VLS1

Guys I am wondering how everyone is running these on their carb setups? Just vented at the front and blocked at rear, or running all four to one pipe etc.

TIA

tim burks

im using the factory crossover and my radiator has a place for the vent line

TXsilverado

iTrader: (18)

I have all 4 connected and running to a jtr steam vent in the radiator hose

TXsilverado

iTrader: (18)

Like this but it now has the early camaro crossover that connects all 4 vents.

Horsepwraddict

iTrader: (12)

I run the back two blocked off and I welded a nipple to the outlet on the water pump for the front. Im using the stock front crossover.

Doug G

I'm running the TrickFlow 4-corner kit....but you could do the same with a tap, some AN fittings, and a few feet of braided line.
Oh, and I tee'd into the thermostat housing.

homemade87

Here's what I did to mine . The water passing the fitting is going straight into the hose anyway . I did not see much need to do more . Has worked flawless .

Pop N Wood

iTrader: (1)

Funny, I did mine just like homemade87. I have an LS2 with only the front two plumbed and the back two blocked off.

lblevins

iTrader: (4)

my ls3 heads have the rears plugged from the factory and I have the front 2 plugged same way I had my 243 heads. All plugged and never had a problem.

homemade87

I would suggest plumbing the front in . Generally you can get by without the rears because the head rises in the front and the steam/air will move to the front of the head at the highest point . These engines are designed this way can not purge the air on there own . Think of it this way . If you hold a bucket upside down under water where can the air go unless you remove it some way . Thats what the steam lines do .

Chances are you have some hot spots in the head and could cause detonation and damage and you do not even realize it until its to late.

lblevins

iTrader: (4)

Well I guess I can throw it on for good measure. My last engine made it thru almost 30k miles and lots of road trips and probably 100 1/4 mile passes. I sold it to my buddy and it's been in his truck ever since. Guess I get really lucky.

VLS1

Great info thanks all. I was planning on only using front vent pipe, and jacking front end when filling/bleeding cooling system which may also help matters.

sbmalibu

Has anyone ever tried to pull out the plugs in the back of the newer heads?

3pedals

iTrader: (3)

yes, just use a drift and knock em out.

WEIGHTMAN

off hand what size an would fit

Doug G

You would need to tap it 1/8" NPT and then get the pipe to AN fittings. Most likely need to drill first, then tap.
-2 or -4 should work fine.

Pop N Wood

iTrader: (1)

The rear plugs bolt in just like the front ones. That is how you get plugs to block off the front vents, they first introduced them with the LS6

The vents aren't absolutely needed, lots of guys block all 4 vents. You just need to make sure you purge all the air every time you fill the coolant system. Steam vents are a misnomer, they are there to vent the air on the initial fill. If there is any steam in the head then you have other issues. Lots of opinion on this topic. Some guys swear not venting all 4 corners means it is only a matter of time before you smoke a head.

WE TODD DID

iTrader: (2)

Made something up here

Doug G

Looks good....better than the Trickflow one

WEIGHTMAN

so couldnt you just put some bleeders on the front then