Custom Intake Manifold

[ericjon262]

also, FWIW, a lincoln Pro-mig 180 set to heat range "D" and a wire speed of 7 seems to work well on the stock castings...



The neck had been cut off of the intake, and it's back on there secure now...

[ericjon262]

you can make 500 whp with the ported 3500 manifold and a 65mm tb. Once again, how much power do you plan on going for? No reason to modify something that can make more power than your goal.

MORE POWER!



Lol, I'm mainly wanting to do this to see how far I can take it. I have a ported upper and lower already, and I figure why not do something with the other 3 manifolds I have collecting dust. If it works and is legit, cool. if it doesn't, well than I will throw the ported parts and 65mm adapter back on and roll.

you can make 500 whp with the ported 3500 manifold and a 65mm tb. Once again, how much power do you plan on going for? No reason to modify something that can make more power than your goal.

[ericjon262]

that's actually a much better term.... after re-reading, it seems you want a plenum for each bank, so i guess that was kind of useless info.

Maybe, but for now, I'm just going to modify a stock 3500 manifold.

[robertisaar]

From what I have seen, it's a dual volume single plenum, but I've never had one in hand to look at.

that's actually a much better term.... after re-reading, it seems you want a plenum for each bank, so i guess that was kind of useless info.

[ericjon262]

Bolting down a custom upper intake is easy, just build it on a 1/4 inch thick aluminum plate, cut holes to match the LIM and then put anything you want on top of it. Mine was dead easy to do and bolted down perfect. If you want round just split a tube and weld it on. Sorry mine is painted black so it is not easy to see, but I think you will get the idea.

Larry

[ATTACH=CONFIG]7224[/ATTACH]
[ATTACH=CONFIG]7223[/ATTACH]

yeah, it would require some kind of a bridge to go across the top so it would bolt down evenly.

[ericjon262]

isn't the LZ9 intake considered dual-plenum?

From what I have seen, it's a dual volume single plenum, but I've never had one in hand to look at.

[ericjon262]

why do you want to modify the 3500 lower? You plan on making 700 hp? Whats your goal for hp? You seem to be spending so much time modifying everything, where the stock parts or ported, will support your power goals

I'm not going to, I was thinking about it, but I have now realized that the design is a already better then what I had thought, so I'm not going to touch the lower(I already have a ported one...) the upper on the other hand hand has plenty of room to improve.

[trotterlg]

Bolting down a custom upper intake is easy, just build it on a 1/4 inch thick aluminum plate, cut holes to match the LIM and then put anything you want on top of it. Mine was dead easy to do and bolted down perfect. If you want round just split a tube and weld it on. Sorry mine is painted black so it is not easy to see, but I think you will get the idea.

Larry

why do you want to modify the 3500 lower? You plan on making 700 hp? Whats your goal for hp? You seem to be spending so much time modifying everything, where the stock parts or ported, will support your power goals

[robertisaar]

Dual plenum is a definite possibility. Bolting it to the LIM could get tricky though

isn't the LZ9 intake considered dual-plenum?

[JerryRigg]

If it was cast as one piece with a brace in the middle or fabricated with a support in the middle it should work fine

[ericjon262]

Dual plenum is a definite possibility. Bolting it to the LIM could get tricky though

yeah, I thought about that after I posted it and looked at the bolt pattern...

[JerryRigg]

Dual plenum is a definite possibility. Bolting it to the LIM could get tricky though

[ericjon262]

well, I'm bringing this thread back again...

My original thoughts were to have the new, custom intake, follow the blue line, instead of the red line (stock)



I have now realized though, that this would probably not benefit like I hoped, because it would be a sharp snap bend from the intake ports to the ITB that I was planning.

upon looking more in depth at the LIM and Head, the stock LIM is actually a very good design, much better than I originally thought. the intake port bends to the LIM, in a very smooth efficient curve, and then the LIM takes a straight shot to the curve for the UIM. I'm beginning to feel the best place for improvement on the LIM, will be at the bend to the UIM.



by enlarging or making the vertical transition slower, I feel a gain could be made. the problem you then run into is the fuel rails, which could be taken car of with a fuel manifold and individual lines.

I now feel like the best way to improve the 3500 intake system would be with the UIM, which in my current opinion, could use vast improvements.

1.there is quite a bit of volume inside, that probably sits idle not moving a whole lot.
2.the throttle neck extends way back into the plenum, probably helps some for low speed, but I feel strategically reducing plenum volume would yield better distribution and flow.
3.The outlet ports on the UIM are holes, not a whole lot of bell mouth to them to allow air to smoothly flow into them, yes they can be improved through porting, but not very much.

what I now envision as the best option, would be a dual plenum setup with two smaller plenums and two throttle bodies, or an ITB setup. I am currently working on modifying a UIM to improve on some of the noted problems that I have seen. I will post pictures as real progress is made.

I'd like to hear the rest of your thoughts on this, so please speak up.

-262