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Interpreting Some Operating Temperature Measurements

knuckle47

knuckle47

Advanced Contributor
I have been trying to solve th

I have been trying to solve this steam thing with my FWC engines. I had measured my engine temps this weekend to try and see what is really going on. Ran on and off all day so after about 8 hours on the way in here is what I get at about 3100 - 3200 rpm.

Exhaust manifolds 197
Thermostat housing 188
U cooler 114
Heat exchanger 196
Exhaust elbow 134
Water adapter 277

THAT water adapter one bothers me. These adapters are between the exhaust manifold and exhaust elbows and have the stainless block off plate just before the elbow. I have all new parts in the coolibg system plumbing and these water adapters do have a yellowing hot spot on the outside edge. Anyone have a clue here? I have not yet suspected the engine antifreeze water pump but?
Actual gauge temp on the dash shows a rock steady 160 at times 140 to 150 but never over the 160 mark.....
 
Odd that your therm-housing is

Odd that your therm-housing is 188 but your gauge is 160. I myself am chasing a steam/temp. gremlin.My gauge reads 190 but my therm housing reads 176. Steam wisps away at 4 feet. My manifolds are 180 at 3200 and risers are 135.that 277 may be your culprit. Where is that on the engine?
 
"Ted,

I have the same 4 fee

"Ted,

I have the same 4 feet but depending on humidity, it could be 12 feet or better, I agree that the 277 in a water presence could be the problem. The water adapters are located between the exhaust manifolds and the elbows. They are about 1 1/2" wide they are clear through to the exhaust manifold on each side but have a block off plate where the exhaust elbows mount. It looks like a plain old spacer between the two parts with a hose fitting on the top. Then from the elbow, it goes to the 4" wet hose for about 12" then to the muffler and from the muffler, another wet hose to the transom ports. I just realized by what you had said that the temp sender is right there at the thermostat housing and should reflect the same information......hmmm!

I did see an older Silverton today running with about 3-4 feet of steam. BUT that dose'nt mean its right...yet."
 
"Here is a picture of it<[img]

"Here is a picture of it
217490.jpg
Crusader water adapter
 
"AL:

what do you have in th

"AL:

what do you have in that pipe fitting on your adapter?

It looks like the older style rear outlet stuff I took off mine years ago. Seem to remember that being in the Freshwater side of the cooling system but am not certain. If nobody else chimes in, I'd check the owner's book for some pictures - shouln't be too hard to figure out.

These things are 'wet' exhaust systems - they need water flowing thru each piece. With the 270+ temp and a yellow hot spot, I'd think there isn't any/enough water in your 'adapters'"
 
"Al, I seem to remember that I

"Al, I seem to remember that I changed my gaskets about 3 years ago and the gasket covered several of these openings. I will check the spare gasket when I get to the boat this weekend and let you know.

Chuck"
 
"Chuck....IF .... IF I am n

"Chuck....IF .... IF I am not mistaken, I may rememeber the same thing here. I would hate to remove the assembly to check that out BUT MAN...I could almost bet you are right.

Mark, As for a pipe fitting, it is a 90 degree hose fitting for a 1 " heater type hose that runs from the adapter to ???? MAYBE the heat exchanger? I can't remember that unless I am at the boat or have a picture here somewhere....I am gonna go check....."
 
"<[img]"http://www.marineengin

"
217549.jpg
Engine"">

I made a mistake...This picture shows a 1.25 wet exhaust hose carrying antifreeze coolant to the heat exchanger from the water adapters located JUST BEHIND the exhaust elbows...

these engines are mounted backwards using V-drives...That U-cooler is actually facing the transom

Suggestions?

Now I am lost !"
 
"For what it's worth, I ha

"For what it's worth, I have a pair of 270hp Crusaders, 1989 year model,FWC in a 30' Luhrs. Replaced the riser and elbow on the port engine outboard side. The riser and elbow had clogged up and stopped flowing water. Previous owner never changed it so it melted the exhaust hose and muffler. Bought new risers and elbows. I think mine are a little newer than yours because it doesn't use the spacer. The raw water goes into a fitting on the riser. But the interesting thing is with the gaskets. The block off plate has a gasket on both sides, doesn't matter if is a 3 hole or one hole since all it does is block the manifold FW. BUT between the riser and the elbow you have to use a one hole gasket with the hole on the top. Didn't quiet seem right since, in my limited reasoning anyway, that you would want the max water flow. This is what the instructions said that came with the risers. Bought the Crusader manual and it said the same thing. The purpose is to fill the riser with water so it runs out the top. No sure if this has anything to do with you problem but a little extra input doesn't hurt!!"
 
"Thanks Al,

The side of the

"Thanks Al,

The side of the adapter that fits against the exhaust manifold is only a gasket so IN THEORY, it should fill with something ? Funny part is...I could run all day and have....it isn't that she overheats...its just THAT STEAM THING ! I am really trying to understand IF I HAVE IT SET RIGHT or did something get crossed from the rebuilds"
 
"Al:

the 277 on the adapter

"Al:

the 277 on the adapter is an anomoly. With your pictures, we've got a better understanding of your setup. Best guess is maybe the wrong gaskets used in the install.

The best cartoon I found is here:
http://marineengineparts.com/shopsite_sc/store/html/media/PDF_FILES/crusadergask etchart.pdf.

You should be able to check which gasket is in by the "tabs" along the outer circumference of each gasket. I'd think you've got a 1 slot where you should have had a three slot. If the tabs are gone, I'd check each of the four adapters - If only one is 'hot', that's the bad guy.

You used to be able to get temperature crayons at the welding supply store. I'd get one that melts under 200 and one that melts over 250. use these to probe the exterior of the adapter, where each water slot is. If three are hot and one is cold...enough said. (if the gaskets were installed with the "tabs up" and the top is cool but the sides & bottom are hot, water is only flowing thru one channel.)

You should also verify the temp at the hose going back to the tank and on both sides. If they are ~195, then your 'problem' is definitely isolated to the adapter.

One Other "maybe" could be a piece of flashing restricting or blocking one (or more) of those slots - a real possiblity with "new" parts."
 
WOW MARK !!!!

You have a ha

WOW MARK !!!!

You have a handle on this as IF you had watched the install....I am 99% sure you are correct as my TABS are up and I do believe the gasket has 1 slotted hole and obviously this restriction is the likely cause....I will be in there tomorrow if I can get there and check this out....THANKS !!
 
"I have twin 350 crusaders 196

"I have twin 350 crusaders 1966, raw water cooled. the temp gauge doesnt move off of 125 degrees. Heat scaned as follows.

At the head where the manifold meets 148-150
At the manifold 120
at the elbow 115
at the thermostate housing 123 degrees.
I have light steam 2ft aprox."
 
"<font color=""0000ff"">I tota

"<font color=""0000ff"">I totally agree with "diver dave". Thermostat is either missing or stuck open. A cold engine is not good (oil too thick, wastes gas).</font>140 degrees is used in a raw water cooled engine vs 160 deg. for fresh water cooled."
 
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