Best place to get hot water from engine for heater

[jimmylee1000]

As you probably have seen, I just installed a heater in my 1993 Ski Nautique with the Pro Boss engine. I took hot water to supply the heater from the engine drain plug on the driver's side. Was that the best place for the hottest water and most flow? Is there another better place someone could spell out for me or send me a picture of?

[G-man]

I have always got it on the left side of the block but I don't think it makes a difference.

[WakeSlayer]

Pull from the intake, return to the circ pump.

[jimmylee1000]

Pull from the intake, return to the circ pump.

What, exactly, does "Pull from the intake" mean? The raw water intake is cold. I am not sure exactly where you mean. Can you give more explanation or post a picture?

[Nordicron]

?????

What, exactly, does "Pull from the intake" mean? The raw water intake is cold. I am not sure exactly where you mean. Can you give more explanation or post a picture?

That confused me as well! I'd think the warmest water would be just before the t-state housing or perhaps on the exaust manifold.

[DealsGapCobra]

I think he means pull from the intake manifold.

[WakeSlayer]

I do mean the intake manifold.
Some of them have a plug that you can remove and stem off of. Some already have a capped stem. If you have neither, the heater kits typically come with an T adapter that allows you to remove your temp sensor, install the adapter, re-install the temp sensor, and take the hot water off the T part of the adapter. This is the best place to get the warmest water for your heater. If you take if off the block it is already cooling the engine and will have lost some of the heat you are after.

[jimmylee1000]

I do mean the intake manifold.
Some of them have a plug that you can remove and stem off of. Some already have a capped stem. If you have neither, the heater kits typically come with an T adapter that allows you to remove your temp sensor, install the adapter, re-install the temp sensor, and take the hot water off the T part of the adapter. This is the best place to get the warmest water for your heater. If you take if off the block it is already cooling the engine and will have lost some of the heat you are after.

I hate to labor the point, but I really still don't get this. You state "if you take it off the block it is already cooling the engine and will have lost some of the heat you are after." This doesn't make sense to me. The water gets its heat from the block, and does so by cooling the engine. I would think you want the water would be at its hottest after it has had maximum contact with the engine block.

[WakeSlayer]

I did write that poorly, really poorly. My apologies. I meant that the water had not warmed up enough yet......
Your water is being heated by the block. Then by the heads, and it reaches its highest temp as it gets to the intake manifold, and has the most pressure there, prior to opening the thermostat, and also where it passes the temp sensor (alternate attach point for heater feed tube). Sorry, I was not paying attention. Nonetheless, trust me on this one. Feed your heater from the intake manifold. Return it to the circulation pump.

[jimmylee1000]

I did write that poorly, really poorly. My apologies. I meant that the water had not warmed up enough yet......
Your water is being heated by the block. Then by the heads, and it reaches its highest temp as it gets to the intake manifold, and has the most pressure there, prior to opening the thermostat, and also where it passes the temp sensor (alternate attach point for heater feed tube). Sorry, I was not paying attention. Nonetheless, trust me on this one. Feed your heater from the intake manifold. Return it to the circulation pump.

Thanks. Will do tomorrow. I need the water at its hottest point. I hope there is already a port on the intake manifold. But it will be hard for me to tell since I have no clue where the intake manifold is or what it looks like. I'm sure it is simple, I just don't know what or where it is on my PCM Ford 351 engine.

By the way, the pressure is actually highest immediately at the pump discharge. No question. I promise. The pressure will drop continuously as the water flows through its flow path and eventually has no pressure as it exits the exhaust. You will get the most flow through the heater by taking the water as close to the pump discharge as possible. But you may not get any heat since the water may not be hot at that point. I'll take a little less flow if the water is a lot hotter.

Great input. If you know of any pictures showing exactly where I can get a slipstream for my heater off the intake manifold, I'd appreciate it.

[WakeSlayer]

The intake manifold is the part that your carb is bolted to. You will have a temp sender that looks sort of like a brass spark plus shaped part and has a wire on the top. The wire should be yellow. Remove that, install the T adapter (no thread sealant, re-install the the temp sender on the top of the T, again, no thread sealer. Take your heater hose off the center part of the T. If you use thread sealer, you will lose the ground that makes your sender work properly.

http://www.heatercraft.com/images/Do...tal_Marine.pdf

This is a 289, but you can see my additional port on the top of the intake manifold. The temp sending unit is behind the disty on this motor.

[jimmylee1000]

Wakeslayer rules!

The intake manifold is the part that your carb is bolted to. You will have a temp sender that looks sort of like a brass spark plus shaped part and has a wire on the top. The wire should be yellow. Remove that, install the T adapter (no thread sealant, re-install the the temp sender on the top of the T, again, no thread sealer. Take your heater hose off the center part of the T. If you use thread sealer, you will lose the ground that makes your sender work properly.

http://www.heatercraft.com/images/Do...tal_Marine.pdf

This is a 289, but you can see my additional port on the top of the intake manifold. The temp sending unit is behind the disty on this motor.

Installed the 160F thermostat, and moved the heater supply line to the top of the intake manifold exactly as Wakeslayer outlines above. The heater is now HOT, HOT, HOT! Very nice indeed. Thank you for your help and excellent advice.

[jimmylee1000]

I did it and pics are attached!

The intake manifold is the part that your carb is bolted to. You will have a temp sender that looks sort of like a brass spark plus shaped part and has a wire on the top. The wire should be yellow. Remove that, install the T adapter (no thread sealant, re-install the the temp sender on the top of the T, again, no thread sealer. Take your heater hose off the center part of the T. If you use thread sealer, you will lose the ground that makes your sender work properly.

http://www.heatercraft.com/images/Do...tal_Marine.pdf

This is a 289, but you can see my additional port on the top of the intake manifold. The temp sending unit is behind the disty on this motor.

Thanks again. Great advice, and it worked wonderfully. What a huge improvement in heat output from the heater. Pictures attached of the change.