Water temp

[raisinL]

My buddy has a tahti with a amc 360 while running it it's at 180 degrees if he slows down less than a min it runs up to 220 degrees any ideas? Mine with a bbf runs at 150 degrees all day. Thanks

[Jetaholic]

If he has a gate valve (i.e. standard "garden hose" type valve) in line with the plumbing coming from the pump, he needs to open it up more.
With the boat sitting at idle in the water, you open it until it idles at 180*. Once he's moving the temp will drop, but it should go no higher than 180 at idle.

[raisinL]

Sounds logical I should have mentioned his pump is a panther. Same principal though I will check this out and Thanks.

[460 jus getn it]

Rule of thumb, the temp should drop about 40 deg when the boat is running. My boat(bbf) idles at 150 and runs at 110 while under operation. I would say check the water comming in and going out, chances are you need to open up the valves asome like jetaholic said.

[TahitiTiger]

Correct me if I am wrong, but I heard that you should not exceed 12psi of water preasure to the heads at WOT. (btw mine is a 455 olds). So I have a water psi gauge and a temp gauge, with the psi at about 10 psi it runs a happy 140* on the average.

[Jetaholic]

Well the best way to do it is to run a water bypass valve in addition to the gate valve if you're not running a thermostat. The bypass is a ball and spring valve that opens at 12-15psi and dumps the excess water pressure overboard. Then you just adjust gate valve for water temp on a non-thermostat system.

[SmokinLowriderSS]

The only time you should need to worry about a pressure build-up is if you run a restricted water outlet such as OT headers. Then you need a bypass valving to an overflow.
Log manifolds and thru transom headers should have more outflow capacity than inflow capacity, no extra valving or overflow complications are needed.

[460 jus getn it]

I dont run any of these. I have one valve comming in and one going out. The exit valve is wide open and the incomming is turned 2 1/4 turns down. I run open headers and have never had an issue.

[WET-N-WILD]

I took my gate valve out. I couldnt keep my boat cool in the long 5mph zones. I even had to run my hoses different.....I ran them stright into the block then into my water logs, then through the muffelers and out? I have a daycruiser, with a 460, and berkeley pump. Now I run 160 running and 200-220 in the 5 mph zones. It changes depending on where I'm at.

[SmokinLowriderSS]

I took my gate valve out. I couldnt keep my boat cool in the long 5mph zones. I even had to run my hoses different.....I ran them stright into the block then into my water logs, then through the muffelers and out? I have a daycruiser, with a 460, and berkeley pump. Now I run 160 running and 200-220 in the 5 mph zones. It changes depending on where I'm at.
That's wild. Check your inlet hose for a restriction somewhere. When my Taylor was new, it was not valved, it had a restrictor in the main inlet hose under the engine oil pan. Dad removed it because of idling heat issues and put the valve in. Unrestricted 5/8" hose feed is way more cooling than my 454 has ever needed.

[raisinL]

I took my gate valve out. I couldnt keep my boat cool in the long 5mph zones. I even had to run my hoses different.....I ran them stright into the block then into my water logs, then through the muffelers and out? I have a daycruiser, with a 460, and berkeley pump. Now I run 160 running and 200-220 in the 5 mph zones. It changes depending on where I'm at.
Seems to me it should'nt run that hot at idle. 200 is not real bad but 220 degrees is not a happy motor. How is the water flow at idle ?

[WET-N-WILD]

I replaced all the hose's!! We thought it was the pump, so pops and I took the boat to the ramp, left in on the trailer and pulled the hose loose on the back of the pump and aimed it outside. Wile he held it, I fired the boat real quik. At idel it was coming out like a strong water hose at your house. When I hit it, it got alot stronger. My dad thought maybe my water channels had sand and crap in them but then we had the motor rebuilt and now know its not that.

[sandwindersandcars]

Correct me if I am wrong, but I heard that you should not exceed 12psi of water preasure to the heads at WOT. (btw mine is a 455 olds). So I have a water psi gauge and a temp gauge, with the psi at about 10 psi it runs a happy 140* on the average.
i would be interested in knowing why you should not exceed 12psi, just about any radiator cap on any passenger car or truck is 16psi, and high performance vehicles comonly run 20-24# radiator caps. We run 22# caps on all of our LS1 equipped sandrails, i have also run that cp on my stockcars, also on my class10 desert car(toyota equipped) and never had any sort of leakage or gasket type problems.
just wondering what marine related would be the need to keep the pressure so low.
does anyone else know why, or is 12-15psi for the bypass valve a number that was picked to maintain pressure in the lines to keep a strong flow but could have been just as easily 20psi.:confused:

[TahitiTiger]

i would be interested in knowing why you should not exceed 12psi, just about any radiator cap on any passenger car or truck is 16psi, and high performance vehicles comonly run 20-24# radiator caps. We run 22# caps on all of our LS1 equipped sandrails, i have also run that cp on my stockcars, also on my class10 desert car(toyota equipped) and never had any sort of leakage or gasket type problems.
just wondering what marine related would be the need to keep the pressure so low.
does anyone else know why, or is 12-15psi for the bypass valve a number that was picked to maintain pressure in the lines to keep a strong flow but could have been just as easily 20psi.:confused:
As it was explained to me by my supplier, 12-15 psi was a safe water preasure to run at. Considering that on the car the rad cap would pop at 16 psi. I was also told any more than 18 psi and I would blow a head gasket. My boat though due to climate is happy at 10 Psi, I am sure in warmer waters I would need to open up my valve more.

[460 jus getn it]

i would be interested in knowing why you should not exceed 12psi, just about any radiator cap on any passenger car or truck is 16psi, and high performance vehicles comonly run 20-24# radiator caps. We run 22# caps on all of our LS1 equipped sandrails, i have also run that cp on my stockcars, also on my class10 desert car(toyota equipped) and never had any sort of leakage or gasket type problems.
just wondering what marine related would be the need to keep the pressure so low.
does anyone else know why, or is 12-15psi for the bypass valve a number that was picked to maintain pressure in the lines to keep a strong flow but could have been just as easily 20psi.:confused:Anything over 12 you run a risk of pushing water threw the exaust and into the oil. You also run the risk of blowing heads gaskets.