Engine swapped cooling system question
11-08-2018, 05:14 PM
#21
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Thanks! The radiator was re-cored by a recommended shop. Tanks and necks are original. I do have the coolant funnel with adapters. I didn’t want to risk messing with trying to braze keepers on the necks for fear that the radiator shop might void any kind of warranty on their work. Today I switch over from worm gear clamps to T post style hose clamps and doubled up on the radiator side. I still think I need to run a cooler T-stat to try and get closer to a 180’ish op temp. O’Reillys sent me a 160 degree t-stat that was supposed to work but it was to big in diameter (I’m thinking it was meant for a SBC). Anyone have a lead on a 160 t-stat for an ls?
11-08-2018, 05:26 PM
#22
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Should be no need whatsoever to run T-bolt style clamps, and in many cases the wrong ones are just pure ***** for small diameter hoses.
You should be bursting hoses before a lack of a bead on a pipe that diameter with regular good quality worm drive clips are even the slightest concern
You should be bursting hoses before a lack of a bead on a pipe that diameter with regular good quality worm drive clips are even the slightest concern
11-08-2018, 07:07 PM
#23
T-stat Thanks! The radiator was re-cored by a recommended shop. Tanks and necks are original. I do have the coolant funnel with adapters. I didn’t want to risk messing with trying to braze keepers on the necks for fear that the radiator shop might void any kind of warranty on their work. Today I switch over from worm gear clamps to T post style hose clamps and doubled up on the radiator side. I still think I need to run a cooler T-stat to try and get closer to a 180’ish op temp. O’Reillys sent me a 160 degree t-stat that was supposed to work but it was to big in diameter (I’m thinking it was meant for a SBC). Anyone have a lead on a 160 t-stat for an ls?
What is the maximum running time you have on this set up? Highest temp it reached during the test run?
11-08-2018, 11:53 PM
#25
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On the first couple of warm up cycles the temp never got above 205 before I plugged the fan up (not wired in yet so i just run it of a jump box) then it drops to about 190-195. I really wanted a fan to “fit” the original shroud better but I couldnt find an electric one big enough. Then I thought about making my own and I decided it wouldn’t have looked as good as the original. The radiator is very thirsty holding at least 3+ gallons itself so I figured heat transfer wouldn’t be an issue. Again, it’s not that I’m worried about over heating, I’m worried about to high of pressure for the radiator. Lower temp=lower pressure. I honestly don’t think I had that upper hose on there tight enough the first time. Now with double t-bolt clamps I’m fairly confident it won’t pop again.
11-09-2018, 01:02 AM
#26
LS engines are generally not hard to cool, so with as big of a radiator as you have I would think it would be fine. My car with a stock thermostat and the fan temps changed to come on a little sooner will run 195 all day long no matter the outside temperature. If you're really concerned about the pressure, which i feel isn't really going to be an issue, just put on a lower pound radiator cap, it doesn't get much easier than that.
11-09-2018, 04:43 AM
#27
Obviously the engine goes out hose is going to be hotter than the goes in. The lower hose is cold because the radiator is cooling it.
Run that thing!!
11-09-2018, 09:04 PM
#28
I think your good to go On the first couple of warm up cycles the temp never got above 205 before I plugged the fan up (not wired in yet so i just run it of a jump box) then it drops to about 190-195. I really wanted a fan to “fit” the original shroud better but I couldnt find an electric one big enough. Then I thought about making my own and I decided it wouldn’t have looked as good as the original. The radiator is very thirsty holding at least 3+ gallons itself so I figured heat transfer wouldn’t be an issue. Again, it’s not that I’m worried about over heating, I’m worried about to high of pressure for the radiator. Lower temp=lower pressure. I honestly don’t think I had that upper hose on there tight enough the first time. Now with double t-bolt clamps I’m fairly confident it won’t pop again.
Now I understand what your trying to do a bit better. Yes, low temp = lower pressure. With your doubled up T-clamps I really don't see you having anymore problems and as you probably already know the temps your stating are well within specification. Geez, that is one big radiator at 3 gallons, heat transfer with your setup should never be a problem. I suspect they install those big radiators as to allow the engine and pto to run the pump stationary while sitting on the scene pumping for countless hours. Those were the good days for me and I still miss them even though I was in the service for 35 years. Best of luck on your build, it's really a nice ride.
03-23-2019, 08:26 PM
#33
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Under her own power 
Wiring is now 100% done. There a still a couple of little things left to take care of but I took her around the block for her maiden voyage the other day.
03-23-2019, 09:06 PM
#34
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That truck looks GOOD! NICE job!
03-26-2019, 10:57 AM
#36
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That's fantastic! What did it take to mate the engine to the original (I assume) transmission? Any videos of it running / driving that you could share?
[This thread really needs a better thread title, "cooling system question" isn't going to give it the attention it deserves!]
[This thread really needs a better thread title, "cooling system question" isn't going to give it the attention it deserves!]
03-27-2019, 08:37 PM
#37
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Under her own power I had a short video of me driving the ‘45 around today but it wouldn’t let me up load it. Drove it around the area for about 45 minutes with no issues. Running about 180 on the temp gauge which is what I was hoping for. Pulled the truck into the shop and turned the truck off. Before I could even step out of the cab, pop, there goes the upper radiator hose again. By the way it sounded like it just slipped off and not blew off I’m guessing pressure wasn’t a problem. Guess I’ll be trying g to figure out how to get a bead on that upper neck.
03-27-2019, 08:54 PM
#38
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That's fantastic! What did it take to mate the engine to the original (I assume) transmission? Any videos of it running / driving that you could share?
[This thread really needs a better thread title, "cooling system question" isn't going to give it the attention it deserves!]
[This thread really needs a better thread title, "cooling system question" isn't going to give it the attention it deserves!]
03-27-2019, 08:59 PM
#39
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The TH400 is ideal for what it's doing. A largeish truck that does not need an OD gear most times.