intake manifold fabrication

[240zwannabe]

hey guys, i wanted to know if there is any sort of metal you all prefer to use in order to fab up an intake manifold? also what filler would you prefer to use? i was taught to weld through a 6 week class where they more or less focused in on the technique and less of metal makeup. thanks

[ihatejoefitz]

here is a pretty cool source for custom intake parts.

 

http://www.rossmachineracing.com/intakeparts.html

[johnc]

5052 or 6061 aluminum with 4043 filler for the 6061 and 5356 filler for the 5052.

[240zwannabe]

5052 or 6061 aluminum with 4043 filler for the 6061 and 5356 filler for the 5052.

 

 

will these metals hold a good amount of boost? I told my friend about this intake manifold idea i have where you have a TB on both the front and back of the intake manifold so cylinders 5 and 6 wont run richer or hotter than the rest of the engine and now they want me to make this manifold come to life because they're all going nuts over it.

[johnc]

I always find it funny when Turbo guys worry about things like this. A properly welded aluminum container can hold 200+ psi. Heck, even an empty liter bottle of Pepsi can hold 120 psi. I regularly pressure test any of my welded containers and AN lines to 100 psi. The silicon hoses will blow off before a propery designed and welded intake manifold will fail. You can also weld bung and a blow off plug on the intake manifold so that any huge pressure spikes blow the plug out before losing a hose.

[Brad-ManQ45]

Why not put the TB mounted in the center with a diffuser for the center cylinders? That would probably work better...

[veritech-z]

or run isolated plenums for the front and back cylinders in an over and under style (wasn't somebody on here talking about doing that for awhile?). I like Brad's idea better though, like the 5.0 HO mustang or the RB25 skylines, or the 7m supras, or some other performance motors that I'm not familiar with.

[cheftrd]

Or you could just run a single plenum with a single throttle like all the other hundreds of 750-1000hp RB26's and 2J's that don't have any problems. The five fastest RB26's use a single and don't have cylinder to cylinder AFR issues. There are ten million other, more important things to worry about before you get anywhere near the level where you need to wory about getting every little scrap of power this way. Anyway, I build the sheetmetal parts of all my manifolds out of 0.125 5052 H34. No problems, although once, a long time ago, there was one with an extra large plenum that expanded some with 30psi. It made it look way better.

[thehelix112]

I have been thinking about this a bit lately, and haven't really come to much of a conclusion, what I will say though is that I believe pressure differentiations (caused by a vacuum down one runner as the inlet valve(s) open) are much more quickly eliminated in a forced induction setup as the turbo is constantly slamming more pressurised air into the same location.

 

I think.

 

Dave

[Sam280Z]

John C is right. You shouldn't worry about holding pressure. The real issue with plenum failures is fatigue. Every time the plenum goes from vac to boost it flexes. This can eventually lead to a failure. The key is to avoid stress risers and design the plenum to be stiff such that it doesn't flex much.

[slownrusty]

here is a pretty cool source for custom intake parts.

 

http://www.rossmachineracing.com/intakeparts.html

 

 

Wow..very cool site! Bookmarked for the future!

 

Yasin

[JustinOlson]

Yeah, I use Ross Machinings oval runners and velocity stacks and -10 AN fuel rail extrusion on my audi intake manifolds:

 

[Lunar240z]

Im reusing an old thread instead of starting a new one.

 

Ive made a little progress on my intake manifold now that i have a 50amp breaker for my tig. I was throwing the breaker at 185 amps, still, but I could get a bit of welding done before it shut off.

I just jumped right in and welded the base of the intake manifold onto the cast runners. its not that pretty but it didn't crack

 

 

 

 

So now i have to open up those holes. Any suggestions? I've been using files and a carbide bit in a dremel, but that keeps filling up with aluminum, and its gettting pretty annoying having to take the bit out and clean it. It'd take at least a few hours to do it if i kept going at the same rate.

[Shift]

http://cgi.ebay.com/3pc-INDUSTRIAL-TITANIUM-UNI-STEP-BIT-REAMER-SET_W0QQitemZ230132865962QQihZ013QQcategoryZ58216QQrdZ1QQcmdZViewItem

 

just need to find one big enough.

[Roostmonkey]

you need something to keep the aluminum from loading up on the carbide bit. I use a cutting wax/soap. It comes in a tube about the size of a caulking gun cartridge and you run the bit into it to fill up the grooves and when it looks like the alum is begining to stick again, do it again.Ive never tried it but hand soap might work ( bar soap ).

[e_racer1999]

i've always used WD40 when porting heads. do you think soap/wax would work better?

[Derek]

i've always used WD40 when porting heads. do you think soap/wax would work better?

I use bees wax for saw blades, spray cooking oil (Pam) for sanding disks and Tap magic for aluminum on burrs. The wax on burrs has a tendency to load up the tool.

 

Derek

[e_racer1999]

sweet! i'll try some tap magic...