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Shaved Intake Manifold


Neveragain55

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I realize that I’m about to ask some questions that have been discussed (ad-nauseam) but the specific questions I have havn’t been covered, and if they have I haven’t seen any discussion on them in these forums unless I overlooked them, If I did let me preface my inquiry with an apology.

 

What I specifically want to know is if it’s ok to completely blend all of the offending raised sections & weld shut all offending orifices from the L28 turbo intake manifold and still be able to run heat & regulate the air properly.

 

I don’t care about the emission stuff.

 

If one completely gets rid of all offending holes and raised air regulator connections, how will the manifold regulate the incoming air?

 

I’ve seen these “completely stripped†intakes on turbo models so obviously it can be done.

 

I’m just concerned about the “air regulator†and keeping heat in the car.

 

I’ve attached some pictures of my intake manifold after it was blasted, and I also attached a picture of a turbo intake set up without these objects being lopped off.

 

I also just added pictures of my intake manifold with the areas I want to get rid of circled in red.

 

 

 

Thoughts and guidance would be most appreciated.

 

 

IntakeProject-2.jpg

Intake Idea.bmp

Intake Idea 2.bmp

post-24452-020669600 1327880993_thumb.jpg

Edited by Neveragain55
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The "air regulator" is for regulating the idle air mix...not anything to do with the cabin heater. It's just an idle control device (a big ugly one...haha) I'm doing the same to mine (stripping off EGR and idle conrtrol devices). Will end up making block off plates like in your pics.

I'm attempting to sand all the rough sand casting though to polish it too...got most all the rough stuff down to smooth now (SUCKED!!!) and I'm now working on hand sanding hard to reach areas to end up with hopefully a decent polish job. I'm really wishing I had just blasted it and left the casting (those pics from after blasting look sweet) :)

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You may need to speed the idle up a couple (or few) hundred RPM to help the car to stay on when it's first cranked up...that's what all that stuff is there to help out with. But guys with the shaved manifolds say that a good running L28 with the idle bumped up a bit will run just fine without all those devices.

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The only thing I noticed when I deleted my air regulator is that when the engine is cold it wont idle up, it will idle at like 500rpm. IF I try to drive it for the first 20ish seconds it will try to die every time I let off the gas. Not a problem so much anymore since I start it then run in to grab my backpack and stuff.

 

Here is a pick of my shaved manifold. Yours would be the same just with an EGR that you want to block off I'm guessing.

WP_000045.jpg

 

compared to stock:

PICT0820.jpg

Edited by BluDestiny
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I started with that same exact manifold, heres what mine looks like now. I wanted a non EGR, non webbed intake, but i dont like spending money.

 

I used a cutoff wheen to cut out all the large chunks, and a grinder with a 60 grit flap wheel to smooth it out. The top is a bit wavy, but it looks aight.

 

Welding was done with a spool gun on my mig welder.

 

photo16.jpg

 

 

the wrinkle coat didnt come out as good as i would have liked, but it will suffice.

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Really great work guys, I'm super excited now about shaving, cutting, welding, and smoothing her down.

 

I prefer the non webbed intakes myself but a lot of cats tell me that the webbed intakes help to avoid the whole "heat soak" issue.

 

Thanks for all the great advice and pics guys.....

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i have heard it both ways, my train of thought is that is more metal that can absorb it and pull it into the entire intake, especially because of the fact that the webs are almost in contact with the exhaust manifold. Yes its less metal to dissapate heat, but its less metal to absorb it as well

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The answer to idle is to use an idle bypass like on the N/A's. The Euroturbos have blanking plates over those AAR Ports, and they use a N/A Idle Speed Screw from the J-Tube to the manifold plenum same as on an N/A. I did that with mine, and it works just like any other idle speed device.

 

The throttle plate is supposed to be closed completely at idle on these engines. If you idled at all, it means something is holding your T/B Plate open, you have a leak or the T/B was not adjusted properly.

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I appreciate all the input guys, and all of it helps tremendously……………..

 

I’ve attached a picture of what I’m looking to mimic.

