Just spent the last 1.5 hours looking through about 200 threads on "mods" for the 2.8. Most suggest to port the exhaust manifolds. I want to do this on my 86 but I can not find a thread that shows/tells me "how". I understand what porting is, dremel tools, etc. and am capable of performing the work. What I need to know is should I weld the flanges on the outside to help strengthen the flange/pipe joint? If so, I am thinking that I should weld the outside before I grind the inside? I am assuming that the inside (see pic) needs to be cleaned out too? Any help would be greatly appreciated. Thanks in advance for your responses.
Pat
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07:59 PM
PFF
System Bot
katatak Member
Posts: 7136 From: Omaha, NE USA Registered: Apr 2008
I welded mine after bolting them to the old engine. That stainless welds very nice. Just let them cool completely while still bolted to the head so they do not warp. I also had to grind a bit of weld metal away as I got a bit too heavy so the nuts for the studs didn't fit right. (Rodney's stud kit)
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11:33 PM
Oct 15th, 2008
Intel Member
Posts: 752 From: Helsingborg, Sweden Registered: May 2002
I arc welded mine bolted to a piece of metal (1/2" thick) then used a drill press to open them up. I used a dremel to clean it up a bit. A 30 minute job for both.
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12:50 PM
fieroguru Member
Posts: 12306 From: Champaign, IL Registered: Aug 2003
I welded mine after bolting them to the old engine. That stainless welds very nice. Just let them cool completely while still bolted to the head so they do not warp. I also had to grind a bit of weld metal away as I got a bit too heavy so the nuts for the studs didn't fit right. (Rodney's stud kit)
Stainless? Are they stainless steel? Mine are pretty rusty to be stainless.....
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06:00 PM
PaulJK Member
Posts: 6638 From: Los Angeles Registered: Oct 2001
YUP! On both sides of the gasket, . . . ie. head matches gasket, manifold matches gasket. Don't forget to look into the 'Y-pipe', you know, where the two head pipes merge before the new high flow cat.. ;^) Just take a look, it's pretty intuitive what needs to be done, lotta buggers in there. Essentially cut out the material where the two pipes got smashed flat against eachother when they jammed them together. The seal can be compromised so have your welder dude/gal handy _after_ grinding for this part.
Norm
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12:25 AM
Patrick Member
Posts: 37674 From: Vancouver, British Columbia, Canada Registered: Apr 99
Don't forget to look into the 'Y-pipe'...Essentially cut out the material where the two pipes got smashed flat against each other when they jammed them together.
The seal can be compromised so have your welder dude/gal handy _after_ grinding for this part.
Don't you need to cut the Y-pipe connection apart to get at the material you wish to remove?
[This message has been edited by Patrick (edited 10-16-2008).]
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01:51 AM
Primaris Member
Posts: 550 From: Oak Grove, KY USA Registered: Aug 2001
Don't you put the gasket on the manifold, mark it, then grind the manifold opening to match the holes in the gasket ?
304 Results!
Now is it not annoying when some forum member plays at search Nazi or pretends to be an Admin? I can't stand such passive aggressive behavior, so I had to say something.
I understand how frustrating it can be to see so much of the same stuff on a forum you care about. When I feel that way I just don't post. I mean why post if you are not really helping.
Don't you put the gasket on the manifold, mark it, then grind the manifold opening to match the holes in the gasket ?
quote
Originally posted by gt88norm:
YUP! On both sides of the gasket, . . . ie. head matches gasket, manifold matches gasket.
Norm
NO not on exhaust, only the intakes. You want the exhaust port on the head smaller than the manifolds as it helps stop the back wave from entering the head.
quote
Originally posted by kawana:
what are the gains from doing this?
8 hp on open exhaust, dyno proven. Now I don't think you get 8 over the stock rating but it frees up 8hp to the wheels.
Quote from my thread
quote
Originally posted by sardonyx247:
I found that stock manifold has this crappy restriction in 2 of the ports.
I don't think THINK this is correct, but i don't know for sure that's why i posted the question. i thought the idea of porting any manifold was to smooth the flow of air and increase "breathing"; maybe there will be more posts.
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10:07 PM
PFF
System Bot
PaulJK Member
Posts: 6638 From: Los Angeles Registered: Oct 2001
maybe you didn't notice but this is NOT my thread. I just raised this issue (as a question) because i thought that people who knew for sure could comment on this technique which might be useful to the original poster - looks like i was right because others have.
quote
Originally posted by Primaris:
Now is it not annoying when some forum member plays at search Nazi or pretends to be an Admin?
that's not what i'm doing - if you think so, it's your personal issue.
quote
Originally posted by Primaris:
I can't stand such passive aggressive behavior, so I had to say something.
