Engine water temps?

[zimm17]

I have a whipple blown, EFI 454 magnum. I have closed loop cooling and had a 180 degree thermostat and the engine ran a steady 190-200 deg. I pulled the thermostat out and idled it for 15 minutes in the driveway on the garden hose- it never even got above 100 to make the needle move. Oil temp didn't move and it starts at 140. Should I take it for a run and see what it does WOT? Or should I put in a 140 deg thermostat so it doesn't run too cold? What is too cold for a 600HP blown engine?

[BUIZILLA]

with closed cooling I would use a 160*

[yeller]

Well, I'm not an engine guru, but I'd take it for a run. I never ran a thermostat in my 350 16C....and that was with fresh water cooling. I did put one in once but lost a couple mph so I tossed it. Some people told me I'd cause cracking of the heads due to the cold inrush of water if I fired the boat up if the engine was hot. I never saw any problems.
I remember reading an article a couple years back written by either Teague or Tocket (can't remember which one) and he said he never saw an engine damaged by running too cold.....only too hot.

[gcarter]

I ran 160* in my FWC SBC Minx. It would run 140* until you got on it then it would creep to about 165*.

[tom freeman]

do you need a thomostat?
what is the right temp for running like 60% throttle

[gcarter]

I don't know much about Mercruiser EFI, but I would assume you need to keep the engine a minimum temp for it to operate correctly.

[slamdry]

i run a 160 in mine, you do want some heat in the water so you dont get expansion and contraction.

[mrfixxall]

i run a restrictor plate in mine,,,15 years in the first engine and 6 in the second engine and never had a issue:yes:

[Cuda]

I don't run a t stat in any of my engines, but they aren't EFI's. I'm pretty sure it make a bigger difference on an EFI engine. I think the EFI takes the engine water temp into account, ie, if the water is cool, it will richen the air/fuel mixture. Now this is only a guess on my part, I've never owned a marine EFI engine.

[Barry Eller]

I don't run a t stat in any of my engines, but they aren't EFI's. I'm pretty sure it make a bigger difference on an EFI engine. I think the EFI takes the engine water temp into account, ie, if the water is cool, it will richen the air/fuel mixture. Now this is only a guess on my part, I've never owned a marine EFI engine.
I have a crossover system and a carburetor. I do have a thermostat, but it has six holes (1/16") drilled in it. In Florida the water temps are warmer than up north, we may be able to get away without t-stats, but the guys running in cold water probably need them. EFI's need them for sure.

[kd5cue]

I have a crossover system and a carburetor. I do have a thermostat, but it has six holes (1/16") drilled in it. In Florida the water temps are warmer than up north, we may be able to get away without t-stats, but the guys running in cold water probably need them. EFI's need them for sure.nice looking yellow motor

[BUIZILLA]

I don't understand why you wouldn't want a CORRECT thermostat for the application??

also, and I apologize if this has been covered before, but does ANYONE run an Alpha setup with a crossover??

[gcarter]

I don't understand why you wouldn't want a CORRECT thermostat for the application??
also, and I apologize if this has been covered before, but does ANYONE run an Alpha setup with a crossover??
When I bought the Minx, it was set up that way. But since the outdrive driven pump is so small, that may have been part of the reason the engine had failed. But if someone were to install a transom mounted pickup and eliminate that small pump and add a seawater pump, it should fix any issues.
I later used the crossover in th FWC system w/the Meziere remote mounted pump.

BTW, would you PLEASE smash that gnat? I can't get to it from here.

[BigGrizzly]

Wipple says no stat, my sons doesn't have one and his runs rich. Garry Grimes disagrees with wipple. My engine is procharged and we run a 169 t-stat. Mrfixall runs a restricter so in effect he has a t-stat. Too cold you have you have uneven temp problems in a BBC. With out closed cooling systems we always have to put restricters ib the blocks to prevent thermo shock. My engine runs within 50 degrees between cylinders with the closed system and no restrictors. I would run a t-stat, no higher than 160 just to avoid the possible detonation with a unforeseen situation. The engine will also make more power and have better economy.

[tom freeman]

i just got back from an outing, and i have a weird problem. my 290a outdrive when at 2 degrees tilt to negative 4 degrees well the engine cools fine runs at 160. i have a 142 degree thermostat. all my pumps on the engine are new. when i tilt the engine to like 7 to 9 degrees the engine gets hot right away, and when i slow down or tilt down it cools down right away. any one have any thoughts.:bonk:

[zimm17]

I just ordered a 140 thermostat, thanks to all for the advice.

[BigGrizzly]

Tom you have a 290 out drive. On the lower unit their is a pre-bent hose that may kink and cut off the water supply. The other issue is at a tilt the pickups on the lower unit may not pull enough water in. I have a transom pick up on mine and it is a better idea. Ypu can get them at Stainless Marine. Now iif you do hav a transom pick up you have it mounted incorrectly.

[tom freeman]

so Big.. my best interest in your opinion is to go to stainless marine get a transom pick up and install it. is there any specific model and r there any other requirements. do my 2 pumps stay the same.

my mechanic louis said it could be the sender... is that possible?

