sleepyvg30e

iTrader: (1)

I am attempting to port out the exhaust manifolds and i needed to know what kit would be cheapest to buy this will be the first time i do any real metal work on the car and i dont wanna get ripped off with a kit i dont really need

also is there any advice out there for curing some of the exhaust manifolds weakness' like the exhaust studs?

BenStoked

iTrader: (7)

300zx turbo studs and good motor mounts take care of the studs.

akurtzer57

iTrader: (4)

If going to port out exhaust manifolds would be easier to invest in some aftermarket along with a y pipe if looking for performance.

sleepyvg30e

iTrader: (1)

i heard about the trubo studs any specific model like the vg30dett or just anyone with a turbo and what do you mean by "good motor mounts"?

im getting a full wsp kit to go along with it but im not buying any aftermarket headers for a long time

CapedCadaver

iTrader: (8)

good = not broken.

sleepyvg30e

iTrader: (1)

well they should be fine...

ive been looking at this kit if you think do you its too much or not enough and how much exactly do you think i should port them out
http://www.prostreetonline.com/x/dre...y-tool-kit.asp

and im gonna be using this for high temp paint i heard it can lower engine bay temps by 20 degrees just by spraying the manifold...
http://www.hightempenginepaint.com/Content.asp?id=4

BenStoked

iTrader: (7)

well, If you are gonna take the time to put good studs in, I suggest making sure the motor mounts are good.

as for the port kit, I do not recommend a cordless dremel/rotary tool. the job(done right) can take hours, and the battery will die many times during the process.

as for paint, http://www.eastwoodco.com/jump.jsp?i...emType=PRODUCT may be good

CMax03

iTrader: (3)

Which style exhaust manifold are you working on VE or VG? I don't think there's any help no matter what you do to those Oem VG's exhaust manifolds!

sleepyvg30e

iTrader: (1)

cmon man im workin on the vg my name is sleepyVG

but why do you say theres no heping he vg manifold from what ive been hearing porting out the old manifolds is really the only way of improving the stock design and that headers are just a huge waste of money unless you can design true equal length headers (but nobody ever has)

BenStoked

iTrader: (7)

because he's one of those ricer guys who thinks "if it's stock it sucks"
ignore him (I try to), and good luck getting this to work.

sleepyvg30e

iTrader: (1)

....aiight thanks but i still dont know the proper tools..... its gonna be awhile for me to get the whole kit installed but ive got a set of manfolds just sitting in a box i wanna atleast try to port them out before i spray them down

Pearl93VE

iTrader: (14)

I thought it was common knowledge that VG manifolds were crap? I think Cmax was just saying there is money, time, and effort better spent elsewhere where you can get more gains since VG headers are a bad design to begin with...

sleepyvg30e

iTrader: (1)

VG manifolds aren't crap the the manifolds studs are crap and can easily be replaced with ones that are not crap

also there isnt a single good review (that ive seen) for VG headers that are still in production most people who buy them and install them claim that they lose power and end up taking them off...

and considering the time and money thing ive already got the parts all i need is the tool and theres a whole list of things i could do with a tool like this (if i can find the right one) from BBK's to head porting

hell this tool isnt even limited to just my car i could start carving out wood furniture if i felt like it...

Pearl93VE

iTrader: (14)

The stud's aren't really crap per say, they're just subject to extreme heat, vibration from having old and loose mounts, and weather conditions for 15+ years. The DESIGN of the VG headers leaves little to be desired IMO, all boring them out will do is allow more unguided exhaust to flow through a crappy designed manifold.

If you're thinking getting all of those "uncomfortably" placed and brittle studs out, unbolting the y-pipe, removing the manifolds, and refilling/replacing the mounts is going to be an easy task for next to none, if not any power gains is worth it to you, than by all means go for it. I'm just saying I would invest my time and money into something I'd notice a difference in.

