Whats the best way to remove the webbing on a inlet manifold

[Noddle]

Just wondering whats the best way to remove the webbing on this manifold,

I was looking at removing the RED part , see image, the blue and purple may be too much of a hassle to do, the main reason I want to do this, is to make it a little nicer on the eyes, and to help with getting to the exhaust studs.

 

Nigel.

[gjc5500]

If i do say so myself, a dremel works nicely. Just dont remove too much. too much = vacume leak = bad

[cygnusx1]

Oh wow, I wonder where that exhaust leak was?

 

It might be worth looking for an early manifold on ebay or somewhere on the web. Try zbarn.com.

[slownrusty]

The webbing acts like a heat shield to the injector rail and injectors sitting right above it, so why would you want to remove it? Its not hideaous either and you save what maybe 1/2lb?

 

Yasin

[savageskaterkid]

Hes not worrying about wieght savings, but just it being ugly. I think its ugly too, and a PITA when removing bolts. I just got my N42 intake in, and I'm glad I did, really cleans up the engine bay.

[Guest Mike]

Does this help??

 

http://classifieds.hybridz.org/showproduct.php?product=3384&cat=17

[Noddle]

Does this help??

 

http://classifieds.hybridz.org/showproduct.php?product=3384&cat=17

 

Nice isn't it ?, but for $600 US and shipping to Tasmania, I don’t think so,

 

Cygnusx1, large cracks in the exhaust manifold, if you couldn't tell

 

Slownrusty, I will be running extractors, this should reduce the heat under the manifold, since it will have more clearance, and not have a huge thermal mass sitting there, trying to get every thing hot,

 

 

I think I will "hack" it, my time is free, and I have some tools, air compressor, Air pneumatic Die Grinder, I will need to get some carbide bits,

not sure about the purple and blue bits in the picture, I will have to pull out some of the plugs to see what behind there.

 

I'll take some pictures as I go..

 

Nigel

[BRAAP]

As for removing the webs, an air powered cut off wheel and/or Sawzall, could get the bulk of it, then using a die grinder, blend the excess left behind.

 

Now for that $600 intake… (BTW, thanks for the plug Mike…)

 

(In my best Billy Mayes infomercial imitation……)

 

 

Yeah, but that $600 gets you more than just a non webbed intake, that intake also accepts O-ring injectors, comes with a matching billet fuel rail, comes with custom matched 60mm NISSAN throttle valve AND braided stainless throttle cable set up for the Z car, ready to bolt in. Shipping to Australia most likely would be outrageous to say the least.

 

If someone came to me to duplicate that exact set up to that level, I would charge well over a $1k.

 

 

 

[vashonz]

I found that a grinding wheel worked much better than a carbide bit for taking off a large amount of material. The carbide just got loaded up with aluminum shavings and I had to spend alot of time picking the aluminum out.

[RTz]

I found that a grinding wheel worked much better than a carbide bit for taking off a large amount of material. The carbide just got loaded up with aluminum shavings and I had to spend alot of time picking the aluminum out.

 

Just touch your spinning carbide bit to a piece of old cast iron... cleans it right out.

[BRAAP]

There are different carbide bits for carving “ferrous” and “non ferrous” metal. Bits for Non ferrous metals, such as aluminum have much wider flute spacing and the actual cutting edge is a slightly different angle, just like milling machine tool bits. If you use ferrous bits on aluminum, they will indeed clog up, and clog up in VERY short order. Non ferrous bits will also clog, but not as often or as fast. The faster the bit is turning while you are carving, the faster it will clog, and the softer the material, the more it will clog as well. On the other side of the coin, using non ferrous bits on ferrous metal such as cast iron will dull the bits in short order, hence the need for particular bits for the material you are working with. .

For the Datsun aluminum intakes, a non ferrous cutter works fine with minimal clogging.

 

And as Ron Mentioned, when the bit clogs, run it across a piece of cast iron and that will unclog it. I keep an old Chevy Oil pump housing near by just for that purpose. Also, there are waxes available that will help keep the bits from clogging.

 

Here is post I wrote some time back in another thread about valve unshrouding, talks about and shows the different cutter bits…

 

http://forums.hybridz.org/showthread.php?t=110269

 

 

 

I’m assuming you are talking about the N-42 chamber that wasn’t welded. The sanding wrap marks are just for removing the “as cast” finish during the process of polishing, going to finer and finer sanding wraps to a polished finish for that head. We had no intention of removing material other than to get a polished surface.

