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LT1 engine, JTR radiator and heater hook up.


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Ok there are way too many water lines on this engine and not enough places to put them. There are three small hose fittings and two large ones on the LT1 water pump.

LT1WaterPumpFitings.jpg

I am eliminating the throttle body pass through, just plugged the input and output on the throttle body.

From the manual it looks like the heater hoses go to #1 and #2 on the water pump. I have the "T" fitting from JTR but I'm still one connection short. If the steam hose from the heads goes to the "T" fitting on the lower radiator hose where does #3 from the water pump hook up? I am obviously missing something critical here.

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Corvette water pumps don't have fitting #3.

Hose # 3 goes to the oil cooler (on Camaro's with the oil cooler) or it goes into the inlet side of the Camaro radiator.

You can plug the fitting or tee it into the upper hose.

The best way to plug the fitting is to remove the fitting, tap it with a 1/2 npt (national pipe plug), and use a 1/2 npt plug.

To remove the fitting from the water pump, twist and pull on it. I normally use a large screwdriver and insert it into the fitting and work it loose.

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Corvette water pumps don't have fitting #3.

Hose # 3 goes to the oil cooler (on Camaro's with the oil cooler) or it goes into the inlet side of the Camaro radiator.

You can plug the fitting or tee it into the upper hose.

The best way to plug the fitting is to remove the fitting, tap it with a 1/2 npt (national pipe plug), and use a 1/2 npt plug.

To remove the fitting from the water pump, twist and pull on it. I normally use a large screwdriver and insert it into the fitting and work it loose.

 

Ok that solves that. Figures, 3 different pumps and I get the wrong one, LOL No way am I removing everything again to change that.

Scary at this stage of the game to attempt pulling that out and tapping it without removing it from the engine! We may have to work around it, maybe another "T" from JTR would be the way to go.

lt1_water_pumps.jpg

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I plugged my #3 similar to the way Mike described. I removed the fitting and filled the hole with a rubber expandable freeze plug that I got from Pep Boys. The rubber plug is sandwiched between metal plates with a metal stud that goes from the back plate through the front one. When you tighten the nut onto the stud the rubber plug expands to ensure a good leak free seal.

 

Just another option for you to think about, I know that threading the opening and installing a threaded plug would probably be the best solution.

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I plugged my #3 similar to the way Mike described. I removed the fitting and filled the hole with a rubber expandable freeze plug that I got from Pep Boys. The rubber plug is sandwiched between metal plates with a metal stud that goes from the back plate through the front one. When you tighten the nut onto the stud the rubber plug expands to ensure a good leak free seal.

 

Just another option for you to think about, I know that threading the opening and installing a threaded plug would probably be the best solution.

 

That's a thought, thanks. I was looking all over your website to see where you ran that hose and of course couldn't find it, LOL.

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I went the tapping route, but them I had the front of the motor off. I used a prybar to wiggle the fitting out (took some work too) and then had the hole tapped for a 1/2" NPT fitting.

 

No probs!

 

Bryan

 

That would be best but I really don't want to pull all that stuff off again.

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Now that was not the easiest thing I've ever done, I actuallly broke a good sweat. I managed to get the #3 fitting out of the water pump without breaking anything, LOL. Now off to the parts store for the freeze plug, thanks for that tip Bartman.

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  • 4 months later...

The #3 fitting everybody is talking about is the one pointing down in the shoebox photo of the F body water pump posted by Deja correct?

So that leaves the upper radiator hose which gets the JTR "T" fitting inline from the top radiator outlet on the drivers side and the bottom radiator hose passenger side. The rear steam line connects to this tee?

The heater hoses are the other two connections on the water pump with the stock F body steam vent and finally an overflow hose from the radiator to the stock Z overflow bottle? the other steam vent is on the thermostat upper radiator connection already.

The throttle body connections are just capped off?

Just seeing if I got this right.

 

Thanks,

Greg

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  • 1 year later...

Greg, I know these posts are a little old but I am still confused. The pipe that everyone is saying to plug is hooked up to my oil cooler system. 93 Trans Am's had that and I still have another hose about a 1/2" coming out from the bottom of the TB plus the top hoses in the TB, I seem to have only one steam vent hose that is tee'd in the rear from both heads that has to plug in somewhere I believe to the lower Rad Hose with a tee. Heater hoses, I know one plugs into the pipe on the left, the 5/8" one at the bottom and there is smaller 1/2" hose on the left TOP that is what? the other heater hose. Normally the heater hoses would be the same size. Where does that lower TB hose go? By now have you found a link to a complete hose diagram that I might go to. There is too many hoses on these engines. The return oil cooler line has to go some where, I suppose to the Upper rad hose since there is no port on the JTR radiator tank for it. Thanks

Larry

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I don't have the oil cooler so I am not sure I can help you with that.

As for the 2 hose connections on the throttle body I just capped them, they are not needed, they are used to warm the throttle body up for cold winter driving which I don't do.

The steam line coming from the rear of the motor needs to be run into the bottom radiator hose with a "T" fitting that is available from JTR.