The only exception that I could see is if you had an exhaust leak from already broken studs, and/or crap mounts (which they probably are) and they needed replacement as maintenance.

CMax03

iTrader: (3)

SleepyVG, If you've got your manifolds off in your hand then, all you can port is the entrance into the short *** primaries. It's actually like a two piece design. The flange and primaries are all one piece cast and the neck is a split tube that has been welded to the upper, flange/collector crudely (frankenstien style). So you can do your thing...I just don't see how it's gonna help if downstream is restrictive. That's like putting on a big Air filter but the intake tube is only a 1.5"dia. x 36" long tube. Unequal or equal lenght headers would benefit us and Pacesetter has the header manifold and the Y-pipe available. I'm just gonna redesign the ypipe the way they should have from the beginning! The headers are good as gold it's the ypipe where the design issue are. There red arrows signify where I'll cut, slip fit, a fixed welded pipe in place of that 3rd slip joint. The lower image signifies the area in which a flex joint and 2 bungs will go and the are where the 3rd slip joint is that will be eliminated! Otherwords, I'm gonna turn the ypipe into a 1 piece design with a flex section just as the Oem.

sleepyvg30e

iTrader: (1)

are you saying that boring them out would cause turbulence issues and might actually lose power?

but i dont really see how thats possible it might not result in an "real performance gains" but its the next best thing to custom design equal length headers and if ive got the time the only thing stopping me is the cost of the tool

im putting on a full wsp kit to go along with it

CMax03

iTrader: (3)

That full swap is a WSP ypipe, cat and catback?

sleepyvg30e

iTrader: (1)

...yup every lil thing

Matt93SE

iTrader: (44)

Don't waste your time with the stock log manifolds. I know people that have had them extrude honed and nothing came of it. 1-2hp for several hundred bucks worth of work.

Install a decent set of cams and you'll gain more power for less time and effort.

DanNY

iTrader: (14)

the stock manifold designs are "pretty good" for what they are. porting them won't make much of a difference.

300zmax

I have used this paint on my own custom y-pipe and it worked great. just read the destruction's before use. also used it on my 89 mustang and it works great.
And do not use a cordless dremel! you will be cursing in your sleep!

and i fully agree with matt and everyone else. the gains are just not worth it. you will benifit more from JW cams. i feel having the exhaust ports smoothed out will be a far better than having the manifold moded would be better. find a professional for doing the heads unless you feel brave enough. the exhaust ports in the VG engines are horribly restricted and just cleaning them out give great improvement to the power band. but your biggest improvement will be the Y-pipe. the OEM y is just crap. i have the OEM catback on my car and just with the y pipe change the power was far improved. i have gone as far as restricting the egr valve to increase highway performance and fuel mileage. im still working on the mods for that to see if there is a benifit before i go posting great things. but any way good luck.

refer to this page for mods. well detailed and thought out
http://www.redz31.net/pages/headwork.html

jakeru

sleepyvg -

I have done a good bit of porting and if you are going to attack cast iron with a dremel, be sure to get one of their rotary carbide burrs. It will be really slow going though.

You could make really quick work of those cast iron bumps if you had either an electric die grinder:
http://www.harborfreight.com/cpi/cta...emnumber=44141

...or air powered one with 1/4" shaft. (You'll need a compressor for that though, so the electric might be the way to go for you.)

Be aware that the electric may be "on/off" and not variable. Maybe that's OK though. But there are speed controllers available that go inline with the power cord that you may find useful to make the die grinder work at a lower speed. This might be just the ticket:
http://www.harborfreight.com/cpi/cta...emnumber=43060

The electric die grinder really will have a lot of power... probably even more power than an air die grinder likely would. (The airs are kind of nice and compact though.)