I guess this just proves what i just said.
quote
Originally posted by Primaris:
I understand how frustrating it can be to see so much of the same stuff on a forum you care about. When I feel that way I just don't post. I mean why post if you are not really helping.
Why don't you take your own advice - your rant didn't add a thing.
Maybe you hadn't noticed, but i didn't tell this guy to SEARCH. Why (?) because i didn't know how many threads were in the archives regarding porting exhaust manifolds. BUT, I HAVE been around long enough to get a "feel" for stuff that HAS been posted MANY MANY times before ad nauseum.
The BEST way to get info is to USE SEARCH when a lot of info has already been posted. If you don't, you wait and then are at the mercy of whoever happens to see your question and reply. Some people may not realize that a LOT of people have asked the same question - I do, so i posted "to search' only after I have verified that a lot of stuff actually Does exist.
Also, if you noticed, (with Very few exceptions) i haven't posted the SEARCH figure for any topic that has less than 60 or more threads in the SUBJECT line.
What you DON'T know is that some people have already thanked me for pointing this stuff out. No one really tells new people about search - that's why i recommended to Cliff that he add a section for it. Whatever ---- if I NEVER see another thread on "what engine swap should i do" it will bee too soon - and i KNOW other guys that have been for a while feel the same way.
My comment on the search thing. I went to the search function first. I typed in "Exhaust Manifold Porting" and got over 300 threads. After reading through nearly 1/2 of them, I realized that every thread I read had either the word "Exhaust", "Manifold", "Porting" and / or any combination of the three words. The majority did not have anything to do with porting the exhaust manifold. I'm sorry but threads that involve the installation of a 4.9 do not answer my questions about a 2.8. I also apologize for not being a word smith to be able to zero in on what I am looking for.
I started this thread so that maybe someone that had already been through this might be able to either direct me to the thread I was looking for or simply answer the question as many people have and I appreciate thier feed back. Using the "search" function is not always the best way to get the info you need.
Thanks to all that have had positive, constructive input to my original question. It has helped me a lot.
Last question.
If the flanges are steel and the tubes are some alloy, can I simply weld the flange to the tube with standard carbon MIG wire? Do I need an alloy wire? Not a pro welder but I can hold my own with carbon steel and have a few years experience using TIG on stainless tubing but have never welded carbon to alloy.
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12:00 AM
katatak Member
Posts: 7136 From: Omaha, NE USA Registered: Apr 2008
The fiero V6 exhaust manifold pipes are stainless steel ,, stainless is steel and low grade stainless will rust tho it is unusual for a V6 pipe to be covered in rust ...you have probably seen stainless dinner ware with rust on it..an old knife left outside in the dirt in my case.. It is not easy to port out the V6 ex manifold,, the steel sticking up in the port should be ground down wth out smashing it down.. I purchased some ported manifolds andthe port job on each set was sub standard Dyno test have been done on the V6 before and after port job normally a 5 hp gain will result,,another 1 or 2 hp gain can be had by opening up the Y pipe and porting this then close it up.. The exhaust manifold strangles the engine ,,THIS IS THE SINGLE BEST MODIFICATION YOU CAN DO TO A FIERO ??V6.. there have been reports on this forum saying the ex manifild was ported and no real increase in performance was noted,,The port job HAD to be faulty..you only have to look at the weld gooped at the entrace then eyeball the steel sticking up like a wall,, it would slow down gas flow ,back it up,, disturb the flow.. It is my arrogant stuffshirt opinion that a proper port job,manifold rattle can ceramic spray paint job,, y pipe port and straight thru, cherry, bomb thrush packed muffler will yield 8 to 12 hp ,,better yet the engine will run cooler ..Gas milage will improve ,BUT it is the increase efficiency that is important,, any modification to the engine will not achieve max advantage untill you open up the exhaust this is more important than intake mods,, the farts have to get out .. some manifolds have 1/3 of the port blocked all you have to do is eyeball one manifold porting the V6 manifold is a win win win win modifiction..
[This message has been edited by uhlanstan (edited 10-17-2008).]
