LS6 Intake Manifold Project Update
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LS6 Intake Manifold Project Update
Ok, here's an update on my LS6 intake manifold project. Been doing some work on it indoors this winter, waiting for spring to actually get in in the SS. I have included some pictures. I bought the following items used:
LS4 fuel rail with injectors
LS6 Intake manifold
Truck TB
LS4 DOD valley cover (not shown) I cut the Oil sender tower at an angle and had it welded to clear the LS6 intake neck)
Misc. parts, plumbing, wiring , hardware etc. gaskets (get real GM injector O rings only, the FelPro bottoms are too small!!)
I decided rather then try to bend the fuel rail to fit over the LS6 Intake (wasn't going well) I cut the interferring crossover piece out and replaced it with some brass fittings, and push lock nipples and hose ( good to 250 psi). I attached the brass to the stainless steel rails by soldering on the new pieces using stainless steel flux and good solder. Had to custom drill (1/2") the brass fittings that attach to the rail, easy. See the pictures.
I used a truck TB 78mm, it had a square opening in front of throttle plate that lead to the intake neck that we don't use, so I epoxied that up.
I drilled and tapped and attached some brass fittings on the TB for the PVC and brake booster vacuum line .
I soldered some fender washers to the fuel rail where it bolts to the manifold since the LS4 fuel rail mounting holes don't line up.
In the back, I removed the factory vacuum ports/MAP attachment adaptor by knocking it out from the inside with a long rod. I epoxied a large fender washer in the resulting hole. I will attach the factory MAP back here to the right and lower down to clear the Power steering pump.
I made an adapter wire harness for truck TB to plug into the LS4 wiring ( pins are just in different locations )
Now I plan to take it apart and paint the whole thing before it goes in. Probably red.
LS4 fuel rail with injectors
LS6 Intake manifold
Truck TB
LS4 DOD valley cover (not shown) I cut the Oil sender tower at an angle and had it welded to clear the LS6 intake neck)
Misc. parts, plumbing, wiring , hardware etc. gaskets (get real GM injector O rings only, the FelPro bottoms are too small!!)
I decided rather then try to bend the fuel rail to fit over the LS6 Intake (wasn't going well) I cut the interferring crossover piece out and replaced it with some brass fittings, and push lock nipples and hose ( good to 250 psi). I attached the brass to the stainless steel rails by soldering on the new pieces using stainless steel flux and good solder. Had to custom drill (1/2") the brass fittings that attach to the rail, easy. See the pictures.
I used a truck TB 78mm, it had a square opening in front of throttle plate that lead to the intake neck that we don't use, so I epoxied that up.
I drilled and tapped and attached some brass fittings on the TB for the PVC and brake booster vacuum line .
I soldered some fender washers to the fuel rail where it bolts to the manifold since the LS4 fuel rail mounting holes don't line up.
In the back, I removed the factory vacuum ports/MAP attachment adaptor by knocking it out from the inside with a long rod. I epoxied a large fender washer in the resulting hole. I will attach the factory MAP back here to the right and lower down to clear the Power steering pump.
I made an adapter wire harness for truck TB to plug into the LS4 wiring ( pins are just in different locations )
Now I plan to take it apart and paint the whole thing before it goes in. Probably red.
Last edited by Tappeter; 03-09-2010 at 01:04 AM. Reason: adding
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No offense man but I wouldn't put that manifold in my car with those brass fittings, they just create more places for failure if bending it was even a wise choice in the first place.
This looks well thought out and executed but I would fear leaks because that is fuel...and fuel on top of a hot engine is not good.
This looks well thought out and executed but I would fear leaks because that is fuel...and fuel on top of a hot engine is not good.
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No offense man but I wouldn't put that manifold in my car with those brass fittings, they just create more places for failure if bending it was even a wise choice in the first place.
This looks well thought out and executed but I would fear leaks because that is fuel...and fuel on top of a hot engine is not good.
This looks well thought out and executed but I would fear leaks because that is fuel...and fuel on top of a hot engine is not good.
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I am guessing you are both young, maybe too young to remember when all fuel went into engines from above through metal fittings into a carburator. Trust me when I say, these fitting will not ever fail, they will hold 100 times better then all the plastic fuel lines you find now in new cars. They are all carefully and tighly assembled with sealant, every joint is either sealed or soldered and will easily hold many times the pressure of our systems. You do realise that the black fuel line that attaches to your fuel rail is sealed with a single tiny rubber O ring, thats it, you think thats more secure and safer then solid brass?? Think again. I have no doubts about my set up.
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nice, the brass fittings will work just fine, i have ran similar setups using nitrous in the past on my 2 srt -4s that i used to have. my question is how much of a difference is there between this manifold vs the stock ported stage 2 one.?
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I have to think there will be a fair difference between even a stock LS6 and a ported LS4 manifold simply because of the "D" restriction in the TB neck and small plenum of the LS4 which for the most part cannot be "Ported out". Obviously this will be more evident a difference the more other power adder mods are made, such as better exhaust, higher ratio rockers or bigger cam etc. I don't know if the LS6 manifold is considered more of a power adder or a restriction eliminator. Either way you look at it, it adds up to more power.
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I think it looks slick! Nice work. I wish I had the time to do something like this. I'm just buying a ported intake and calling it a day. Unless you want to make these for us.... lol...
-Mike
-Mike
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Thanks, I just worked on it a couple of hours a week during the winter. About a hundred trips to hardware and pneumatic fitting stores looking at pieces, getting ideas and buying parts.. The only other things I am going to do to it is probably trim down those fender washers I soldered on to the LS4 fuel rail mounting tabs to match up to mounting posts on LS6 intake to make them look a little better and paint the whole thing. Duplicolor has a 2 part spray to make it look anodized red or blue, I am going with red for the manifold and blue for the fittings and TB. I also need to mount a MAP sensor to the rear of the manifold, hope to find another one cheap, I am trying to keep my original LS4 manifold assembly together and complete and untouched, in case I have to put it back on.
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Good luck with it. I think it should have come from the factory like that to begin with. When it's done let us know how the gains feel. I am really curious. Keep up the good work.
-Mike
-Mike
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It is my understanding from those that have tried to use the stock oem LS6 fuel rail that it will not fit on our engines. It interferes with the alternator. I just wish there was a way to simply bend our LS4 rail to fit well. Stainless steel does not take to bending well. I even had to use a special stainless steel flux to solder it to the brass fittings and steel fender washers. My only real concern is the push lock black rubber hose I got from the pnematic fittings store. The counter guy said it was ok to use with gasoline, but he didn't look real smart. It is Goodyear hose. I am going to take a small piece and put it in a jar of gas with a little fuel injector cleaner in it to see if it holds up. ( I use fuel injector cleaner several times a year)
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Thanks