If you step up to a "real" die grinder, there are a variety of "professional" 1/4" accessories you may find useful for porting projects:

1. carbide burr - there are available in various sizes and make *very* quick work of cast iron. If you can find and swing it, get one with a large diameter head and "soft" shaped tip (like a dome end or tapered end.)

they also have a carbide burr set that would get you started http://www.harborfreight.com/cpi/cta...temnumber=3745
(just be aware the thing that is not ideal about these is the heads are only 1/4" diameter... it would be better to have one with a larger head diameter... 3/4" ideally, 1/2" at the least... ebay has some if you search "carbide burrs". Just one really useful burr will do the trick and last a long time!)

whatever you do, don't get your hopes up with any "high speed steel" rotary burrs being useful, at all. They will quickly turn into junk and will not stay sharp. They may be OK for shaping wood but they suck for metal.

You probably only need one or two of the good burrs, and you'll be set for many porting projects to come.

This 3/4" egg shaped cross-cut burr on ebay is a bit pricey (at $30), but would totally kick the *** of that cast iron and be easy to make very nice shapes wherever it would reach:
http://cgi.ebay.com/3-4-EGG-SHAPED-C...3286.m20.l1116

If you're willing to go to a ball shape (which would still be really great) you could save a few bucks on this one: (at ~$16 for a 3/4" cross-cut ball carbide burr):
http://cgi.ebay.com/NEW-1-PC-SD-7-DC...3286.m20.l1116

Yet another option is a useful cylinder shape and 1/2" diameter (which at $17 would be cheaper than the same shape in 3/4" but still be very useful) I have this exact configuration of burr and can get a lot of use out of it:
http://cgi.ebay.com/SC-5D-Cylindrica...3A1%7C294%3A50


Probably just start out with one (or maybe a couple) of the "good" burrs, and try it out, and you can always get more of whatever you find you still need. Pretty much any burr without "sharp" edges will give good results for porting. "sharp" edges can quickly make very damaging gouges which you probably don't want in your manifold walls, so best shapes are pretty much anything rounded.

2. 1/4" mandrel with sandpaper rolls - there are various lengths of 1/4" mandrels available, depending on how far you need to "reach" into the hole you are porting. And there are various grits and diameters available of sandpaper rolls. You can get the rolls in cylinder shape, cone shape, and hybrid (cylinder with cone tip.) I recommend the cylinder or the hybrid cylinder/cone shape. Get some really rough grit sandpaper rolls (like 60 grit) to quickly remove the cast iron if you don't have a carbine burr to do it. A large diameter roll will make it easier to get a smooth, desired shape. Follow up with a fine-grit roll (like 140'ish? +) to get a really nice smoothed out texture.

3. Flapper paper - buy a roll of ~1" wide sandpaper (emeory cloth recommended = has fabric backing), and buy a 1/4" steel dowel, hacksaw a slot in the end, put sandpaper strip into the slot, stick into your manifold, spin with die grinder to get a great finish. (Note you could get into this setup for cheap if you had the die grinder since the steel rod + emeory roll is readily available.) It's really nice for getting a really smooth finish all over. You can get a good finish with large diameter sandpaper rolls instead, however.

harbor freight has emory sandpaper rolls really cheap...
http://www.harborfreight.com/cpi/cta...emnumber=93069

Go here and read up to learn about the above and more (not necessarily to buy from them, they are not the cheapest):
http://www.mondello.com/index.htm

(actually, hmm... I seem to recall they used to have much more info on their website. Here we go, internet archive action! Use this link instead for more info:
http://web.archive.org/web/200308100...talog_menu.htm )

DanNY

iTrader: (14)

wear protective gear when you're doing this.

sleepyvg30e

iTrader: (1)

i know jwt camshafts ... u reccomend that mod alot... but i think its necessary to get the set with the springs and lifters and that costs

this is what i feel like doing now that ive inspected them a lil closer think it would be best to just smooth out the welds and the 02 bung and clean up that lil ridge cmax03 pointed out and just try to polish the inside as much as possible

thanks for the tips on the paint im guessing whites the best color for the manifolds when it comes to heat
...wow

thanxs alot for all that information that was the most useful thing i couldve have asked for

one question that i would haveleft would be the necessity of the speed controller is it really gonna be that powerful that i would have to lower it or can i save that purchase for when i start another job?

but basically theres alot of ways i could go about starting it so it seems that this setup is what u reccomend most to get the job done...

