Another Heater Question

[dan1166]

My 1999 SN has a GT40 engine. I purchased the boat new and shortly after installed a heater. Heatercraft's directions say to hook up the heater at the temp. sensor to feed the heater and return at the bottom of the large elbow between the thermo housing and the engine water pump. This worked so so but only at high RPM's.

My friend purchased a new 2000 SAN, GT40 motor with a factory installed heater, and his heater put out much more heat. His return line went into the starboard side of the engine where the drain plug is located.
So I changed my return line to the same location and the heat was improved. Now I see that heatercraft is recommending a Y connection before the raw water pump to draw the water through the heater core. This will give you more heat during idle operation. Makes a lot of sense to me, but here is my question.


If the heat was improved by returning to the side of the engine block, and they use the side of the engine block(Port or Starboard) to feed a shower system, then which outlet is feeding the heater? The top of the engine or the side of the engine block. To get the most effiency out of the heater with the new Y connector, it would be nice to know where the most hot water is coming from. The top of the engine is a larger outlet size,(I think1/2") and the water is hotter at this location. However, the side of the engine where the drain plug is located, has only a 1/4" outlet. Maybe the thing to do would be to install a short peice of clear tubing to see which way the water is flowing. That is the only thing I can figure. Your thoughts and opinion's would be greatly appreciated.

[jncbabcock]

RE: Another Heater Question

I have a 99SNOB with the Apex. I can send you a picture of how mine is set up if you think that will help. Chevy or Ford I would think the hook up would be the same. I get very hot water @ idle, and a stronger spray if I slightly rev the engine.

What is the condition of your thermostat? I do know that the temp has to run higher in order for it to produce enough heat.

Jason

[Laptom]

RE: Another Heater Question

As far as I know, the best way to install it is: return by the Y connection before the raw water pump and the feeder is at the thermostat. I did this last year and had no problems at idle or higher rpm's.

How is the standard configuration from Correct Craft now day's (for 2006 boats)? Anyboady knows?

[NCH2oSki]

RE: Another Heater Question

I have the Y connection in my 99' ski with a gt-40. I used the temp sensor at the top of the engine and the Y is at the raw water pump. My heater works great.

[M3Fan]

RE: Another Heater Question

Yep, the ideal feed is from the top of the engine. The return is the Y fitting before the RW pump.

[wake_fun]

RE: Another Heater Question

Look in my photo album for pics.

[core-rider]

RE: Another Heater Question

With the return routed to the 1/4" engine block fitting the water flow would be slower which means more heat could be transferred the air, but all those adapter fittings to make it works looks horrible to me. If I understand the other routing correcttly, the return is before the rae eater pump? So your returning warm water to the cold water from the lake. That seems odd, but I don't really see any problems caused by it. I would think that way would casue the water to be pulled through the heater core and not warm up the air as much. I guess I need to look at how my 03 Excaliber is routed tonight.

[dan1166]

another heater question

Hi Core-rider;

Did you have a chance to look at your heater core plumbing to the engine? I am curious, but I think the excaliber returns to the engine water pump. Let me know.

Dan

[core-rider]

RE: another heater question

Yeah, it goes to a 1/2" fitting to the engine water pump. I had a problem with my heater not putting out enough heat once in awhile and it turned out the be a kinked hose at the heater. The factory left too much length and just bent it around causing the hose to kink. I cut away the extra hose about a week ago but haven't had my boat out yet to see if it works any better.

[dan1166]

Another Heater Question

This question is for wake_fun;

You are showing one heater hose hooked up at the temp. sending unit and the other is at the drain on the side of the engine. So my question is what hose is supplying the heater and what hose is returning to the engine? Both are positive pressures but one must be a little more pressure than the other. Heatercraft is telling me that this will never work and is recommending a Y connection before the raw water pump for a return. If I return to the engine via raw water pump, what do you think will be a better supply of hot water. The top of the engine, or the side of the engine. Read my original post for more details.That was my original question on 2/22/07.