Running Hot

[woobs]

thanx for the explaination so it is the thermal device that doesn't get heated up if you put it in backwards because the heat source the coolant is on the other side so it never really lets it open?

Correct. If it gets hot enough when in backwards... you no longer have to worry about the t-stat as everything will be cooked/melted

I added a video link to previous post.

[mattyboy]

ok I know the spring goes into the intake with an old holman moody housing the tstat might not seat correctly into the recess cause it has rusted away over time so the tstat can move or dislodge that's why I didn't add one to this new motor

an example not an HM housing

[woobs]

The recess for the t-stat housing may be in the manifold or on the housing. Once in correctly it will never move. The trick is to make sure it is in the right place when you torque it down so you don't crack the housing.

Damn Fords are vertical... most GM & Chrysler are horizontal.

[mattyboy]

Yeah Gravity is your friend with a Chevy with a Ford not so much

[champ]

Well, my weekend sucked. Bought 4 thermostat gaskets just in case. Removed the thermostat housing, turned out that the bypass was clogged with old gunk. Yay, I thought as it cooled the manifolds back down. Kept the 180 degree thermostat in it and went for a cruise. Ran great.

Second run went perfect, except I forgot to latch the hatch. It blew off but I managed to save it before it sunk. Broke the bolts holding it on, embarrassed for my friends to see I snuck back onto the pier and fixed it real quick.

Broke the tilt jack too, but so what? I could take my girlfriend for a cruise. All was good and she was smiling then it got hot again. Brought it back in, removed thermostat housing, clogged bypass again with new scale from motor.

So, anyway this is where I'm at. I guess its time for another solution.

Thanks for all the input and suggestions.

[mattyboy]

I would pull the block plugs and riser plugs and push a wire hanger around in them then pull the riser hoses and run the water thru a hose with the motor not running remember on the hose don't go full pressure see if you get gunk out then when the water is clear thru the block drains put them back in then run water until it is clear out of the tstat housing reconnect the riser hoses and run water thru the risers until it is clear. another option would be running it on a pump with like a prestone auto coolant with rust additives recapturing the exhaust coolant and repumping it in like winterizing it that may break up the gunk but there is always a chance you send the gunk further down the line and block the smaller water passages

[Lenny]

...another option would be to pull it, tear it down, have it boiled, line bored, honed and get happy with what you have and not worry anymore...

I wouldn't want your issues on the ocean.

[champ]

Still trying to understand why I would run it without a thermostat. But even with a 160 thermostat, temps do not go much over 120 with one. That's on dry land or in the creek just idling around. Only when getting on it does the the temp go up and my guess is when the bypass got clogged did it start to get hot. I really do think there is a lot of water pressure with the two new pumps helping to hold the thermostat closed.

Gonna try Matty's advice first. And, maybe without a thermostat this time. Seems to have lots of flow through exhaust running off a garden hose. The video I was trying to upload showing water flow out the exhaust was to large to post.

Thanks for your suggestion Lenny, here's a pic showing why I don't want to pull the motor, at least this time of year.

20160617_202145[1].jpg

[mattyboy]

no tstat to eliminate one possible problem it will be a process of elimination if the bypass is getting plugged flow thru the tstat can too under load

on the hose it will always run cold and Flow will always look good the hose is doing the pumps work out in a warmer body of water it is all the pump(s)

the crud look black or red?

It may pay to drain the block and pull the the tstat and put the drains in let it soak in auto antifreeze for a few days my lil irish Nana would say vinegar will eat that rust away but it may also eat seals and gaskets so an auto antifreeze with rust additives may help

cooling issues can be hard what does flow look like in the water ? when was the last time the risers were pulled and inspected any scorching of the paint or surface of the risers?

[Pat McPherson]

I'm not a ford guys so excuse my ignorance. I had an engine, Chevy 502, with lots of scale in the block clogging chit up. I didn't want to pull it because it was mid season. I pulled a freeze plug on each side and ran water through via the thermo housing. I worked a coat hanger around in the water passages while the water was flowing. It filled my bilged with rust and gunk. replaced the freeze plug and cross my fingers. The engine ran great for 2 more seasons before failing 75% through a 3rd...

[CHACHI]

Pat, salt water?

Ken

[Pat McPherson]

Pat, salt water?

Ken

Ken, the engine I had was originally in a 1996 29' Fountain a friend of mine had purchased with about 300hours. He ran the boat for another 250 or so and it lost oil pressure. He sold it to me for $500 with the agreement I'd help him build and install a higher output engine. We build a 525SC clone that made about 575 for his boat. I rebuilt the 502MPI totally stock and ran it in 2 different boats for another 7+ years and 500+ hours before it got sick again and I sold the boat with the engine as is.

[gcarter]

Ya know, a lot of these replies are good reasons to include
closed cooling on your next new engine.

[champ]

Just to update, boat is running good. Clogged bypass in tstat housing has not come back. Am using a 160 degree thermostat, but motor has not even gotten to 140 degrees yet even after hard runs.
Is this a safe temp to run at?

[Just Say N20]

Engines run cleaner and more efficiently at the 160+ temps. I don't know that you will "hurt" the engine running cooler, it just won't run as clean.