tomz28

iTrader: (20)

I get that air will come out of a new engine. but if its block than what? All my info comes form a lot of doing,reading, and talking to some of the biggest guys in the business. So you can use the info or do what you want. As far as why GM blocks some and vents other couldn't tell I don't play with stock stuff lol if I can help it

Andy1

Wegner Automotive has them as well. $6.50 ea.
http://s41657.storefront-solutions.c...l.aspx?ID=3289
Andy1

Irish350

iTrader: (14)

looks like you still need hardware, but those are still by far the cheapest, good find andy.

And yeah, JJ, i think all the LSs come from the factory with just 2 ports vented, and the other 2 blocked, so you could do that again, but they put the ports in the heads for a reason right? For me its worth the extra up-to-50$ for the piece of mind that my #7 cyl isnt getting overheated trying to lift the head off.

the car came w a 78mm throttle body too, but that got changed

MeentSS02

iTrader: (11)

There are ports front and back so GM wouldn't have to have a separate left and right head. They probably only put vents on the front since in most applications, the engine sits at an angle with the front of the engine being the highest point in that system, so the air bubbles would naturally find their way there. Does this actually happen? That's what would be nice to know, and I don't have the equipment to find out.

Irish350

iTrader: (14)

I hear ya Steve.. There was a nascar-type team who was searching for an answer due to their detonation/high temp issues at the rear of the engine.. i think they gave up cause they solved the problem in another way, but that was as much tech ive seen thrown at it

MeentSS02

iTrader: (11)

You've found as much as I have on the issue then...regardless, when I eventually build a new engine, I'll tie the front and back steam ports together just to make sure. If I'm not mistaken, the front and back ports were tied together when GM was still using the LS1 intakes...the LS6 intake had a dropped floor, so they could no longer run the tubes under the manifold, and I guess they just said "to hell with them" and never looked back.

71ANTICARB

iTrader: (23)

After thinking bout this for awhile I have another question why do you want to run the -4 line anyways. There isn't a flow issue here they are just steam ports wouldn't the factory lines be sufficient.

And as far as blocking the rear/lowest ports, GM has been using the LS1 based engine going on 14yrs now producing millions of variations of the engine. I think that if they need the rear of the head to be vented they would have done so. They have budgets that make NASCAR teams look like pocket change. And when they went to the ls6 intake as was said they got rid of the rear ports due to the drop floor however if they would have been needed I'm sure they cod have found a way around that.

Sorry for the ramble I'm bout half asleep I actually woke up from a dream about this.

-TheBandit-

iTrader: (1)

Have you thought about just modifying the stock crossover tube end-fittings for your desired port configuration? TIG welding some aluminum AN fittings shouldn't be too hard for you J.J. You could drill out the rear block fittings if you wanted all four.

MeentSS02

iTrader: (11)

Although GM has a fairly large budget, when you are talking about millions of variants of an engine being produced per year, even something that costs a couple bucks to make really adds up and eats at any profit margin they would have had otherwise. This is a profit driven industry, so cutting a few pennies here and there can make all the difference when you are talking about mass production, and especially in the quantities that GM can produce.

From everything I've found, blocking off the rear ports *might* only be an issue for someone really pushing this engine beyond what it was designed to do. The people that have addressed it have been those with high HP setups (forced induction usually). GM knows that 95% (probably more) of people that buy something with this engine aren't going to be flogging the absolute **** out of it all the time, and those that do would probably have done modifications that would have voided the warranty anyways. Why worry about the minority of the population?

Those are just my thoughts.

Irish350

iTrader: (14)

^that

gm also put a 10 bolt in fbodies; if they didnt take the time to beef up my car i will

71ANTICARB

iTrader: (23)

I agree that GM is most definitely profit driven as their ultimate goal. I also agree that most people will not even come close to seeing the limitations of these engine. But I still do not see the benefit of the AN line other than its pretty.

patooyee

iTrader: (1)

Yes, I haven't ruled it out either. I don't personally own a TIG welder though. I have to call in favors from a buddy for that and this probably isn't worth calling one in.

J. J.

patooyee

iTrader: (1)

Great find, thank you!

J. J.

Andy1

If the motor is angled slightly back, then I suspect the front only venting would be adequate. In my swap, my motor sits level so I opted to run all four vents. I don't see a need to run -4 lines either, as you don't want flow, just venting. I'll probably get some comments on this, but I ran those Wegner Automotive fittings and used 1/8" compression fittings and high temp nylon tubing to my header tank. The tubing is small, and easy to route. If you're nervous about the nylon, you could run some 1/8 copper of aluminum tubing.

Andy1

Ravenous T\A

iTrader: (12)

http://www.jagsthatrun.com/Pages/Par...g_LSI-tee.html

makes for a clean look

patooyee

iTrader: (1)

I agree, -4 is just easier to find fittings for.

J. J.

Irish350

iTrader: (14)

cutlass_455

iTrader: (2)

I cant remember what that factory covers/caps/plugs whatever you want to call them look like on the truck engines right now, but would it be possible to drill and tap them to accept an NPT fitting?? That would be pretty cheap....I think.

serpentnoir

iTrader: (2)

That's what tomz28 did. see above.

cutlass_455

iTrader: (2)

I think tomz28 actually threaded the cylinder head itself. I was thinking of drilling out the cap thats normally equipped to the truck engines at the rear and tapping those for an NPT fitting. This way you dont need to risk screwing up your heads.