taylor8907

Hey,

We just ordered a radiator for our ls swap into a 66 GTO
The radiator has the steam port being added, Just curious how all the steam ports tied together and where they are on the block and where they go exactly, I havent been able to find much on this. I know the front right of the block is at least one of the ports near the throttle body, but the throttle body itself also has a port, not sure if its vacuum or steam. Just not sure which ports need to be tied together and back into the radiator steam port.

Thanks in advance
-Allan

scooter77

This is the Kurt Urban Performance kit on my 4.8
Im gonna be running a degas (surge) tank on my car because my rad is lower then my heads.

G-Body

iTrader: (4)

How they are tied together depends on the year of the motor. There are 4 possible steam ports on the motor, one at the front and back of each head near the corners of the valley cover. On most truck motors the back 2 ports have blockoff plates from the factory. The front 2 have a crossover between them and IIRC the drivers side of the crossover has a nipple on it. That nipple is connected to the throttle body and then from the other side of the TB it goes out to the radiator. Some people will bypass the TB and go directly from the port on the crossover to the radiator.

scooter77

im gonna block off the throttle body port but would highly recommend running a surge tank. 2% air means 8% less cooling but 4% air means 32% less cooling i think it was. that was some statistics a cooling systems engineer posted on here i found awhile ago.

Russ K

iTrader: (1)

Just install the GM rear block offs. Then just have one 1/4" hose from the front cross over to the steam port of the rad. And if not driven in extreme low temps, then you can by-pass the the throttle body.

Note than the LS3 has the rear steam ports blocked off (no bolt on block offs). And my 418 is 525 rwhp, and still have the stock 2001 LS6 bock offs.

And as mentioned, a surge tank is a must. I'm going to adapt an early 3rd Gen F-body coolant tank for the LS3 swap into a 1968 Chevelle that I'm doing for a long time friend at my shop. And will try to adapt the washer tank from the Camaro as well. The stock washer tank had to be removed to make room for the Airaid cold air intake kit

Russ Kemp

taylor8907

Okay, I think I can sort out the steam ports now, Thanks everyone. Regarding the surge tank, Where in the system is that hooked up? between the steam ports on the heads and the radiator?