$14.99 speed control
$39.99 electric die grinder
$17 carbide 1/2" burr
$5.99 180 grit 1"x50
$2.99 50 grit 1-1/2"x80

$87 total

jakeru

Yep, you could do a lot of good things and get a decent exhaust manifold port with that setup. Don't forget the 1/4" steel rod for the sandpaper to make your "flapper roll" (any hardware store would have that cheaply in the bulk metals supply section)

And, you could also easily add to that setup in the future as the budget allows (to say, add some cartridge rolls, etc...) If you find there to be too big a "jump" from your carbide burr to your flapper roll, the cartridge roll could be handy but I think you could get by with the course ~50 grit emory roll, that's pretty rough stuff. It does work best if you "center" it in the port and just let centrifugal force press the sandpaper against the walls and you can move it along the port to get a really nice smooth finish all along the walls. Starting with a long strip several inches long, you can tear it off as it gets worn to expose fresh grit, and also flip it over to use the other half. You'll figure it out, it's pretty fun stuff really. If your burr can't reach something in there deep, you could probably eat it away with ~50 grit successfully too. Just go all over with the course sandpaper until all the carbide burr marks are gone, then finish with your 180 grit and you will have a really pretty, nice, smooth ports left that will likely look professional.

I think I'd include the $15 variable speed control from the beginning. Here's why: I think you are going to want it if you don't get it. A few years back when I was doing my porting type work by dremel, and I first tried one of those electric die grinders to use for porting, I ended up returning it because the "on/off" nature just didn't allow enough control, and for doing many things the full, ~22k RPM is just too fast and dangerous. (The carbide burr will probably take that speed but the flapper paper will likely self destruct. You also can't use things like mini wire brushes because they would self-destruct at 22k RPM.) I later learned the "pros" use those speed regulators (like the $15 jobbie) to control the electric die grinder's power when using them.

The variable speed will be nice for the flapper paper because the more speed, the more centrifugal force will force the sandpaper against the port walls and you can control how quickly it works by varying the speed. It may also just feel a lot safer to have the speed control.

300zmax

i think the black is the only thing you can get that will hold up to the temps. but i maybe wrong and didnt see it. i love eastwood.com its is the sh*t. great sales. know their stuff.

Matt93SE

iTrader: (44)

Speed is expensive. how fast do you want to go?

There's more power in headwork, cams, and cam timing than anything else on the engine short of a turbo.

porting the manifolds is still going to be expensive if you don't have the tools yet. it's going to be a ton of work, and unless your engine can breathe from cams and headwork, then the exhaust mods aren't going to help much, if any.

sleepyvg30e

iTrader: (1)

well thats true but i cant help the feeling that just slapping some cams on there is not the best way to go about it...

i wanted to go through the whole process of doing the headwork myself installing springs and lifters an underdrive pulley (which i just purchased) and adjustable gears i wanted evrything looking polished finished and clean like these:

but if your trying to tell me that just buying the cam shafts with the spring kit is more important than all that other stuff or that everything else can wait for a later date i might consider buying it a lil sooner...

its part of the reason why i wanna learn how to port on these manifolds so i can get a good idea before i buy a set of practice heads

Matt93SE

iTrader: (44)

if your'e going to do the other stuff eventually, then go for the manfiolds. knock yourself out. just don't be disappointed when they do nothing.

