# Minutes to Open T-Stat (3.3L engines)

[HMBJack]

Quick Question:

Without guessing, on a F200/225/250 3.3L Four Stroke, does anyone really know how many minutes it typically takes for the Thermostats to open when flushing at idle on Muffs?

Assume flushing at 800 RPM's. Thank you.

[fairdeal]

what is the starting temperature of the engine block?

what is the temperature of the water being supplied to the muffs?

[99yam40]

I am sure it depends on how cold the motor and water flowing into it is

[boscoe99]

What is the flow rate of the water?

Does the thermostat open on the low side of its range or on the high side of its range?

Do all thermostats go from closed to fully open at the same rate given the same temperature of water?

What is the sound of one hand clapping?

[HMBJack]

Engine is cold. Water temp from garden hose is 50-55 degrees.

Just trying to determine how long a flush should go on the muffs. I was thinking 5 minutes but would like to know from others who know better.

[boscoe99]

Here is what the owner's manual says.



I personally flush my motors for at least 10 minutes. Water is cheap. Engines are not.

[fairdeal]

this was touched on recently in another thread, where I wrote:

well, there's the question of if - or at least when -

the thermostats do actually open while running on muffs.

Here's the specs for the F225:



Now, I don't run much on muffs, so I have no data there.

But actually using the engine to move the boat:

When I leave my dock, I travel 1/2 mile at a fast idle before I get to open water. Takes about 15 minutes.

And from a "cold start" - at the end of that trip, the block temperature is typically only ~145*F

Now, that's talking about an engine at a fast idle under (some) load

with an air temp (engine block starting temp) of ~80 F

and a water temp of ~80 F

[HMBJack]

Thank you.

I'll go 10 minutes... Appreciate the responses.

[boscoe99]

Do a fairdeal test.

With the motor cold remove the water flow hose at the bottom. Install the flush muffs. Turn the garden hose faucet to wide open. Start the motor. Look at your watch and note the time. Observe the bottom of the tube to see when copious amounts of water begin to flow out. Serious water flow should indicate that the thermostat has opened.

[pstephens46]

Ran my F150 on muffs a couple weeks ago for at least 10 minutes. I had the YDS hooked up also. Motor never made it to 125 degrees according to YDS. Probably 65 degree tapwater. I finished what I was doing and shut it down prior to thermostats opening.

[cpostis]

Quick Question:

Without guessing, on a F200/225/250 3.3L Four Stroke, does anyone really know how many minutes it typically takes for the Thermostats to open when flushing at idle on Muffs?

Assume flushing at 800 RPM's. Thank you.

Well, My boat is kept on a trailer. Since I disassembled my motor to remove excess deposits in the cooling passages, I now always use a tank and muffs to flush. I run until the water in the tank reaches 95 degrees and am assured the t-stats open, then attach muffs and run another couple of minutes. In my opinion the warmer water temperature helps dissolve deposits, plus you also flush deposits from around the prop bearing housing. I do put her a gear at idle.
But, I am also know as a fanatic.

Click on the image to see the video.

[IMG]Flushin' by Charles Postis, on Flickr[/IMG]

[pstephens46]

How long to fill that tank to flush?

[cpostis]

How long to fill that tank to flush?

About five minutes or less. Got the 100 gallon tank from Tractor Supply for $65 on sale. Just in case you're wondering, My water rate is $2.20 per thousand gallons, I'm on a septic tank/drain field so no sanitary sewer charge.

[pstephens46]

5 minutes! Bet you could drain it very quickly too if you popped it into gear and revved a few times.

[fairdeal]

Got the 100 gallon tank from Tractor Supply

Nice!
I've been admiring them for some time.

But its 412 miles round trip to my nearest Tractor Supply....