"G'day Ricardo,
I reall
"G'day Ricardo,
I really appreciate the way you put things into perspective. As you put it, "I am in over my head", regarding the Cooling side of things, which is the reason I am here wanting to get it right the first time.
I am wanting to keep the Closed System operating as efficiently as possible, and therefore, will be going to a 180 F Thermostat for the engine itself, and a 15 PSI Pressure Cap to keep things under control.
One thing I didn't want to do was "Over-cook" the water keeping the Exhaust Manifolds cool which in turn would pre-heat the coolant in the HE before it went back into the engine via the Water Pump.
Yes, the engine I am using is a pre 1974 V6, and was last used by Buick in 1967, and OMC still used it for a few more years. There is nothing here for these engines, in either the Marine, or Auto versions, as they never were imported into Australia, and therefore, I am attempting to utilise what I have here to create a Closed System from a fully operational Open System.
I am a modifier of cars, and am aware of the requirements of correct cooling, but this little exercise is creating a few sleepless nights trying to figure it out. I am also a Shipwright by trade (Long ago) but only worked with outside-the-hull Heat Exchangers in smaller vessels, or Raw Water cooling in larger commercial vessels. But then it was working on the Hull Repairs and maintenance (99% of the time) and fitting engines to Specifications. Never had to worry about what happened after it left the Slipway, as the Owner had those worries.
The reason I wanted to keep Coolant in the Exhaust Manifolds as against Raw Water, is to stop the corrosion, and encrustation that hot Salt Water causes due to heat.
This vessel will never see Fresh Water again, as it will from now on be used totally in Salt Water. Lakes are for fishing in, and there is sufficient waterways around our little Island of Tasmania to keep me interested in until I kark it.
With regards to sending the spent Raw Water to each of the Manifolds, I was going to use "Y" pieces in the outlet hose from the HE, so that the actual lengths of the final hoses could be made the same, so that the water wouldn't favour one side against the other, and therefore promote even cooling effects.
Okay, now for the placement of the HE. I can run it any way, length-ways, cross-ways, or diagonal, so where would be the best place to sit it? Up high, mid, or low down? That is, in relation to the Manifold Outlets? Is it better to use the Raw Pump to push the water up to the rear of the Manifolds after it leaves the HE, or let it flow down to the Manifold?
Quote: "Nobody here, in my area, seems to know what is required. Everyone only looks at Parts Books, and need Specifications and engine numbers and the like, which I don't have."
By this I meant that all of the people here I have found only know about the stuff they sell, like Outboards, and the like, and none have "Experimented" with the out-of-the-ordinary, like I am trying to do. Racing guys used Raw Water cooling and rebuild everything after the day's racing. "Normal" boat owners just use what they have, and what comes from the factory.
If it isn't listed in the Parts Book it can't be used, etc. But, I have finally found a place where I can get things like Gaskets and the like for the Stern Drive, but NOTHING for the engine or manifolds. Everything has to come in from USA, and that means big freight costs, and time.
Morten,
Thanks for posting the site, and I have printed out the section which gives me other things I didn't have before. The full description of the operation of the Thermocon Develvo System has caused me to re-think the use of the Pressure Relief Valve, and whether I need to use it, or simply eliminate it, and run the Raw Water directly from the pump to the HE, then from the HE to the Risers. As it won't take long for the HE to fill up and outflow to the Risers.
Bruce.
PS. I have totally forgotten the thing about gravity convection. I know all about Gravity, as I usually experience it during things I do, and it always hurts when the fall stops being a fall."