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Inciong_A
08-23-2000, 10:25 AM
I just put in a new Ford 460 in my 21-foot Sleekcraft. The boat has a Berkeley jet. At cruising speeds, the temp reads 150. However, as soon as I idle, the temp starts to creep up to about 210 or 220. What could be causing this? Thanks in advance.

dropkeel
08-23-2000, 02:46 PM
You need a water bypass regulator.Available from Greg Shoemaker Marine . Those pumps are capable of putting 100lbs or so of pressure through the engine.Too much for a automobile engine that the cooling system was designed for 15-17 lbs of pressure.Enough to blow head gaskets and intake manifold water jacket gaskets.Especially with a 460 Ford that does not use as many head bolts as a Chevy.
What you are doing is setting the in coming water low enough to let the motor heat up when running but as rpm falls so does the amount of water running through the system.Then it overheats and I got to tell you 220 is too hot!
Buy the regulator,set the water for 180 degrees and it will will dump out the remaining high pressure water at WOT.Must put a resrticter valve in the out bound water to help pressure up the system though.
Does this make sense?

Inciong_A
08-23-2000, 04:46 PM
Originally posted by dropkeel:
You need a water bypass regulator.Available from Greg Shoemaker Marine . Those pumps are capable of putting 100lbs or so of pressure through the engine.Too much for a automobile engine that the cooling system was designed for 15-17 lbs of pressure.Enough to blow head gaskets and intake manifold water jacket gaskets.Especially with a 460 Ford that does not use as many head bolts as a Chevy.
What you are doing is setting the in coming water low enough to let the motor heat up when running but as rpm falls so does the amount of water running through the system.Then it overheats and I got to tell you 220 is too hot!
Buy the regulator,set the water for 180 degrees and it will will dump out the remaining high pressure water at WOT.Must put a resrticter valve in the out bound water to help pressure up the system though.
Does this make sense?
The only way I could think of which will fix the problem the way you describe it is to put the water bypass valve (WBV) in a passage other than the main water line to the motor. What I want is to INCREASE the water flow at idle, not at full throttle. Do you mean that the WBV should go inline with the hose coming from jet? If I understand WBVs correctly, they close at low temps and open at high temps. Currently without a WBV, I'm already running hot at idle. Sounds like the WBV won't fix this as it would still be open. Thanks for the input. I'll also try calling Greg tomorrow.

dropkeel
08-23-2000, 06:23 PM
No, reread my post.It will fix you up. http://free.***boat.net/ubb/smile.gif
Yes you need to put it inline with the water coming from the pump.An additional transom port will have to be drilled for the bypassed water.
Shoemaker will probably be in my home state doing the ESPN thing for the Choteau Bend Race this weekend.

Inciong_A
08-23-2000, 10:33 PM
Hi Dropkeel,
I truly appreciate your help here but I still need enlightenment. Let's assume that I installed the Water Bypass Valve (WBV) per your suggestion. What would happen to the the WBV once I idle and the motor starts to creep up? If I understand you correctly, the WBV will divert all of the water from the jet into the motor and none out the new transom-mounted exit path you mentioned. Do I understand this correctly? If so, how would this be any different than how my plumbing is currently set up? Currently, at idle, all of the water is being diverted to the motor and it still heats up to 220. Unless there is more water flow as a result of the WBV, I can't imagine how it would be any different than what I have today. Is there a motor/pump associated with this WBV you are mentioning? Again, thanks for your input.

Jerry Buckner
08-28-2000, 06:57 PM
I was just reading about your overheat problem. My 454 used to heat up a bit at idle. Not as much as yours thou. The first place the water flowed after the pump was into the exhaust manifolds, then into the front of the engine thru the block, then out the thermostat housing then out thru the risors. My problem was keeping heat in the engine at speed. I installed a Rex Marine thermostat kit which helped build more heat. The engine still wanted to heat more at idle. I recently installed a set of Lightening headers. Now the exhaust manifolds/headers is the last place the water flows before exiting. The engine no longer heats up at idle. I dont know what kind of exhaust you have but if it flows thru the exh manifolds first maybe you could re route this and stop warming the water before it enters the engine. Just a suggestion. I'm sure Greg would know what to do. Good luck.