300zmax

matt is just pointing out that the manifolds with and with out head mods will make insignificant difference. best bet it to get the practice heads and go to town. there are some great ariticles in 5.0 and Fast Fords mags that give some of the best tips for DIY head mods. besides who is going to see the inside of your manifolds. i would hit up summit racing buy a header kit and make up a set of nice shorties (assuming you can weld or know a guy) usesing the manifolts as templates. i have a donor car that im going to pull the manifolds off just for that reason, but i will be looking to do it just for practice and looks more than practical reasons.

we just dont want you to do all that work with no pay back, and the manifolds will grind much differntly than the heads. the heads need a lot more time and care.

sleepyvg30e

iTrader: (1)

im not really concerned about performance payback im really doing it because this is the last thing i will have to do on the exhaust sorta like the cherry on top the same reasons why i dont wanna get the jwt cams is the same reason i wanna focus on one project do it extremely well even with a lil overkill then move on to the next...

this will give me decent practice as a "my first metal project" obviously if u get the impression that im close to welding out my own set of headers then u dont understand that i dont know crap about cutting welding or any other metal work really

if i get this setup im still saving money compared to pacestter or dorman oem's so im not really mad about the tools even with the paint the gaskets the turbo studs and the speed controller im still saving money..

porting the stock exhaust manifolds isnt exactly a great mod but it is a great practice mod if ur interested in doing more serious projects later on

jakeru

It sounds like you can easily justify the exhaust manifold porting as a "learning project". If there is a small performance gain (which I wouldn't rule out... those ***** inside the manifold look like they could cause a bit of turbulence and backpressure to me. It certainly wouldn't *hurt* performance to remove them, it could only help!) you could consider it "icing on the cake".

Also as others have correctly pointed out, if you do future mods that increase the airflow through the motor, the exhaust manifold porting&polishing could provide additional performance benefit.

IMO, it's better to learn on a project you can actually bolt on your car, test, and YOU (not someone on the internet who has probably not tried the exact same mod with all other factors being equal) can be the judge as to if it made any performance improvement. If it doesn't make any noticeable improvement, at least you've ruled it out.

You can easily let others see your work by taking pictures before installation. (If you do, please share them here and I'll be interested to see how well the harborfreight setup works!)

Also, the die grinder + accessories will be a great investment for future porting projects.

It is true that aluminum ports "differently" than cast iron. Specifically, it is a lot softer (so more effortless to remove material), and it also is a bit "stickier", which can load of the burrs (there are special burrs made specifically for aluminum that have a wider "teeth spacing", and no cross cuts, which helps keep the aluminum from loading up between the teeth.)

I would say it would be easier to try out your first porting on cast iron because it will go a little slower and be harder to do "mess up," and you won't have the hassle of aluminum loading up your burr with the specialized aluminum burrs.

The head I recommended with the cross cut is really optimized for cast iron. It will work on aluminum pretty well, but there are special aluminum cutters (with wider teeth spacing, and no 'cross-cut') that are really the cat's meow for removing aluminum. Anyhow, given that you don't presently posess a set of "junk" heads for practicing on, and seem willing to take your car out of commission to work on it's exhaust manifolds, I think it makes sense to practice on your cast manifolds and actually test them out afterwards.

I can tell you looking at those pictures that there is a possibility porting those irregularities out will make a small gain. When you have the manifolds off, also inspect closely how well that mate up to the heads. If there is any material "hanging in", you can sometimes see benefits by port matching.

An easy and professional way to port match, is to get a black sharpie pen, color the surface of the manifold that mates to the head, hold the gasket in position up to the manifold's inlet, and use something sharp to "scribe" (scratch into the surface) the inner dimensions of the gasket, then use your porting tools to remove material up to that scribe line.

How well the port matching will increase power depends on how mis-matched the ports were cast out of the factory. (I found the factory port match of the VG's intake manifold piece to be pretty bad in this area... Check out the areas I removed of the *downstream ports* of the VG intake pieces I posted up here: http://forums.maxima.org/6784677-post8.html )

Do a port match, remove those ***** sticking inside, and polish the whole insides with 180 grit to a shiney smooth surface and I'd be surprised if you don't help those exhaust gasses slip out of there more easily!

