Thermostat with Bassetts

[Taylorman]

Ive seen the plumbing diagram on liquidaddiction showing how to plumb Bassetts with a Rex t stat. Im wondering if anyone has ever tried to plumb Bassetts the same way with the t stat as without.
Here is what im thinking about and Im wondering if anyone else has ever tried this and what the results were. Obviously go from pump into engine front plate. Then from the t-stat, the top holes go down to the t's on the water inlet plate. Then one bottom hole of the t stat would go to the Bassett t valve then to header water lines and the other bottom hole would dump overboard just as if there were no t stat. If been thinking about whether or not this will work with the t stat opening and closing.
I think it will work when the thermostat is open just as it does with no thermostat. However, when the thermostat closes and water starts to flow from the t's in the front water inlets to the top holes of the t stat, this open the bypass in the t stat causing high pressure water to hit the bassett t valve and forcing it open. No big deal except at idle.

[Oldsquirt]

Kevin, I'm not too sure what exactly you are asking here, or what you are trying to accomplish.
Do you already have a t-stat setup and are contemplating removal of the thermostat from the system? If you do remove the thermostat you will also need to remove the bypass hoses that run from the water plate to the top of the thermostat housing as well as the bypass valve and spring. It would be easiest to just replace the entire 4-port tower assembly with a standard 2-port outlet. One hose would be the dump line and the other would go to the Bassett t-valve.
I hope you understand that those two bypass hoses and the bypass valve inside the t-stat tower are there to provide a path for water to flow to the headers and out your dump line at all times. Without the bypass, the closed t-stat could cause an over-pressure situation in the engine block.
If you remove the thermostat, but leave the bypass hoses installed, you will only get a partial flow of water through the engine block. Without a thermostat inside of a 4-port t-stat tower, the bypass valve cannot be installed. It's spring has to rest on the top of the thermostat.
Make any sense?

[Rexone]

The tee valve will not see any more pressure thermo open vs. closed. The shuttle valve within the thremo housing simply keeps water flowing to the exhaust (whatever type of exhaust you have). It should work. However with wide open dump line you have no way to fine tune the pressure to the tee valve so you may end up with it opening late or early depending on size of dump...every boat is different which is the reason a ball valve on the dump line is recommended. The tee valve is simply a check valve which opens at x amount of pressure. If you can't regulate the pressure the tee valve sees you are at the mercy of the tee valve spring as far as when it opens and closes.
:)

[Taylorman]

Sorry for the unclear question. I don't have a t stat now but thinking about getting one. My question is how to plumb the water with one with Bassettss. I totally understand how the t stat works.
My plumbing now is such that water out of intake goes to t valve and other line goes to overboard dump.
My question is this. When you add a Rex t stat, do you leave the plumbing to the headers the same in the bottom holes and add the bypass lines from the top holes in the t stat to the t's in the water inlet on the front of the block.
Im trying to see if this will work as opposed to this setup. This diagram, although functional is more complex than i want. I think this is how Lv jet has his set up.
http://www.liquidaddiction.net/images/dragnjet/cooling%20diagram.jpg

[Oldsquirt]

Originally posted by Taylorman
My question is this. When you add a Rex t stat, do you leave the plumbing to the headers the same in the bottom holes and add the bypass lines from the top holes in the t stat to the t's in the water inlet on the front of the block.
Yes, that's exactly the way to do it.
LV's way will also work. His idea was to simply divorce the header water from the engine cooling water.

[LVjetboy]

Taylorman,
Oldsquirt's right. The routing in your last post will work. My routing was a modified approach which worked well too. I liked my routing because (refer to diagram):
1) 1/2 ball valve on the hard line is primarily a safety shutoff but can also limit maximum full throttle pressure. I ran this about 3/4 open because I had some weak gaskets on old engine...anything more and milkshake from 30-35 psi full throttle pressure.
2) 3/8 main header coolant control valve controls header pressure. This replaces the dump valve control of t-valve pressure Rexone mentioned...but I normally ran full open except for driveway testing when I fine tuned for garden hose pressure. If you run a t-stat and reduce flow, you adjust based on idle max. temp.
3) Two #8 dump lines off the bottom T-Rex housing reduces back pressure on the engine. I still have this system today (minus the thermostat) for a 100 mph jet boat. That without a pressure regulator. Runs 25 psi full throttle (6200 rpm) If I had only one dump line and the other to the headers I may overpressure the engine or need a regulator. That because the header supply line with a t-valve and header injection nozzles would be more restrictive than a #8 straight to the transom.
4) No dump line valve. This is controversial. There's the issue of pressure effect on head or engine block hot spots. My thought is all jets (and v's?) should have a coolant pressure gage. But most jets only have a temp gage, if that. Based on temp alone, a resticted dump line may overpressure your engine at full throttle if adjusted wrong and you have no pressure gage. Whereas a restricted inlet line adjusted to maximum idle temp may not. But this point open for discussion.
5) 1/4 ball valves to the headers helps balance header cooling. This handy when one header flow or the other is restricted with debris or line length...etc, and becomes unbalanced. These added "complications" or expense are not absolutely necessary, but nice to have.
6) Line routing more symmetric. Symmetry to me is a good thing. Both pleasing to the eye and functional.
Overall, my cooling design is similar to Bassett's "approved" design in many ways. The absense of a dump line valve and the header cooling line routing are the key differences.
jer

[Taylorman]

Why are you running this same setup minus the thermostat?
Explain what you mean here.
There's the issue of pressure effect on head or engine block hot spots.

[LVjetboy]

"Why are you running this same setup minus the thermostat?"
Because my builder said run cool at full throttle. Cool defined by him about 120 F. I've got al heads and big timing. I tend to do what my builder says. This is not the mild 454 I had before.
"There's the issue of pressure effect on head or engine block hot spots."
Lower block pressure means more likely a hot spot producing a vapor bubble and subsequent metal damage. I think this is most likely at idle than full throttle, depends on pressure vs. engine temp. Whether this is more likely with inlet regulated maximum pressure or outlet regulated maximum pressure I'm not sure. My guess is either system represents the same risk of hot spots. But that a guess. Just that outlet regulated more likely to screw up in other ways. Pick your poison.
Don't get me wrong, I ran my mild 454 with a variaty of systems (never outlet regulated though) And they all worked to some extent. Just some better than others.
jer