Originally Posted by Ex-Calif
Here's a new maybe dumb question - Is the fresh water
Actually, that had occured to me, but I wasn't sure at all how to test it.
Last week, I spoke to a mechanic
and they recommended I get a handheld infrared thermometer gun, the ones you guy at an auto parts
store and use it to measure temp on certain areas of the engine
To see if the fresh water is circulating they said to measure the temp on the block before and after the thermostat opens (stat starts to opens at 164*F and is fully open at 189*F). Looking back at my notes from the other day when we ran the boat, I see that I only have ONE such temp measurement
Argh! That day, I was measuring temps over time at the area where the temp sender is and comparing it to the gauge reading, then measuring temp of raw water
into and out of heat exchanger
, etc...we were raising and lowering sails
, checking various things on the engine
, etc. and it looks like I only measured block temp once...idiot!
So it might not be useful info. Too bad I didn't do it several times, over time.
Anyway --here's what I have: when the area on the cylinder head
around temp sender was 180*F (so, presumably the area where the hot coolant
is inside the cylinder head
is a bit hotter since the temp sender is in the liquid), the block was 194*F. These measurements were done after the engine had been running for an hour more or less. So, the block appeared to be hotter after the thermostat had been open for at least a while.
I guess this might --possibly
-- suggest that that freshwater is not circulating, or not circulating enough --according to the mechanic
I had spoken to (the one who recommended measuring temperatures). But I'm skeptical about trusting this temp measurement since I was dumb enough to only do it once! Argh...And, frankly, those handheld thermometer guns
read a few degrees differently depending on how closely you hold them to the surface you're measuring...and the boat is moving, your arm and hand moves a little bit, etc. Not sure how accurate the measurements can be.
All this to say: maybe fresh water isn't circulating well, but I don't know how else to check this! (I was going to go through the raw water
side thoroughly first before looking at the fresh water side --I pulled my raw water pump
yesterday to have it tested by a pump shop-- but I'd be interested to know ways to check fresh water circulation.)
Sorry for the long-winded post...mirrors my confusion over this whole issue!
But, yeah, fresh water circulation...any ideas on testing it?