What did you do with your GMT400 today...or yesterday....

[SnowDrift]

Thank you @Glagulator

 

[SnowDrift]

Husker said this:

When they switched sides with the accessories in 96IIRC there was a one year single stat before the dual stats. They're unicorns anymore I had one that I let get away not realizing what I had. It allows the DB2 pump to fit better on later year rigs

If a guy could obtain the unicorn, it sounds as though it's capable of doing the job, though, and allows a better fit for the DB2. Is that about right? I still wonder how much that '96 design will flow in comparison to the later dual thermostat design.

 

[Big T]

Husker said this:
View attachment 98481

If a guy could obtain the unicorn, it sounds as though it's capable of doing the job, though, and allows a better fit for the DB2. Is that about right? I still wonder how much that '96 design will flow in comparison to the later dual thermostat design.

This is interesting. Because of all the proponents of the single stat, I left it on the ‘94 which has the upgraded 130gpm water pump and the Dmax fan. However, it still runs warmer than my ‘99. I do have a dual stat crossover on the engine we took out of the ‘95, so I might just put that on the ‘94 based on Husker’s comments.

 

[Will L.]

Husker said this:
View attachment 98481

If a guy could obtain the unicorn, it sounds as though it's capable of doing the job, though, and allows a better fit for the DB2. Is that about right? I still wonder how much that '96 design will flow in comparison to the later dual thermostat design.

Look in my signature. Block off thermostat option. Follow the link.
Look at the size of those two. If a person is worried about flow restrictions through thermostat(s)- this would have maximum ability.

Also for the dual stats vs single-
It was already actually tested years ago. The single wins.
Someone can do it again if they feel the need.

I’ll try walking through it.
lets say the single stat has 2 square inch of flow area.
And the smaller duals has 1.25 each for 2.5. Now
Account for
100% of the coolant on the single going to the radiator. 2x100=200
75% of the duals IF you have a BRF. 2.5x.75=1.875.

Maybe my 1.25 is wrong?!!? Maybe it’s 1.5x2=3. Then 3x.75=2.25?????
Number theory is cute- but how much actually flows into the radiator and REMOVES HEAT FROM THE ENGINE- that’s what counts.

FOR EVERY PERSON you can find that has ran both the duals and the blockoff single stat- I am willing to bet there is 4 who attest to the single keeping temps more stable for less fan time, cooling off quicker when hot. Warming up faster on cold mornings.
You can find @WarWagon accounts of it here and other forums long before I joined.

Run what you have if it works. If not-then play with it. But as hard as it is to find any rare part- I would say get the ones that Nate found that are in my signature.

 

[dbrannon79]

Well I haven't been home long getting off work, maybe an hour, but I went outside to look at something on the truck and go out there to see this in the driveway! looks like I might be pulling the timing cover sooner than I want to. I know it's been leaking ever since I got the truck, but it hasn't been bad enough to warrant me to tear it down with all the work and time required to seal this up. I was hoping I could leave it be until I find another engine since this one is so worn out.




It's leaking from the passengers side top of the timing cover right where the coolant passage is from the pump on the block side. second pic is zoomed in right underneath the AC compressor near the fitting on the block for the turbo oil feed line.

 

[SnowDrift]

Mine got warmer than I like to see this past summer pulling our fifth wheel on flat ground for about a 10 mile trip. I had to turn off the A/C and haven't had to do that since before I replaced my radiator when I suspect it was plugged.

The cavitation mentioned in that dieselpage article makes sense and causes me to wonder if those involved weren't onto something.

Seems strange that a corporation would go to the expense to create a new part if they had one that was already superior.

I have looked at the parts in the link you mentioned several times.

I was just wondering if it would be worth the wait for the rare part if it has adequate flow.

 

[Big T]

Look in my signature. Block off thermostat option. Follow the link.
Look at the size of those two. If a person is worried about flow restrictions through thermostat(s)- this would have maximum ability.

Also for the dual stats vs single-
It was already actually tested years ago. The single wins.
Someone can do it again if they feel the need.

I’ll try walking through it.
lets say the single stat has 2 square inch of flow area.
And the smaller duals has 1.25 each for 2.5. Now
Account for
100% of the coolant on the single going to the radiator. 2x100=200
75% of the duals IF you have a BRF. 2.5x.75=1.875.

Maybe my 1.25 is wrong?!!? Maybe it’s 1.5x2=3. Then 3x.75=2.25?????
Number theory is cute- but how much actually flows into the radiator and REMOVES HEAT FROM THE ENGINE- that’s what counts.

FOR EVERY PERSON you can find that has ran both the duals and the blockoff single stat- I am willing to bet there is 4 who attest to the single keeping temps more stable for less fan time, cooling off quicker when hot. Warming up faster on cold mornings.
You can find @WarWagon accounts of it here and other forums long before I joined.

Run what you have if it works. If not-then play with it. But as hard as it is to find any rare part- I would say get the ones that Nate found that are in my signature.

Same components on my ‘94 and ‘99, except for single vs dual thermostat respectively. ‘94 runs at 195 to 200 a can easily hit 210 on a warm day. ‘99 runs at 187 and is mostly pegged there. It and rarely gets over 200 and you must be charging up a steep mountain grade in summer heat.

 

[SnowDrift]

Are you running the HO pump on both @Big T ?