So to confuse you and probably myself one more time there is another thread here:

http://forums.hybridz.org/showthread.php?t=134583

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Greg is right about the TB lines, you don't need them. The heater hoses are NOT the same size on the LT1, you can get a reducer at any parts store. I don't have an oil cooler either But this might give you the idea of how its hooked up on an F-body. Looks like it goes to a lower radiator fitting.

 

oil_cooler.jpg

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Greg I undestand about capping off the TB lines but I have a third line coming out of the base of the TB about 3/8". Don't have a clue about thus one yet.

 

DEJA. The oil cooler line is on the drivers side. It looks like it is suppose to go into the radiator tank but JTR's tanks don't have a available fitting. So I guess it will have to tee into the upper radiator hose but unfortunately JTR says to connect the head vent tube to the same hose so that means another tee unless I can make one with two connections. I was thinking about venting the heads into the lower hose Would that work? I was also thinking that maybe I could have a fitting installed into the passenger tank for the vent but JTR's tanks arre plastic, Can this be done?

Larry

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From the picture it appears as though the oil cooler is fed from the third line (driver's side connection) on the F-Body water pump and then the coolant returns to the bottom of the radiator. Hooking the return line from the cooler to the top radiator hose should work fine.

 

BTW: The steam vent line that normally passes through the TB should also be hooked to the top radiator hose. Hooking it to the bottom hose will inject hot steam from the engine into the cooled water coming from the radiator. Not sure this is such a good idea.

 

So the complete system should have the steam vent line and the oil cooler return line T-ed into the top radiator hose, the bottom radiator hose should not have either of these lines T-ed into it. The heater hoses should both be connected the the 2 connections at the water pump the point toward the passenger side of the car.

 

That 3/8" line at the base of the TB is part of the PCV system.

 

Hope this helps.

 

Wheelman

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Wheelman, Thanks. You see it like I do as far as hooking both the oil cooler and the head vent into the upper hose. I guess that would mean two tees unless you know a better way. It seems like it's getting a bit cluttered. As far as that 3/8" line. I just figured out tht the hose I was wondering about is the TB coolant line but on top of the TB on the passenger side there is another 3/8" line that looks like it has had fuel in it. I have the shop manual from Helms and pictures of the TB show this port but it doesn't say what it is. Any Ideas?

 

Maybe I can make a double tee for that rad hose. I got to learn to braise.

Since the vent has to connect to the upper hose on the opposite side of the engine, I don't see any reason not to run it through thee TB and do away with some of thet unsightely hose.

 

Thanks

Larry

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http://forums.hybridz.org/showthread.php?t=120554&highlight=steam

 

Wheelman, Thanks. You see it like I do as far as hooking both the oil cooler and the head vent into the upper hose. I guess that would mean two tees unless you know a better way. It seems like it's getting a bit cluttered. As far as that 3/8" line. I just figured out tht the hose I was wondering about is the TB coolant line but on top of the TB on the passenger side there is another 3/8" line that looks like it has had fuel in it. I have the shop manual from Helms and pictures of the TB show this port but it doesn't say what it is. Any Ideas?

 

Maybe I can make a double tee for that rad hose. I got to learn to braise.

Since the vent has to connect to the upper hose on the opposite side of the engine, I don't see any reason not to run it through thee TB and do away with some of thet unsightely hose.

 

Thanks

Larry

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The steam vent tube goes into the upper radiator hose.

The hose from the oil cooler goes into the lower radiator hose. If you put it in the upper radiator hose, the coolant will bypass the radiator, and the engine may overheat.

 

The thermostat housing in the LT1 is an inlet-sensing design, with full flow through the engine when the thermostat is closed. The coolant going to the oil cooler does not flow until the engine warms up. An older small block has a small bypass hole that allows a limited amount of coolant to flow through the engine when the thermostat is closed.

 

While many people think the reverse flow cooling is the most important aspect of the LT1, it is the inlet-sensing thermostat, and full-flow cooling (when the thermostat is closed) that makes the LT1 cooling system a modern design.

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The hose from the oil cooler goes into the lower radiator hose. If you put it in the upper radiator hose, the coolant will bypass the radiator, and the engine may overheat.

Mike,

I'm going to have to disagree with you here, the direction of flow from the engine to the radiator is through the upper radiator hose. If the oil cooler return line is connected to the upper radiator hose the coolant will not bypass the radiator, but if it's attached the lower radiator hose it will. That's why you don't want to attach the steam vent line to the lower hose, the coolant would end up bypassing the radiator.

 

This thread has a very detailed description of the coolant system of an LT1:

http://www.impalassforum.com/vBulletin/showthread.php?p=1978454

 

Wheelman

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Mike,

I'm going to have to disagree with you here, the direction of flow from the engine to the radiator is through the upper radiator hose. If the oil cooler return line is connected to the upper radiator hose the coolant will not bypass the radiator, but if it's attached the lower radiator hose it will. That's why you don't want to attach the steam vent line to the lower hose, the coolant would end up bypassing the radiator.

 

This thread has a very detailed description of the coolant system of an LT1:

http://www.impalassforum.com/vBulletin/showthread.php?p=1978454

 

Wheelman

 

 

Oops. My mistake. You are correct.

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