As for what tools we use, For Aluminum heads like the L-series, We use cutters for non ferrous metal in a die grinder, (no Dremel tools here. I ported my very first head for myself using a Dremel and will NEVER do that EVER AGAIN! Dremels are for modeling, not porting.) These non ferrous cutters are more aggressive than ferrous metal bits and don’t clog as easily when carving on metals such as Aluminum because of the angles ground into and on the flutes of the cutters themselves. For porting Iron heads, such as OE Chevy heads, we use the ferrous cutters. We only use the sanding wraps to remove the high spot of the divots left behind from the cutters.

The picture below represents only a small portion of all the porting tools we use to port heads. The cheapo fat die grinder on the right is for hogging and the long skinny Dotco grinder is for finish work. The cutters along the top left are for aluminum, (non ferrous), and the cutters in the middle are for porting Iron heads. The dead valve on the top are my sacrificial L-series valves. They are nothing more than a pair of sacrificial valves which will help protect the valve seats from runaway die grinding efforts, and trust me, it WILL happen no matter if you have only 30 minutes experience or 2000 hours behind a die grinder, it still happens once in great while and those sacrificial valves will protect the seats from having to replace them because of an uh-oh. Speaking of run away cutters, “when” that cutter does grab and takes off across the head, if you position yourself and the cutter in such as way that “when” the cutter does take off across the head, it will do as little damage as possible, i.e. divot tracks across the deck surface, big gouges in the spark plug threaded hole, removal of to much material causing the head gasket fire ring to over hang the chamber requiring rewelding, etc. The more damage you cause, the more machining and material removal needed to clean up those uh-ohs. Tricks like positioning the cutter in such way that “when” it does grab and take off across the head, it only goes across the open chamber and not the deck surface. This requires repositioning yourself and the head in several positions for each and every chamber. Porting is very time consuming, patience demanding, job that requires experience to get it right.

If you have never done this before and are dead set on trying it yourself, try using a scrap head for practice. I don’t mean just doing one chamber and then moving on to your good head, I mean complete the head to its entirety, as mistakes will be made, and a scrap head is the best place to make the biggee mistakes. Making these mistakes on scrap head will help point out where your weak points are in regards to keeping the cutter from getting away from you. Using a scrap head in this manner allows you to mess up as much as needed so that you can establish little tricks that help you and your technique in keeping those inevitable uh-ohs to a minimum.

Hope that helps.

 

[Noddle]

Here is post I wrote some time back in another thread about valve unshrouding, talks about and shows the different cutter bits…

 

Thanks for that, I did read this about 4 months ago, but couldn't find it, I did do a search using BRAAP as the creator, but since you didn't create the thread, thats why I didn't find it, but I did answer one of your posts from another area,

[Noddle]

I found holes into the runners, behind the bungs , so I won't be able to remove the "blue" area in the original picture, unless I get them welded up, but since money short, and I'm trying to do it on the "cheep", I will remove only the "red" area.

 

I will pay the local wreckers a visit, I may find something, but since EFI " L " engines didn't arrive in Australia till about 1982 (I may be wrong, but I believe the early MR30, didn't arrive till '82), I may not find any non pollution manifolds.

[Guest Mike]

Are those cracks in your manifold or seams?!?

[Noddle]

Are those cracks in your manifold or seams?!?

 

 

"casting flash" I believe its called, no cracks.

[Guest Mike]

Whew... (wipes perspiration from brow)... that's good

[BRAAP]

I found holes into the runners, behind the bungs , so I won't be able to remove the "blue" area in the original picture, unless I get them welded up, but since money short, and I'm trying to do it on the "cheep", I will remove only the "red" area.

 

I will pay the local wreckers a visit, I may find something, but since EFI " L " engines didn't arrive in Australia till about 1982 (I may be wrong, but I believe the early MR30, didn't arrive till '82), I may not find any non pollution manifolds.

 

 

 

You can machine or carve off that EGR plenum that runs the length of the air plenum and then just drill and tap those holes using a pipe tap and plug them that way.

[Noddle]

You can machine or carve off that EGR plenum that runs the length of the air plenum and then just drill and tap those holes using a pipe tap and plug them that way.

 

A very good Idea, or maybe little welsh plugs,

 

Thanks for the hint,

 

Nigel

[Noddle]

Just spent 40 minutes with a grinder

It is slow going..

[Noddle]

I spent 2 hours or so tonight, I found using a drill made the job easier