Low RPM heater Mod Question

[SmoothWaterMan]

Don't drill it out. The 1/8" hole is there for a engineered reason, it provides the proper water flow through the heater.

thealy, don't worry about the mfg's reasoning, see the instructions from heatercraft.

Peter

[trevorb]

Don't drill it out. The 1/8" hole is there for a engineered reason, it provides the proper water flow through the heater.

thealy, don't worry about the mfg's reasoning, see the instructions from heatercraft.

Peter

Thanks,

I was just wondering if anyone tried drilling it out. I'll leave it alone. It gets good heat the way it is. It's the engineer in me that always wants to make things just a little better.

Edited May 11, 2006 by trevorb

[thealy]

The attached quote is from G-Pac regarding an over heating issue he has heard of. After listening to this new post, I am now a bit concerned about making any mods to the onboard heater. Any one have any thoughts or comments?

... In addition, for those of us with the HH engines and fresh water cooling systems AND heaters, there is an issue identified by Indmar with low coolant fluid levels due to the heater option. I will try to get a better explanation for this, but I think the heater ties into the fresh water cooling system at some point and increases the system's coolant capacity and requires a topping off of the coolant above and beyond the manufacturer's specifications for engines NOT equipped with the heater.

...

G-Pac

[gonorth]

I sprung a leak in my heater core this weekend and ran across this discussion while doing a search. It has peaked my curiosity as to how mine is hooked up as I have little heat at low RPM too.

Mine is hooked with lines to intake manifold and another to the side of the engine water pump. No dedicated water pump anywhere along the heater hose. Does this mod you guys are talking about with a Y adaptor before the sea water pump assumeing an inline heater pump or just the engine doing all the pumping?

[areamike]

Don't drill it out. The 1/8" hole is there for a engineered reason, it provides the proper water flow through the heater.

thealy, don't worry about the mfg's reasoning, see the instructions from heatercraft.

Peter

Weird.

I read the install instructions from heatercraft and it says to install one hose on the manifold plug and the other on the raw water pump plug. Doesn't that go against what everyone is saying?

2. Locate and remove the cooling system plug on the intake manifold. This would be located at the front of

the engine near the thermostat housing or on the thermostat housing itself. (On some applications it may be

necessary to rmove the temperature sending unit and install a brass tee.) Install the proper size hose barb.

3. Locate and remove the plug on the water pump hosuing and install the proper size hose barb.

4. Cut the water/coolant hoses to length, attach with hose clamps, and secure in place.

That is how mine is installed and at idle, my heater is cold.

So, I need to remove the hose from my water pump, plug it back up and then put that hose where??

[VinRLX]

'Normal' installation had hot water coming from manifold, that doesn't change. Pulling it through the core was the circulation pump, on the motor, near the pulleys. However, that did not provide enough 'suck' to circulate warm water at low RPM--idle speed or nearly so.

To get heat at low RPM, you need the 'Y' fitting. Take the hose from the circulation pump and plug that hole in motor. Install the Y fitting in the 1.25" raw water line (the one that starts at the hull of the boat and goes to the impeller). The branches of the Y face against the flow, the base of the Y face with the flow. The factory now installs this fitting with the heaters, but places it after the impeller. However, if installing yourself, you'll be happier with install before the impeller, IMHO.

[areamike]

'Normal' installation had hot water coming from manifold, that doesn't change. Pulling it through the core was the circulation pump, on the motor, near the pulleys. However, that did not provide enough 'suck' to circulate warm water at low RPM--idle speed or nearly so.

To get heat at low RPM, you need the 'Y' fitting. Take the hose from the circulation pump and plug that hole in motor. Install the Y fitting in the 1.25" raw water line (the one that starts at the hull of the boat and goes to the impeller). The branches of the Y face against the flow, the base of the Y face with the flow. The factory now installs this fitting with the heaters, but places it after the impeller. However, if installing yourself, you'll be happier with install before the impeller, IMHO.

ok so I get this right...

The branches of the Y go against the flow. So one branch goes to the 1.25" hose that goess to the hull, the other branch needs to go to the heater hose and the base of the Y goes to the 1.25" hose going to the impeller pump??

If that is the case. Do they make a Y fitting with one branch smaller for the heater hose or will I need to do some adapting to get that diameter for that branch smaller?

Edited April 23, 2008 by areamike

[VinRLX]

ok so I get this right...

The branches of the Y go against the flow. So one branch goes to the 1.25" hose that goess to the hull, the other branch needs to go to the heater hose and the base of the Y goes to the 1.25" hose going to the impeller pump??

If that is the case. Do they make a Y fitting with one branch smaller for the heater hose or will I need to do some adapting to get that diameter for that branch smaller?

You got it. The Y comes ready to install, one small branch one large branch. Double-clamp if possible, as you should with anything below the water line of the boat.

[DizzyG]

on our '06 VLX I'm fairly sure our Y is after the pump. So I can just move that and plug the hole and have hot water at low RPM?

[areamike]

on our '06 VLX I'm fairly sure our Y is after the pump. So I can just move that and plug the hole and have hot water at low RPM?

There's no hole to plug unless one of your heater hoses is going directly to your Water Pump. If it goes to a Y already, then simply move the Y to the intake side of the impeller housing instead. Then just butt connect where you remove the Y...from what I understand.

[DizzyG]

I don't think it's on the same size hose as my intake hose from what my memory is telling me. I haven't looked closely at it since I winterized it in November, so it could just be my memory. Otherwise I already have a Y in place for my ballast system, I could just put it in that area.

[Molarbu]

on our '06 VLX I'm fairly sure our Y is after the pump. So I can just move that and plug the hole and have hot water at low RPM?

I did this last weekend on my boat and I haven't had it out yet to check and see if there's much of a difference. It's pretty simple, only about a two raw knuckle job. Oh, you have a v-drive, you may have more raw knuckles and a headache from dangiling upside down. The reinforced hose from the hull to the pump is a #%#^$@ to work with.

[areamike]

I just went to 3 hardware stores and two Automotive stores and cannot find the Y fitting needed for this mod. Heck I never even found a Y fitting that was 1.25 barbed.

[VinRLX]

Order from Heater Craft. The smaller branch of the Y has a specific size hole in it--not as large as the branch or hose itself.

[jimw]

I just received my Y from Heater Craft. They are very proud of this hardware is all I can say. I almost wanted to pull the old one off of my 00 Sunsetter for sale but decided to leave it on for the next owner.