ToxicWS6

im looking at building my own sheet metal type intake manifold at this point, i have access to an aluminum welder (if i use aluminum) and all, im looking at pointers on how to design to get the specs i want, long intake runners, short ones, how far into the intake they go etc etc. if this comes out badass, awesome, if its comes out a bit better then an ls1 intake and costs less then $500 then thats the minimal it needs to meet lol (which i dont think it can be that bad or that expensive but)

heres what the engines goals are

-6400rpm red line (so idle/1800/2k rpms to 6400 power band)
-6.0L lq4 on 12 psi (possibly more boost in future)
-6 speed car
-weekend street mainly road course car, some 1/4 mile
-not cutting hood or cowl


with that being said here are thoughts on what will be different that i assume will make a difference in performance

-intake runner length
-intake runner length once entered into the main chamber (how far do they stick inside the manifold)
-main chamber/manifold volume/size
-angle the intake runners at all towards the front of the intake/tb area or have the straight off of heads

any input or suggestions are helpful, the idea of building this myself is also incentive to go this direction then just buying an intake also as i also have time on my side so it wont be a rush ether

SKULL

iTrader: (7)

my only suggestion is buy a high ram or pro flow to cut and fit. I believe youll have a lot more then $500 trying to make flanges runners and such.

if you did it. make it from aluminum. it be 1/4 the weight look a lot better and can be polished.

ToxicWS6

yeah, the "premade flanges" i was thinking i could get for $100 or less dont exists, so cutting one up like u said seems to be the cheapest option, u get injector bungs and etc also so not terrible, that alone throws the $500 out the window lol

cptinjak

Need to know goals and details on the rest of the setup to say much about design.

What kind of machinery do you have access to? A manual mill at minimum is pretty much necessary in my opinion. Also make sure you have a block you can bolt the heads that you will be using (not another set) to with proper size gaskets to ensure proper fitment. A good die grinder with a variety of long burrs and cartridge rolls are also crucial. Plan on a lot of hand finishing.

Jack

ToxicWS6

2000 trans am, t56, 9in with 3.70 gears, 60lb injectors, t76 turbo single, air to air intercooler, 80mm bbk TB.

i have a blown 5.3l i tore down to a bare block that i use as a mock up block with bare heads on it, possible acces to a mill at work if they let me, besides thag hand tools and did grinders, angle grinder drill press etc.

my thoughts atm are using a carb intake, cutting flanges off, getting some aluminum sheet metal and basically be cut and welding, understand cleaning the runners and TB area woth bits but (im asking not arguing) what do u see me needing the mill for?

thinking weld top plate last so i can get into everything

rryan5429

iTrader: (3)

Check out Rotary1307cc on his build thread in the conversion section. Zac is in the process of doing a modified intake based off one of the knock off Ebay sheet metal intakes. He's put quite a lot of work into it but I think it's going to be a pretty bad *** piece when it's done.
At the very least will give you some more ideas.

Rick

ToxicWS6

ok cool, ill check out what hes go going on too then, right now im at the, gather as much info as i can, point to see how do able it is for me, money, time etc wise, and if its something ill have as a side project and install it when its done where as i dont have an intake atm and need one.

was messing around on autocad last night coming up with some ideas, found some great forums, via my phone though, if i can find again ill try to post them here for the info on them.

cptinjak

Maybe I'm just spoiled, but attempting a project like that without a mill sounds terrible. being able to bolt it down, square it up, and make straight cuts.

I'm a big fan of straight runners, as long as is reasonable, with as much plenum as you can fit under the stock hood. Take care to aim the throttle body incoming air away from the runner openings as much as possible. Zbrown has a build thread going of a really cool custom intake with a bottom feed plenum.

In all reality, a boosted application will mask a lot of shortcomings in heads and manifolds.

Here are some photos of the manifold I did for my N/A street car. The design may not be what you are looking for, but it shows how I did most of the work on the mill, like cutting the runner openings and facing, drilling, and tapping the lid flange. Don't mind my terrible welding skills. I had never welded aluminum before... https://www.facebook.com/media/set/?...6255259&type=1

Jack

ToxicWS6

all the piping we run at work we have to have square and beveled and all, we just use slide squares, sharpies and angle grinders, so it maybe off a 1/64 if so its not noticeable at all once welded, for the end of the runners there gunna get die grinded and polished no matter what i use in the build process also so im not super worried about it, its still in the air on the planing part

cptinjak

Another reason a mill is nice is that once you've finished doing that much welding, the chances of the flanges sitting flat on the head is slim to none. Having a big roll fixture that you can use to cut both flanges 90 degrees apart in one exact setup is nice.

Either way, keep us posted. I love seeing people's projects like this.

Jack

Buchhakj

There is a lot involved if you are looking for good results. There have been a lot of people who have tried. There are some companies who sell premade runners (I thought this would be fun also) until I got quoted $2000 for machined set. There is a guy who built one out of carbon fiber that was amazing (ls7)

Lasershop

iTrader: (2)

Got to have a mill and be proficient with it. A drill press at the very least. Building an intake manifold is a very advanced project for anyone. There is no Ebay intake flanges. CNC machining costs a lot. I admire your enthusiasm but like anything else you must count the costs and take inventory of your abilities.

Most guys who attempt something on that scale have been machining and welding for years. I built one that is, except for the plenum, literally glued together. Well, epoxy actually. Welding aluminum is hard for me mostly because I don't quite have enough TIG power from my Miller Econotig. Here is the LS1Tech
thread:
https://ls1tech.com/forums/forced-in...-few-pics.html

ace_xp2

Couldn't you weld it while mated to a junk head? That would keep the distortion down wouldn't it?

Buchhakj

If you were to tig weld it distortion would be minor anyways. Aluminum is a huge heat sink. We preheat thicker aluminum with a propane torch before welding it just to get a good deep penetration with a Lincoln 175. Once you got it all tacked together I'd pull it off and slowly jump back and forth. Shouldn't have any issues.

cptinjak

You should weld it while bolted to the head, yes, but it will still flex and distort when you unbolt it.

Jack

SKULL

iTrader: (7)

that thread/motor was insane

Buchhakj

Agreed! Unreal is the word that comes to my mind.