I will say this i would punch it for say 45 seconds at 7+ degrees tilt and the trim is bow down to calm the chine to chine. it shoots up to like 210 degrees, so i back her down and run back to the engine, it will have cooled that quickly... but i can touch the risers and the valve covers. there is no steam either.

now having said that do YOU think that the transom mount is the long term way to go especially knowing i am building the new engine also.

[gcarter]

I agree w/Griz. A well installed transom mounted pickup solves all types of problems...insuficient water supply, picking up sand and weeds, failing hoses, etc.
Take a look at an 18 w/a Volvo outdrive that I did recently...particularly page two and three;
http://www.donzi.net/forums/showthread.php?t=49388

[tom freeman]

I agree w/Griz. A well installed transom mounted pickup solves all types of problems...insuficient water supply, picking up sand and weeds, failing hoses, etc.
Take a look at an 18 w/a Volvo outdrive that I did recently...particularly page two and three;
http://www.donzi.net/forums/showthread.php?t=49388

now i have read some other threads...
some suggest, timing, a kink in the hose that runs from the drive to the transom, bad sendor for temp... any thoughts

[gcarter]

I would certainly try to eliminate the other areas you mentioned, after all...it's easy to do. But if it is a hose, maybe it's just tired and needs to be replaced.
I do think though that a lot of problems people have w/their outdrives could be solved w/a pickup.

[tom freeman]

i had my mechanic order the whole deal today,

thanks to all for the help,

it was not the timing, i had alot of burns on my old prop... so we think there is too much air turbulance down there at high speed trimmed out and tabs down.

so thats that

[mrfixxall]

i just got back from an outing, and i have a weird problem. my 290a outdrive when at 2 degrees tilt to negative 4 degrees well the engine cools fine runs at 160. i have a 142 degree thermostat. all my pumps on the engine are new. when i tilt the engine to like 7 to 9 degrees the engine gets hot right away, and when i slow down or tilt down it cools down right away. any one have any thoughts.:bonk:


mine did the same thing,,i replaced my impeller now its fine..

[tom freeman]

i had a small leak on my shakky pump and impeller, i thought it was the problem... replaced the pump and the impeller and i still have the problem.

[Michi Besler]

who has got experience with with a whipple charged 496 HO in a 22 classic concerning water cooling! Do we need to replace the regular waterpump by a double stage one (like Hardin)?
Is the original water pick-up big enough for the larger pump performance?
When using the original waterpump, would work a transom water pick-up for the charger cooling be enough? (do we need an water pressure relieve valve?)
I hope very much someone can help me, unfortunately here in good old Hamburg/Germany we don´t have performance marine engine community!!
Thanks a lot
Mich Besler

[maddad]

i just got back from an outing, and i have a weird problem. my 290a outdrive when at 2 degrees tilt to negative 4 degrees well the engine cools fine runs at 160. i have a 142 degree thermostat. all my pumps on the engine are new. when i tilt the engine to like 7 to 9 degrees the engine gets hot right away, and when i slow down or tilt down it cools down right away. any one have any thoughts.:bonk:
The O rings that seal the differant sections of water tube sometimes fail and let the cooling loop get air bound. I changed my boat so I get the water through the hull. I was told everyone with an older Volvo should consider that change.

[jl1962]

Same problem. I added a freshwater intake on my '67 Ski Sporter last summer. Runs really cool now.
:yes:

[silverghost]

Back to the original thread question on an EFI computer controlled engine & T-stat.
I agree wi-th Cuda.
Always use the proper T-stat on a computer controlled EFI engine, spercharged, turbocrged, or convntional EFI.
One of the main sensors that the EFI "Black Box" computer looks at is the engine temp sender.
If you remove your T-Stat the EFI computer will think your engine is always cold & warming-up. The EFI computer will keep the engine in the rich fuel warm-up "choke" mode waiting for the warm-up that never happens.
This will not improve engine perfrmance !
Quite the reverse ~
The result?
Far to rich a fuel mixture and poor fuel mileage.
Engine oil never gets hot enough to evaporate codensation. or flow properly; especially in colder water & weather.
Timing is also retarded during the warm-up mode~
Overly rich fuel mixture causes oil to wash-off of the cylinder walls & rings.
Gasoline will soon build-up & dilute engine oil.
The result abnormal engine wear.
I would always use the EFI builder's recomended T-Stat.
A good Robert-Shaw performance T-stat will give you the extra flow needed in the event you need more engine cooling to prevent an engine over-heat during, and after a hard run.
Transom-water pick-ups are great~ unless you are one of thiose guys who go airborn all the time with your transom out of the water much of the time. Then the lower outdrive pick-up migt be better with a blue BARCO pump. impeller.
Just my two cents~
Others ideas may differ~

[Dr. David Fleming]

Never thought about the T stat being used differently in a fuel injected engine - learned a bit here - nice post.

Any opinion why the blue merc 500EFI pulls extra water out of the T stat housing into the lower and also upper headers? we are talking four heater hose size water lines from the T stat housing?