Logo
FULL SITE MENU

Heat Exchanger location

T

the_tassie_devil

Regular Contributor
G'day all,

I know I have asked this question before, but I thought it about time to get a definite response.

What place in the boat is the best location for a Tube type water to water Heat Exchanger?

My engine is a Buick 155 HP V6, and I can mount it about anywhere, so where is best.

Vertical?, Horizontal thwartships?, Fore and aft?, At the lowest point possible?, at Crankshaft line?, in line with the lowest point of internal coolant inside the engine block?

All recommendations appreciated.

Thanks,

Bruce.
 
Last edited:
You got the water hose coming in from the transom that runs down the starboard side correct. Wouldn't it be easiest to mount it that side level with the top of the motor? I think you have 2 plates there. Starter is on that side also ?

Hmm very, very good question. I loath to say the port side, you have the tilt solenoids that side low.

Hmmmm very good question !

Remember that i am going off the top of my head been a long time when i layed eyes on your motor.

Ok i'm gonna get out my book, and see what i can see you doing it today ?

When you need to know bye ?

Maybe someone else did one recently and can reply right now.
 
You know what i think horizontal front of the motor, reason i say that leaves you access to everything low for the sides, easy hookup for you and you can use the brackets there already to come off.
 
The reason I was thinking vertical, or inclined so that the top was in line with the top of the engine, is that as the hot coolant is leaving the engine, it is entering the HE as if it was a Radiator in a car, and the cooler coolant is at the bottom of the HE, where it is being drawn into the engine via the internal Water Pump.

This way, the cooler coolant is always going to be down low, and as we know, heat always rises to the top.

One of the "problems" I see with the H/E is that the inlet and outlet pipes are all on top of the housing, but the External Cooling Water flows in one end, through to the other end, back through to the first end then to the opposite end where it departs to eventually leave the vessel, via the Exhaust Manifolds.

The Closed Coolant only goes in one end, and out the other end and theoretically, the heated coolant staying in the upper part of the H/E cannister, if the unit is horizontally mounted.

My Solenoids are mounted on top of the Intermediate Housing, and there is virtually nothing on the Port Side of the engine, apart from the Fuel Pump, down low to impede the installation to Port.

Starboard side is totally different, with Starter, Oil Filter, Wiring, Solenoids, Battery, so Port Side makes sense as it will be a bit of a Weight Balance offset as well.

The plumbing isn't a problem as I will be using 1" Copper Tubing to direct the flow.

Lastly, I am thinking of plumbing the Raw Water from the Stern Drive directly to the H/E, then from the H/E to split to the Exhaust Manifolds, then from the opposite end of each Manifold to the Outlet pipes at the end of the Manifolds. This will mean that there is no need for retaining the 2 Lb pressure valves (pictured) in the first stage of the Thermocon Develvo System.

Thoughts?

Bruce.
 
Last edited:
I see alot of them horizontal, cant say i have seen any vertical, bit i don't see why not.

Funny about the solenoids always see them close to the tilt pump low. Usually mounted to the block right under the mani.

You know that might work out well plumbing it your way. Keep us posted, your expanding our knowledge with every post.

If one person goes your route after learning from your endeavor it will be worth the post.
 
Finally got the new installation working, and after testing it in my on-ground tank, I found that the main problem with the overheating was the Temperature Gauge incorrectly reading.

It was indicating up to 35 F hotter than the true temperature, which I was reading via a Laser Thermometer. I love those new Laser hand-held thermometers.

I did some electrical testing and found that with the ignition on, and the motor stone cold, the voltage at the Sender was reading 9 Volts, but with the engine running, just started, the reading was 10.5 Volts.

Seems like the Current for the gauges is not true, and requires a Resistor to maintain a true voltage that is required for the operation. Most cars run 8 Volts in a 12 Volt system, or 4 Volts in a 6 Volt system. This allows the gauges to still read correctly if the battery starts to go flat, even though the engine is still running.

Back to the H/E, it is working as I would expect, with the hot water at the top, and the cooled coolant coming out the bottom, back to the engine water pump. The Raw Water is cooling the Manifolds beautifully, and retaining the Thermoco Develvo's Manifold Splitter Valve, it assures instant cold water to the rear log to maintain the integrity of the rubber exhaust connector.

The mounting for the HE is 1/8" Stainless Steel that I had lying around, and it is bolted securely into place. Can't have that lump falling off.

The confines of the engine bay require a Header Tank with a bleeder hose to maintain a full head of coolant, and a means of filling the system and seeing how much is in there as well, and this is accomplished by installing a "T" into the Thermostat to HE hose.

