Mercier

iTrader: (15)

Hi guys,

I am finishing this thing up and noticed that I did not get any steam vent pieces on the 2005 LS2. Factory 243s and will be running a late-model TBSS-style truck intake if that matters. It appears to have block-offs on the rear two holes and nothing on the front. My 200-ish LM7 had a pipe setup that hit all four holes.

Would one of you be kind enough to compare the two setups for me and give me a recommendation? The LM7 setup is here and free bit I don't mind hitting the junk yard or dealer this weekend to get the "right" thing if I would be better off. Also, if I went the LM7 route, can I find the little metal/rubber gaskets at a parts store or is that a dealer item?

Thanks ahead of time for you time and help.

Project GatTagO

iTrader: (7)

There is a huge debate about this topic. However, if this is going to be a relatively mild engine, I see no reason to go with a 4-point system.

Andrew

Mercier

iTrader: (15)

Stock for now. Probably cam in the semi-near future but keep the 243s stock until next year. Does the LS2 come with a smaller piece that only hits the two front ports? If I already have the 5.3(4-corner) setup, should I use that instead?

Thanks.

Mercier

iTrader: (15)

And where can I get the gaskets for the steam vents? Dealership only?

Thanks.

txcarbuilder

If your engine is installed with the front higher you will probably be all right with just the front ones. If the engine is level or down on the front you should use all four.

Mercier

iTrader: (15)

Understood. Any downside to running all 4? That is the only actual steam piping I have currently. I would have to purchase the 2-up version.

Found the gaskets in stock at O'Reilly:

http://www.oreillyauto.com/site/c/de...&keyword=56390

Thanks!

Envy

Napa usually has them in stock as well, they carry their own in-house brand rather than the Dorman kit.

Mercier

iTrader: (15)

Can anyone tell me if there is a downside to running all 4 steam vents?

Thanks.

markbsae

There is no downside other than 4 places to leak instead of two. The system keeps you from building up air pockets in the heads and the bleed just allows coolant to flow and push the air (steam at +212 degrees) a path to escape to the radiator. Most run a two port system and the back are blocked off simply because the heads are symmetrical. Not sure the reasoning behind running all four.

Mercier

iTrader: (15)

Gotcha. I didn't think so but the front if angled this way or rear if angled that way kinda threw me off. I only have the 4-up steam piping from my early LM7 that just came out so I'll run that. I guess GM was still learning in the early motors and hooked up all 4. Thanks for the confirmation!

Envy

There is no downside to running a 2 port over a 4 port, nor are there less places to leak as you still have to deal the block offs. I've bought 2 5.3s, and both came with 2 ports, I've gone to the junk yard and pulled a 4 port from a 5.3, just because I was sure if I could get everything level, and just liked the idea.

RonSSNova

iTrader: (3)

If you can find the 4 port, use it.
To me it just makes sense.

It won't leak.

Mercier

iTrader: (15)

I also would have thought the 4-ports would be desirable. Just makes too much sense.

Now I need to find another 4-port so I can put this LM7 back together to sell it..any idea which vehicles had 4 vs. 2(or any other number)?

Thanks for the input, guys.

fieroguru

iTrader: (1)

GM installed the LS4 sideways and level, but only put the steam vents on the accessory end and capped the bell housing side.

When I did my swap, I converted it to the 4 corner system.

Mercier

iTrader: (15)

fieroguru - your car sounds like a beast. I'd like to see some pics. Especially engine clearance and transmission/transaxle setup.

ls1nova71

iTrader: (4)

The only downside to the 4 port is they won't fit under an LS6 intake. LS1s have more room under the intake, so they fit. When they switched to the flat floor LS6 intake, they started only using the front two. You can take a dremel or file and make grooves in the webbing on the underside of the intake to make them fit however. Of course you probably won't have an issue with a truck intake, so I would use what you already have.

Noahf

there was a thread on yellowbullet about this.

as ls1nova pointed out, the 4 port system does not fit under the ls6 intake which is when they started blocking the back ports and just using the front 2. Users on YB thought there was some relation between these blocked ports and the increase in cases of the #7 cylinder cracking in the ls6.

I decided to run all 4 on my swap. Alot of fluid flows between these ports.

Mercier

iTrader: (15)

Got it. Finally a reason for 2 vs. 4(or 4 vs. 2) I will stick with my 4 and find another for the LM7.

Thanks for the info!