 

I basically want to take my intake, hack, cut, grind, and smooth out the surface to resemble the intake that you see here:

Shavedintake1.jpg

 

Once I get it to resemble the image above, the plan is to use one of those Palnet fuel rails or something very similar to give the engine a very 'clean" look.

 

This one obviously doesn't have the webbing like mine, but you get the idea.

 

It's nice to know that we can eliminate all of those things off the intakes and still use them.

Edited by Neveragain55
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I gave up in trying to polish my intake and am going to partially shave and paint instead. Any of you guys have recommendations on paint? I did VHT wrinkle (350 degree) on my valve cover and it turned out great...will this level of heat resistance suffice sitting right above a turbo with the stock heat shield still in place??

Also I don't wanna be too cheesy plugging the small holes on the side of the intake (from where the metal vacuum lines were mounted) but I can't weld aluminum...sooooo could the JB weld putty be used?? What do you all think?? I would think it should hold up fine, but maybe my hopes are too high.

 

Edit: Wow I thought about how silly the heat question was...fresh air is going to be rushing through that intake and keep it below 350 degrees (well it better be less than 350 :) ) I think I'll use the JB weld putty too in that case...unless someone talks me out of it :)

Edited by billseph
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I'm with you on the welding jazz Billseph...........

 

The last time I welded anything was about 25 year ago at Apex Tech in NY when I was learning how to do body work. I was pretty good but: (A.) I haven't welded in a very long time, (B.) I've never welded Aluminum and from what I've heard over the years it's presumably very hard to weld, (C.) I don't have any welding equipment.

 

I was going to buy one of those portable welding set-ups that Home Depot sells and experiment because I really need to get back into the art of welding if I plan on doing most of the restoration of my Z myself.

 

I never even thought about using the J.B. Weld, and I have used it on other things and it holds together great.

 

If you get the green light from the guru's in here to use it then I think I'm going to try it as well.............

 

We'll see....

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If that is what you want to mimic, buy one from the classifieds for cheaper than the materials and labor expended! You know the only advantage of the turbo manifold is the PCV is in the right place, right?

 

As for welding...go to the swap meet and find the guy using Lumiweld to repair beer cans with a propane torch. Stuff is great, and finishes just Luke aluminium. I "made" Euro Balance Tubes using it to plug holes, etc. It's METAL and works great without having to learn to weld. If your painting or chroming the part you will never know it's not base metal. The only difference I noticed was when polished/buffed the Color was slightly more blue than the base Nissan castings. Other than that, it's like it was welded in when in reality it was all done with a Propane or MAPP Gas torch and "brazed

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  • 4 weeks later...

Well I didn't end up going the JB Weld route...just had my machinist bud hook me up with welding the holes shut. My manifold was pretty trashed so he said all the funk that had soaked into the porous cast aluminum was making welding a bit more difficult, but we got it done up nice and ground down all flush :).

I hope these pics are okay, they looked decent in the preview...

 

You know what the manifold looks like already...here's what happened when I abandoned ship after trying to polish it "as is" These were some of the holes I needed filled.

post-13971-085402000 1330328783_thumb.jpg

 

All kinds of sanding, smoothing, drilling, tapping some holes, and all kinds of I'm sure unecessary work went into this thing before coating it with some VHT Wrinkle Plus.

post-13971-066194500 1330328358_thumb.jpg

 

A couple more shots for you with most everything mounted up and looking all purdy.

post-13971-056695700 1330328378_thumb.jpg

 

Those blockoff plates for EGR, AAC, and other stuff I chose not to use (losing compatibilty of some stuff with JWT 450HP upgrade) are just some pretty frikkin' polished aluminum and turned out very nice. Allen head fasteners all around were totally unecessary, but I think they look SWEET!

post-13971-070942000 1330328296_thumb.jpg

 

All in all, it's not show quality and it's not completly shaved, but it looks pretty nice and was fairly easy. I just REALLY hope the wrinkle coat holds up (I'm kinda scared cuz of how close it is to the exhaust manifold...)

Hope to see a few pics when you're finished with yours Neveragain55.

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