Jim85IROC

iTrader: (6)

Anybody running a rear-steam tube setup with a stock LS3 intake manifold? I'd like to connect the rear steam ports on my motor (LQ9 stroker, LS3 heads/intake), and would prefer the f-body style setup under the intake if it can be done, but I'll also consider external options if required.

1A Dan

iTrader: (9)

i went with a combination of ls3 and l92 front crossovers and just tied em together with some hose. not too pretty, but does the job. however, going with some an setups come spring time

Jim85IROC

iTrader: (6)

yeah, that seems like an option too. If I can bend up some hard line I could make it look decent, but having it under the intake would still be a lot cleaner. I'm going to have to look at my intake tonight and see if it's just a matter of grinding away some ribs like on the LS6 intake.

Doug G

I'm guessing the rears are blocked off from the factory ? (New to LSx)

Going to be doing a LY6 clone... Carbed.

Would love to do AN fittings and braided line...but $$$

bww3588

iTrader: (49)

my thought on this, if i cant make the LS1 style 4 corner steam tubes work under the LS3 intake, was just use 2 front steam tubes and connect them together using the existing PCV routing locations right up above the valve cover. the clips are already there so it would look somewhat factory. AN fittings would be nice, but again...the dollar factor.

Jim85IROC

iTrader: (6)

the more reading I'm doing, the more confused I'm getting about whether to use the 4 ports or just plug the back two. Ultimately, it seems that either is perfectly adequate for street use (what my car is primarily used for). I'm starting to think I'm just going to cap off the back two, and just figure out which front style suits my needs the best.

Mike454SS

iTrader: (4)

GM has been running with the rears capped since like 2001, and now with the LS3's the holes in the heads aren't even opened on the rear (so heads are actually unique left to right which they never were before...but minor machining can make them the same again)...I think running with just the fronts is fine. If you're running strictly water and not an antifreeze mix your boiling point is lower, and then you might need the rears to be sure you vent steam out and allow coolant in...but with a 50/50 mix on the street in your coolant, it shouldn't be an issue.

1lejohn

iTrader: (9)

My old stock 99 Ls1 4 hole tube assy. worked just fine on my combo. Running just water and wetter water. FWIW

Jim85IROC

iTrader: (6)

my LS3 heads had one part number and they have the holes on both ends.

1lejohn

iTrader: (9)

I would use all 4 its beter if your going to run the car hard. The stock LS1 tubing will work if you bend it a little. It won't on the Fast but will on the GM stuff.

Its like the old 400 small block that had steam holes drilled in the block and heads

PJV SLC

I have a new E-rod LS3 crate engine and the rear steam tube ports are blocked. Any idea how to open these up without taking off the heads? Would like to run all 4 ports, but not sure it is worth the trouble to have to pull off the heads and drill the plug. Attached is a close up that shows the plug. Any advice is most appreciated.

97badass

iTrader: (8)

It's just a welch style plug afaik...

GTMLS3

I just drilled the holes out, it is a thin plug, that seem to be pushed in. The heads were tapped to take the same cross over that is on the front ports.

Mike454SS

iTrader: (4)

Probably because the service part number is for either side of the engine. The OEM ones on LS3 cars are capped at the back, but not with caps that you can swap like you could with older stuff like an LS6.

bww3588

iTrader: (49)

my 0821's directly off a 2010 Camaro have all 4 ports open...

Jim85IROC

iTrader: (6)

I decided to plug the rears. If it's good enough for all the modified ls3s out there, it's good enough for my car.