OK, LT1 swappers and TGO cooling experts. I could post this on the cooling board but I thought the TPI board was more suitable.

OK, so we all know that this swap needs a remote mount thermostat. My question is on routing the lines. I have two options, I believe. One is run the lines out of the passenger head into the tstat housing, driver head to tstat housing, heater core to tstat housing. And the big hose back to the radiator. Is this correct?

Now, to eliminate lines and complexity, I have a new option that possibly has an intrinsic flaw that I am not aware of. Run the passenger head line to the heater core and the line that comes out of the heater core will return the fluid to the small passenger radiator return. Then the drivers side head will go to the remote tstat housing and back into the radiator. Now, people will say, "BS, uneven cooling." I say that the coolant that comes out of the heads has already done its cooling job on the engine and is being returned to the radiator to lose heat and repeat the process. Is this a flawed conception?? Also, I know that the heat from the drivers head will dictate thermostat opening rate but I assume that the heads are heated evenly. Suggestions?????

 

Your first statement concerning routing is correct, I will post a picture later today to show the suggested hose routing.

The second idea is flawed. You may have forgot about the valve that cuts off the coolant to the heater core when the A/C is on, it could cut off the coolant from the passenger side head unless routed differantly.

 

Yeah. Me like pictures.

 

 

I have removed the valve previously. I have the heater core outlet plumbed directly into the radiator inlet. So, can anyone really disprove the the second alternative??


John, that pic didn't work.

 

Picture works for me.....

 

And me

 

The bypass valve is a non-issue. Some cars never came with one. The ones that did bypass the flow directly to the radiator, skipping the heater core. It does not block coolant flow, it diverts it.

That would be me. Look at it this way, when the thermostat is fully open, nothing wrong with your statement. What about when its not all the way open? There are many more times than you think that this happens. In this case, the driver head is in essence blocked off from coolant flow, and the passenger head is really seeing full bypass of the thermostat. Uneven? You betcha!

 

Madmax,

I that is exactly what I was looking for. I am ashamed I didn't think of that. Anyhow, I have seen those valves that actually block flow to the heater core, but not on a thirdgen. Thanks

 

Hey BIRD, I use Netscape 4.79. The picture don't work for me either. If you want to get radical, you could mount a remote t'stat housing on the passenger side as well to use heater core return.

 

Have you tried the link instead to get the picture to work?

http://www.lt1intake.com/images/Hose%20Routing.jpg

 

John, no pic for me either. I tried copying the imgage location and the "%20" was missing from it. Your link works though.

As for coolant routing, so far so good on mine. I'm using the back port on the drivers-side head. We've had some pretty hot days with heavy traffic, no problems yet.

Two thermostats probably not a good idea, unless they are perfectly calibrated for opening rate and temperature.

 

The heater hose return is in the right side of the radiator.
The coolant from your right head will go to the heater core then
to the RIGHT side of the radiator where it will NOT go through
the cooling tubes of the radiator because it will be immediatly
pulled back out by the water pump and circulated back through
the block.

The left side of the engine will work as normal because the
coolant will flow to the LEFT side of the radiator where it WILL
go through the cooling tubes of the radiator before it is pulled
back out and circulated through the block.

Don't do it, you willl cook the RH side of the engine. The only way
to do it is the way John has it diagramed. You will need to be sure
the heater hose is constantly moving coolant from the engine to
the radiator so the thermostat can heat up and open properly.

 

Swap, I do not think I will "cook" the right side of the engine. The entire engine would just see hotter coolant. Anyhow, thanks guys.

 

As you should already know, the left and right banks are seperate
and are only joined by the waterpump and intake manifold.
When you strap on an LT1 manifold you eliminate the crossover
provided by the intake and create two seperate cooling situations

If the coolant from the right side is never introduced to the upper
radiator hose it will not go through the radiator and cool down.
Since the heater return nipple is on the outlet side of the radiator,
the coolant will be in a continuouse loop from the head to the
heater core to the radiator tank to the block to the head and so
on and so on without ever being cooled by the radiator tubes.

The right side will overheat.

The only time the loop will be broken is when the thermostat
opens and coolant from the radiator is reintroduced into the
water pump. But when the thermostat closes and flow stops in
the left side of the engine the loop will begin again in the right
side.

Another point is that if you don't plumb the heater hose from the
remote thermostat housing there will be no HOT coolant the triger
the thermostat to open.

 

That can easily be fixed with a different radiator. All you have to do is have a blockoff plate put in the side where the heater hose inlet is, problem solved.

 

The system must be plumbed the way John has shown or the
engine will not cool properly.

 

I meant if he ran 2 thermostats, then you could just hook up one to the heater core return in the radiator if the radiator has a plate installed in the RH tank to block flow from going straight through on that side.

I dont really like the idea of 2 thermostats though. Just more to go wrong IMO.

 

You guys are trying to overcomplicate the issue here.

Bird wanted to know if his theory was flawed, and it is.
Each side of the engine must come to the remote thermostat
housing. This will ensure both sides will cool properly. There
must also be a line from the thermostat housing to the heater
core and from the heater core to the RH tank of the radiator.

When the thermostat is closed, coolant will flow from both sides
of the engine to the thermostat only because a portion of the
coolant will be pushed through the heater core and back to the
radiator which will ensure hot coolant is always present at the
thermostat.

If there is no line from the themostat housing to the heater core
the thermostat WILL NEVER OPEN. There will be no way for the
hot coolant to get to the thermostat to warm it up.

 

Since I live in Texas I got rid of all the heater core plumbing and capped the 3/4" inlet on top of the radiator. In theory I guess I don't have as much capacity. I didn't give it much thought when I hooked everything up, but it seems to be cooling fine the little bit I've driven it.

 

Well, I see your point about needing a bypass which is what you are referring to with the heater core line. You'd need one both sides. Like I said, I dont like the idea of using 2 thermostats.

Not to nitpick, but the thermostat would still have no choice but to open at some point in time, the only question is how hot the coolant in the block would be at that time. Water conducts heat through itself fairly well though.

 

Yes the thermostat would open eventualy, sooner if it were
located closer to the engine with shorter lines. But, the engine
would be have to be pretty hot to get it to open. I would not
want to wait for convection to transfer enough heat to open
the thermostat. You could drill a few 1/8" holes in the thermostat
to keep some coolant moving I guess.

I talked with John and he is going to put the water outlets in
the rear of the intake when I order mine. I will keep everything
short and sweet and tucked back low on the firewall out of sight.

I don't know how much room a third gen has back there but my
Jag has all kinds of room to play with. I can even take out all of
the bellhousing bolts with a ratchet from the top side.

 

Has anyone seen the picture yet. I reposted it and it should clear
up any confusion.