Hi All,
I am new to the site and currently undergoing a 55 chevy restoration with a new LS3 Corvette engine and 4L60e transmissions.

I just installed an aftermaket rad that has two fittings for the transmission lines. Since I will be using a frame mounted tranny cooler i want to use one of the rad fittings as a steam fitting going to the engine.

One fitting is near the top of the rad and one fitting is near the bottom. Does it matter which fitting I use? i.e does the steam fitting have to be high or at the top location? The bottom hole has betting routing access to the engine so I would prefer to use it.

Thank you.
Gobs

 

I can's say if it matters but the stock location is to the top of the rad. If your motor doesn't have it already you could think about adding the rear fittings to the heads. I didn't do mine and wish I did just for peace of mind.

 

That will not work. This is how the steam fittings work.

 

I am a bit confused. I am really new to the LS motors.

You state that the steam fitting should be connected to the toip of the radiator like the factory application but not the in either of the two rad locations originally designed for the auto transimission lines? What would be the difference as one is near the top of the rad?

Would I be able to attached the steam tube from the motor to a rad overflow tube where there is no pressure?

Lorne

 

The transmission cooler is seperate from the radiator. DO NOT connect the steam line to one of those fittings. If you can't connect it to the actual radiator, then tee it into the top radiator hose, or drill and tap the top of the water pump and connect it there.

 

The internal transmission cooler connections are not open to the coolant. It is the same as an external cooler (just a loop) except it is inside the tank and surrounded by coolant. Think of a tube going into the tank and coming out the other connection, that is all the cooler is, otherwise you would have trans fluid and coolant mixing. The steam vent needs to return to the coolant system, otherwise you don't remove steam/air. I use a surge tank with a vent connection to continually remove the air. Here is a link with several different ways to vent a LS.
http://www.pirate4x4.com/tech/billav...CoolingSystems

 

yes mcss is right there the tranny cooler in the radiator is a completely different system not and option!!!!you can also put it in the top of the water pump output,or the upper radiator hose with a tee or in the top of the radiator theres your options. you should do more research before you dive into this swap there is alot more details that your going to need to know. in any case good luck with your swap.

 

Since you have a radiator with a AT Fluid cooler in it, it would be advisable for a driver, to connect the transmission cooler lines to the radiator.A air to air heat exchanger on the frame WILL NOT properly cool the transmission near as well as a cooler inside the radiator.
DDD

 

I'm not following you on this... why would think that outside air (max 110°) would not cool as well as water that is on average 150-200°??

 

If you take a piece of steel, heat it up to 300 degrees.Wave it around in the air until it gets to 125 and see how long that takes.Take that same piece of steel and imerse it in water and compare. The heat is given off into water much better that air to air.Ford tried that in 99-2000 super duty trucks with auto transmissions so they could save a few bucks.After buying thousands of new transmissions under warranty, Ford issued a tech bulliten updating the radiator to include a transmission cooler.I see bypassed in tank coolers all of the time.....and they are here because whoever did their trans, and bypassed the in tank cooler, set their customer up for failure.
In a car you can better get away with it.On nice days it will most likely operate at a safe temp.When it is hot outside, the cooler wont be able to give off enough heat to keep the trans fluid cool.When it is 110 outside the trans fluid will very hot.The overall hotter operating tempurture will break down the additive package in the ATF and will shorten the lifespan of the transmission.The cooler it runs, the longer it will last.On a show car the lines look ugly under the hood, but a driver should run them.
DDD

 

Back to the original question, thought I'd give my 2 cents and get back to the question...

GM designed the Steam and cooling sysetm.. so you would think GM had put some research into this and where the best place would be to put it. So if it is good enough for GM, it is good for me...! This would be routing (Mostly) into the Radiator tank just below the filler neck.

If you have a radiator with a port/bung, not the Trans lines or the overflow port.. you can use it.. many aftermark radiators come with the extra port.

If you have a metal tank (steel or alum).. you can get someone to weld, braze or solder a bung into the tank. SOL if plastic...

If not then the alternative would be to route to the following :
1) tap into the water pump,
2) use a tee and route into the Heater core line or the radaitor hose. Jags that run has many options for Tee's, but you should find other places would have some also.

 

One final point to make is that the steam fitting at the radiator needs to be at a higher point than the exit from the block to prevent an air pocket from forming in the engine.

 

Question the that note: How come it works when you tap the water pump (lower than all steam fittings)?

 

My best guess would be that this point is pressurized by the water pump and acts as a bypass since it is prior to the thermostat, similar to the bypass in a SBC under the lower water pump bolt on the pass side.

 

The specific heat of water is roughly four times that of air, so as long as the trans doesn't need to be cooled to less than that 150-200 range cooling it with water should be more effective (though this is a simplification and overlooks many other factors of course).

Rather than mess with tapping the water pump I just grabbed one of these connector pieces and stuck the steam fitting in it. The connection also adds a little bit of versatility when it comes to finding new radiator hoses, which I seem to do often as I swap motor after motor.

 

Here's my take on them and it works. I was able to modify a truck vent line for use in the front and rear. I think it is important to keep a rear crossover rather than use block offs. Had to disconnect the upper hose and vent line at waterpump when I first filled the system. Other than that detail I have not had any issues.

 

I plumbed mine into a t-fitting I put in the heater hose that the water pump pulls from. That way, any steam that rises to the top gets pulled into the water system, regardless of whether or not the thermostat is allowing circulation throught the radiator.