LS Steam Ports - Block or Cross Over?

wesinls

wesinls

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Reading multiple opinions about this - curious what others are doing ...fwiw - I'm referring to these:
image.png

vs:
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Use them. There’s no way for air to escape the top corners of the cylinder head otherwise. GM spent profit on them, they’re important. 

 
The ones in the back of the head do nothing, All the new motors do not even have the provisions for the head gaskets, 

The way the block are machined the pumps sits lower than the tallest part of the motor, so in that small pocket air can be trapped, then big enough pocket it can add some cavitation 

We also make a full kit, Made in America by a board member that has a Haas, 

 
Mine are blocked.

Came back from engine builder like that after rebuild.  

 
J Alper said:
The ones in the back of the head do nothing, All the new motors do not even have the provisions for the head gaskets, 

The way the block are machined the pumps sits lower than the tallest part of the motor, so in that small pocket air can be trapped, then big enough pocket it can add some cavitation 

We also make a full kit, Made in America by a board member that has a Haas, 
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This feller?

https://www.alpermotorsports.com/index.php?l=product_detail&p=169

lincster said:
Mine are blocked.

Came back from engine builder like that after rebuild.  
Click to expand...
Best thing would be to periodically bleed them or get a kit to add them back. Any air bubbles from localized boiling in the heads will be trapped there. Head cooling is important for detonation. 

 
My friends Funco has what you show in the pic. Just a crossover tube with no breather to the expansion tank. Several times we had to stop due to an overheated head issue. Both times we had to crack the crossover tube bolt and let it breath out the steam. It was messy and a PITA. I have the stock style crossover with a steam tube that goes to the expansion tank on my LS swap I am doing.

 
Funco4JM said:
My friends Funco has what you show in the pic. Just a crossover tube with no breather to the expansion tank. Several times we had to stop due to an overheated head issue. Both times we had to crack the crossover tube bolt and let it breath out the steam. It was messy and a PITA. I have the stock style crossover with a steam tube that goes to the expansion tank on my LS swap I am doing.
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Same car, same problem, same solution, are you my friend??

After "burping" 2-3 times the overheating problem was gone.  No big deal.

 
danwalker said:
Same car, same problem, same solution, are you my friend??

After "burping" 2-3 times the overheating problem was gone.  No big deal.
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No big deal, just might have a hot spot in the cylinder, GM spent a lot of time and money on this design, so i would not take it lightly 

 
J Alper said:
Correct Designed by KRC, we use a cross over and a T, will post a pic, we run them back into the water pump on the return side, 
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Suction is sufficient there to pull the bubbles I take it? Was planning on running mine back to the radiator (already a fitting there). 

 
Rears blocked, fronts have the crossover with a breather going to catch can. Car runs at 170 degrees, never had an issue with hot cylinders

 
J Alper said:
Correct Designed by KRC, we use a cross over and a T, will post a pic, we run them back into the water pump on the return side, 
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Ty, just purchased a set!  

 
Steam.png

Picture instead of words.  Circled with arrow is why you need the steam port: the water pump outlet is lower than the coolant in the head and will trap air bubbles there.  If you have block offs and didn't crack them when you filled the coolant system or haven't in quite some time, chances are very high there's air trapped in there and you're leaving money on the table not cooling your cylinder heads.  If there's blockoffs and you're overheating, this would be the first place I'd check.

 
Bobalos said:
one other comment to throw on top of @Rockwood's comments.......... 

there is a very distinct difference between a "catch can" and a "surge tank". 
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Yep. Under no circumstances should the steam port go to a catch can.  Pressurized side of the system only, otherwise you'll have a bit of a mess on your hands... :biggrin:

 
Just checked mine, blocked in the rear and the fronts are already in a T from factory so I just ran it to the top of the radiator. My radiator had a barbed fitting there so it worked out. 

 
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