy for his kits.

 

[magster65]

Re: Pardon me Don S...

OK, this is it... the follow up.
I made the t-stat housing out of some 1 1/4" copper fittings and a brass base then drilled a couple holes and put 2 IP fittings for the sensors and silver-sautered the whole works together. I also took all the fittings off that the kit came with and lowered the hoses that run to the hot water tank. It works great. There's no temperature increase when I slow down... even from full throttle to idle. It also reads 162 again, the same temperature it ran as a raw water cooled engine.
I'll call this 'mission complete'... finally!

 

[Robj]

Re: Pardon me Don S...

Glad to hear it all worked out for you.

Have a great day,

Rob