still running hot

[joseph m. hahnl]

well i finaly got my trailer and got rid of the loaner i had after rebuilding fenders bunks and lights i was able to go down to the lake where rooster tail "my minx" patiently waited over night for me. was actually 6:00 pm be fore i could even get there. i started her out and went down the river to the lake. 6mph for about a 1/2 mile. the temp went up to 190 . i gave her more rpm to circulate the coolant, temp dropped right down to 150. the thermostate is a 160 so i would give it to 170 before i start to worry. we went around a few times stopped for a barbeque. and then went around a few more times. between 2500 3000 rpm i came of plane idled back and went again she started getting hot again so i shut her off to cool down and watch some fire works. i haven't got the mufflers yet they should be here wednesday. well some putz called the marine patrol "trouble makers on water" but be cause she was off, anchored with the light. there wasn't to much he could do so he left me alone and went to herrass some chump out in a paddle boat with out any lighting. probably the guy who called trouble makers son . marine weenie left and i waited about an hour and started her up and went down sream to the launch. ran about 150 to 160 just over idle. i think i would rather run it with out a thermostat .

"any one have any objections to this or kind words of enthusiasm"

joe

[synack]

I think it would be pretty unusual for an engine with a 160 degree thermostat to run at 150 degrees.

Having just swapped out a faulty thermostat in my boat with a brand new 160 degree one, I normally idle at about 165 to 170 and reach temps up to 180-185 under WOT.

Your operating range sounds fine. However, the 150 degree drop is odd.

[MOP]

Are you running a full or half system? I called Gil about running a full over a half system the tech told me that running a full system taxes the cooler by about 30% more, He said my headers with flushing will last 10-12 years so on his advice I went with a half system. Something to note about closed cooling, when you throttle back fairly quick after running at cruise or higher the gauge will always go up quite a bit can go close to 200, they call this false over heat! What happens is the circulation of the block water gets very slow allowing the hotter water to rise, applying a little throttle gets it moving and the gauge goes down. If you throttle down slowly it does not happen, several times a year a customer will come in all upset saying the boat is over heating and we have to go for a run and show them that this is a normal malady of closed cooling. This does not explain the running over heat you have but at least you will know that it is a normal thing. If you have real good water flow out of the exhaust I would try another Tstat, once in a blue moon you can get one that does odd things.

Phil

[gcarter]

I must say I've been very pleased with the electric circ pump I've been running. At idle, it runs @ 170* w/a 190* 'stat. At all other speeds it runs at about 195*. It NEVER varies. I think a lot has to do with the constant 55 GPM of the electric pump. BTW, it's a full system.

[joseph m. hahnl]

Are you running a full or half system? I called Gil about running a full over a half system the tech told me that running a full system taxes the cooler by about 30% more, He said my headers with flushing will last 10-12 years so on his advice I went with a half system. Something to note about closed cooling, when you throttle back fairly quick after running at cruise or higher the gauge will always go up quite a bit can go close to 200, they call this false over heat! What happens is the circulation of the block water gets very slow allowing the hotter water to rise, applying a little throttle gets it moving and the gauge goes down. If you throttle down slowly it does not happen, several times a year a customer will come in all upset saying the boat is over heating and we have to go for a run and show them that this is a normal malady of closed cooling. This does not explain the running over heat you have but at least you will know that it is a normal thing. If you have real good water flow out of the exhaust I would try another Tstat, once in a blue moon you can get one that does odd things.

Phil



Phil: it's a full system. runs thru the manifolds too. maybe i'm just panicing
it does blerble out into the over flow bottle which is probably normal." i just don't want to blow another hose". i can tell that the thermostat is open
it just doesn't seem like there's a lot of pressure or flow thru the top hose.
the high temp LED didn't come on. so it didn't actually overheat. but the high temps seem to thin the oil and the oil pressure gage goes down to 25.

[gold-n-rod]

but the high temps seem to thin the oil and the oil pressure gage goes down to 25.

I don't think 25 psi is bad for a hot idle (even 20, for that matter). Is the 25 psi that you see at idle in neutral or in gear under power at idle?

Isn't an OK oil pressure range for a marine engine 20-60 psi, depending on RPM?

PS: What oil weight are you running?

[joseph m. hahnl]

I don't think 25 psi is bad for a hot idle (even 20, for that matter). Is the 25 psi that you see at idle in neutral or in gear under power at idle?

Isn't an OK oil pressure range for a marine engine 20-60 psi, depending on RPM?

PS: What oil weight are you running?

20w 50 and it's at under power idle
joe

[gold-n-rod]

20w 50 and it's at under power idle
joe

Well, that doesn't sound like a problem to me. Maybe try a straight weight 40 and see if that makes a difference.

[MOP]

Is the low oil pressure running or idle? Running at 20 would bother me at idle OK. I see a lot at 20 idle and 35-40 running on stock engines. Maybe you should give some thought to adding an oil cooler.

[joseph m. hahnl]

Is the low oil pressure running or idle? Running at 20 would bother me at idle OK. I see a lot at 20 idle and 35-40 running on stock engines. Maybe you should give some thought to adding an oil cooler.

20 at idle 35 under power. so it would seem as if everything is normal.
i will run with it i just wanted affirmation.

thanks
joe