The inlet of cold Raw Water from the Leg travels from the Leg, to the Blue Pressure Valve/Splitter, sending initial water to the rubber exhaust, and the rest to the top inlet of the HE, which instantly starts to cool the incoming coolant from the engine.

The Raw Water then passes out through the bottom of the HE, to a splitter (clamped to the bottom Stainless Steel pipe) that then directs the water to the front of the Exhaust Manifold coolant passages, then out each end, and across to the opposite log end to exit out the rubber hoses with the Exhaust Gases. Easier to run the hoses across the engine than try to risk crimping the hoses to come back into the same manifold.

If necessary, I will "fine-tune" the Raw Water to run from the bottom of the HE to the top and out, if it causes a problem, but static testing shows it looking good.

Real-time testing will be done soon, but I need to get the Gauge working correctly.

Bruce.
 
Last edited:
The engine is totally reconditioned, hence the new paint. New Valves, Rings Bearings, Cam and Lifters, Timing Set. No machining required for Crank or Bores. Rebuilt the Starter, Alternator, Distributor, Carby and Fuel Pump. Lucky I pulled it down before trying to start it as the Alternator was full of mud, the Carby and Fuel Pump was full of really BAD Varnish and crap, but for once, I didn't have to go the whole hog.

Bruce.
 
Taz good catch on the 67' drive question. Anyway i woke up and thought did the taz get to test his boat yet on the water.

Funny the first things pop in ones mind when one awakes.

You ever in the states and near NY give me a heads up i would love to run you around NY harbor in my pos.

Anyway keep us posted.
 
G'day Chiefalen,

When I wake up, I usually check if the body parts are still working.:D

Rain is forecast for the next few days, so seeing as I don't like to get wet, the second launching will have to wait a bit longer.

But, can't see me getting back to your shores any time sooner, or later. Trouble is with the financial's, or is that lack of. The want is there, and I have things I need, and want to stick in containers, but we will have to wait and see. Stuff is waiting for me in Florida, Connecticut, and New York, and seeing as postage is so dear...................

One day,

Bruce.

PS. My boat came from Auburn, NY.
 
Ahh fresh water boat.

Money is tight all over, thats why when people say buy this buy that i say wait, why buy what you don't need, when it comes to boat problems that is.

I have one child just finished collage and my second oldest is a boy he's going to the Univ, of New haven starting sept. So that ain't cheap.

Then i have 2 others, thank g-d i put the money away when i had it, so collage is covered for all 4.

Then things got tight all over i'm glad i never gave in to temptation and dipped into the collage money.

Oh well i have to make the 4 cars and the boat survive till they all move out.

Good luck and keep your chin up.
 
Yes, a Fresh Water vessel, but from now on in its' life, it is going to be a Salt Water vessel, and cold Salt Water at that. Last time I read it, the sea temperature around here is at 12C. Even in mid Summer, it only gets to around 16 or 17C.

Bruce.

PS. Still got 4 cars myself, but the kids are long gone from home.
 
Update on the Heat Exchanger.

Got to enjoy a couple of hours circulating around the Harbour yesterday, and I can report that everything wend beautiful with the new system.

Harbour Temperature was 55 F or 12.7 C, and 177 F at the engine to H/E hose.

Now to fix the Temperature Gauge on the dash which was moving between 190 F and 240 F.

WOT was 5,250 RPM and got 30 Knots, and at 4,000 RPM she was planing nicely at 22 Knots. Idling at 1,000 RPM gave me 3.5 knots, and no wake whatsoever. I love this boat, and she turns in its' own length.

Bruce.
 
Funny thing is that I don't have an Owners Manual to tell me what the WOT should be, but seeing as I built the motor, and the Cam was specially re-ground to marine specifications by a Cam Grinder here, I have no problems going that high, but it wasn't for long.

I just pushed the lever forward and it settled at 5,250, and didn't sound over-stressed.

The Cam in the motor had a couple of suspect lobes, and the Followers needed refacing, and as a replacement Cam wasn't available here, I just told the fellow what I had, and what sort of Revs I was looking at. He had some profiles that he thought would be best, and I am very happy with the result.

Next thing is to weigh the boat, in full trim, and then see what Prop Profiles might be best.

Bruce.
 
They can be built to turn that fast but stock valve springs have a real hard time getting the valves closed in time to rev much higher. Thats what happened to my 2.5L the just isn't enough clearance between the piston and valve.
 
Back
Top