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Running a 57 without a T stat

S

srdancer90

Regular Contributor
I have been told from several

I have been told from several people that I can run my 5.7 with out a T stat. Other merc techs have said that the engine will over heat if tit is run with out a T stat. My question is can you run a 5.7 alpha 1 gen 1 at all ranges with out a t stat and not have the rear cylinders be damaged?
 
"I have repeated my response v

"I have repeated my response verbatim from an earlier topic that is quite similar:

"You should not run without a T'stat. The T'stat assures that the engine will get warm enough to vaporize most of the water condensation and contaminants from the oil. It also acts as a restriction to the free flow of cold water through the block (with a RWC engine), and reduces cold spots . Running without a T'stat has no advantage.

If you are having trouble cooling with a T'stat installed (one that is opening properly), you have a cooling water supply problem, or a blockage somewhere. Running without a T'stat will not fix it."

Rod"
 
"[b]"If you are having tro

""If you are having trouble cooling with a T'stat installed (one that is opening properly), you have a cooling water supply problem, or a blockage somewhere. Running without a T'stat will not fix it."

Ayuh,... Exactly...... Fix it...."
 
"Un-known to me, I ran my 5.7

"Un-known to me, I ran my 5.7 without a stat last year. It ran very cold, used loads of fuel and hesitated every time I opened it up. It now has a stat in it and runs lovely."
 
"The T stat question has been

"The T stat question has been answered. The issue I face is: the water pump is changed every season upper, and lower. the circ pump was changed 2 years ago. the risers and manifolds were changed two (2) years ago. I located a kink in the hose wihin the bell housing and that was just changed this spring. A week ago the engines ( I have t/5.7) ran about 150 ( 143 t - stat in each) upon increasing throttle on the port engine the temp raised to 160 and was creeping up. I lowered the rpm on both engines and the temp droped down to 145-150. Is it a possibility that if one engine is working harder than the other that the temp on that engine will be hotter than the other? I must say that I am always in a muddy enviorment at my dock space, at low tide I kick up billowing amounts of mud. When I raised the question to a merc tech about mud clogging the system, he stated that the mud would be washed out of the engine as I entered cleaner water.The question remains why would only one engine exhibit these types of symptoms and the other not, they are both in the eame enviorment at the dock. I did notice that when I changed the temp sending unit in the hotter engine there was mud caked all around the sender. The oil cooler on both engines are flow thru types, I checked the hotter engine to see if mud was present there, noneIs the hose from the transom assembly to the oil coolwer under vacume, that is can it collapse and cause a restriction? It has not been changed.Looking for some other suggestions."
 
"Are you sure the indications

"Are you sure the indications you are looking at are accurate? Could have a sending unit on the fritz or corroded wire terminal somewhere giving you fits.

First thing I would do is confirm your indications.
Get a hand held ifra-red thermometer (<$50 at sears) and check the the sending unit housing temperatures against what the gages are showing. Then check a few other spots around the suspect engine vs. the 'good' engine.

Almost impossible the balance the engines perfectly, but that doesn't expain what you're seeing. The normal running temps should be pretty darn close.

One other thought... are you sure both the t-stats are the same? For raw water cooled you should have somthing in the neighborhood of 165°F."
 
"when I changed the temp s

"when I changed the temp sending unit in the hotter engine there was mud caked all around the sender"

Did you look at the shutters on that engine? Sounds like a flow restriction. Mud won't completely wash out of a block no more than rust sludge will. You proved it above.

Start w/shutters and then pull the risers since mud may be blocking the gasket openings.
 
"Joe - Go run that boat and le

"Joe - Go run that boat and let me know when it gets past 185. You're not going to hurt anything at those temps. I would start worrying if it creaps up past 190ish.

Graham's rig used a ton of fuel because the EFI was staying in rich cold start mode and loading the plugs, btw."
 
Can you force the mud out of t

Can you force the mud out of the risers using a garden hose attached to the bottom of the manifold
 
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