PS - for a coating to use on the outside of the manifold, I have used (on a turbocharger bearing housing before with VERY nice looking, non rusting and so far long lasting results) this brush-on, factory grey looking product by eastwood. I think I'd recommend it over a spray on product like the black, because you can brush it on pretty thick and seal up all the pores quite well. But I guess the spray on could work well too, it may depend on on whether you prefer black manifold, or a more "factory cast iron grey" look.

http://www.eastwoodco.com/jump.jsp?i...emType=PRODUCT

*edit* - actually it might have been this one ("stainless steel" color) I used, I can't remember but the results looked really good:
http://www.eastwoodco.com/jump.jsp?i...emType=PRODUCT

I probably have some pics saved of the coated pieces I can post up later if you would like.

I think the eastwood "stainless steel" high temp coating is a little more brighter, aluminum-y in color than their darker "factory grey" high temp coating. Anyhow, I would thoroughly recommend either of the brush on coatings for any cast exhaust parts.

Getting a 1/4" drive mini wire wheel, and chucking that up to your die grinder might be a good call to easily remove the bulk of the manifold surface rust prior to applying the coating.
Here is a *cheap* ($3) kit harbor freight sells that would do the trick with your *speed-controllable* die grinder:
http://www.harborfreight.com/cpi/cta...temnumber=1341
(note 22k RPM is way too much for the wire brush so you'll need the speed controller to be able to use them for sure!)

Gotta love harbor freight for "one stop shopping". LOL!

jakeru

PS - i know it's a matter of personal preference, but the factory cast iron manifold may have something going for it lacking in the aftermarket tubular header... durability. I've sure seen some old aftermarket tube headers rusted away to oblivion. They just don't tend to hold up as well (unless you spring for spendy stainless steel) They can also readily crack, etc. (I'm not speaking from any experience with *maxima* or nissan aftermarket headers, just aftermarket tubular headers in general.)

Cast iron factory manifolds, on the other had, tend to be virtually bulletproof and virtually always last over a period of many decades. So if you *can* get good performance out of cast iron manifold, you may have a durability benefit you wouldn't have if you went with thin, rust and crack prone aftermarket tube version. OK I'll get off my stump now. Have fun!

CMax03

iTrader: (3)

I just love how the rear most cylinder on each bank has to flow somewhat(reverve flow) against the other 2 cylinders of the same bank in order to go downstream to the y-pipe on the VG... I'll keep my eyes open for a boneyard VE exhaust manifolds, I curious on whether they'll fit the VG head and mate up perfectly to a VE y-pipe ?

300zmax

ATP and spectra have the same part numbers listed on the VG and VE manifolds so i would venture to guess that they are the exact same. but thats on the rear manifold. as to i can not find the front.

internetautomar

iTrader: (30)

as usual people fail to read the footnotes.
it states SOHC only.
The VE and VG use different manifolds.

300zmax

your right. oops. second time in a week i missed something like that. i picked a bad time to quit drinking. lol oh well i have tonight to make up for it happy new year.

Nismo87SE

The problem with the manifolds is that they aren't designed for anything other than stock. Once you add mods headers are the way to go. Porting the VG mani's might get 1-2hp if your lucky but a properly designed header will make a lot more power. Matt is right if you want power from a VG cams + bolt ons is the way to go, but you'll hit a limit after that anyway. Also if someone does install cams please add valve springs, I did the cams only and floated the valves at 6000rpm which destroyed my engine! Sure it costs more but you'll make more power up top and be a lot safer as you rev the engine.

vg30guy

what are some good cams i can buy at a decent price. let me know.

300zmax

http://www.jimwolftechnology.com/cus....asp?PartID=27

http://www.jimwolftechnology.com/cus...l.asp?PartID=4

i think they are cheap as far as cams go