For the average Fiero owner the best tool to port with is a black and decker drill with grinding tools & grinding stones also some files .. nicer is an air grinder or electric ..I have covered this before . I purchased some ported manifolds from the mall ,,I have discovered that there are 2 different size Fiero exhaust manifolds one with larger ports (comments??) the weld on the inner port tubes at the flange should be removed first,,get it cleaned up open it up 90% to the size of the inner port,, then work on the walls sticking up in the 2 to 4 inches after the mouth flange,, do not smash this down grind it ..if you have no patience then just grind it down as best you can ..the exit path going around the corner is very difficult to grind down you need a a curve file to do this just do as well as you can ,, the detail stuffs only good for 1/2 to 1 hp and is difficult to do the entrance should be smooth no weld up at the entrance smooth to where "the walls" were ground down here only the most dedecated port fanactic will achieve nirvana .. Of course the flange needs to be welded to the pipe so you do not have leaks..Painting with the ceramic paint will give a small boost to efficiency This work is very time consumming unless you have a Hi speed grinder ,,some of the finish work can be done with a dremel or similar tool
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01:29 AM
katatak Member
Posts: 7136 From: Omaha, NE USA Registered: Apr 2008
Going to attack it today. I have a air die grinder so that is not an issue. Any one have any ideas about using the "Header Wrap" on the logs and the Y pipe? I have used this on my SBC's with good results - greatly reduces under hood temp, etc. Would like to hear other opinions.
Thanks again
Pat
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02:50 PM
Doug85GT Member
Posts: 9707 From: Sacramento CA USA Registered: May 2003
Going to attack it today. I have a air die grinder so that is not an issue. Any one have any ideas about using the "Header Wrap" on the logs and the Y pipe? I have used this on my SBC's with good results - greatly reduces under hood temp, etc. Would like to hear other opinions.
Thanks again
Pat
If you use exhaust wrap, then be sure to paint the manifold with some 1200* + exhaust paint. Exhaust wraps hold water in contact with the parts and will eat mild steel really quick. Since the exhaust manifolds are low grade stainless, it may take a little longer. $10 for the exhaust paint is well worth it IMO.
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04:50 PM
katatak Member
Posts: 7136 From: Omaha, NE USA Registered: Apr 2008
So I got started this afternoon. I think I need to go back to welding school. My welds look like a dog s*#!ing peanuts! Nothing a grinder won't fix! Anyway, out of 5 logs that I have, onlt 2 are worthy of the work. I have a 3rd that has a dent on the Y pipe connection. Anyone have any ideas how to straighten this out? I'd rather use this one if I could save the end.
VHT brand is the best ceramic coat paint for the average owner ..I am using Dupli collor because I got it on a close out($2 a can) Jet Hot has a home application kit for a real ceramic coat ($20) the jet hot kit must have a sand blasted or PERFECT sanding job(not easy) to work properly The rattle can VHT is your best bet,, Advance auto carries this now .. the ceramic paint must be heated for best performance.. Follow the directions on the can,, you should heat this in an oven .. this will destroy an oven for home cooking ,you could get sick,,..you can place the manifold inside an metal container then place in oven You can cure on the motor read directions then follow as close as you can,,run motor enough to reach first heat level then shut off,this will be a guestimate let it coll down completely then just use normally and hope for the best. In lower southern states you can place in a box in direct sunlite ,if interior of box is black this will help with the bake the paint is hardened by baking it will not cure properly if not baked this ceramic paint uses nano tech and thier are midget critters moving in the paint REALLY ! A ceramic paint is FAR superior to regular heat resistance paint,,you must remove the majority of the crap on the exhaust (easier than port work) using wire wheels and sand paper the better the pre work the better the hold of this special paint A ceramic coat will lower the engine compartment temperature to take full advantage of ceramic coat the inside of pipe must be coated this adds much difficulty to the job to do a proper welding job on the flange to pipe you should be capable of a smooth puddle weld around the whole flange Also the alignment of the flanges is crittical you should be able to place a straight edge along the surface and thier should not be more than .010 difference,, under .005 better this will prevent breakage of pipe later It is not easy to properly port a V6 but mucho worth the effort for those not interested in a lot of grinding just cutting down the walls will result in a better working engine If you are interested in performance you must grind or cut 95% of the weld this means you must weld flange 100% to prevent leaks In dyno test the ported stock manifold has equaled the Fiero store headers,,but the fiero store headers will be superior if hi performance parts are added.. the Fiero store headers will work better at hi RPM they are worth the money and they are ceramic coated wish I could afford a pair (of headers that is
You are spirraled in a circular motion on the connection .. I have had some success using a 2x4 !! I place the 2x4 at the appropiate place and delever a blow with a large striking devise (hammer) after this if the blow delivered political correctness you must be a tin smith.. you can make a template from a normal connection just use a plastic large sode bottlew for the template cut your template in a parfect replica of the circular pattern desired,, this will fit tightly when you pass it over the normal connector The hammer delivery is critical,, to hard will make it worse just build up to level of force you need this onlyworks in 20% of cases but your options are expensive as mufflfler shops no longer provide this sort of service they use to have wierd expansion tools ..ask around there use to be a mushroom type tool that expanded to size pipes and restore connection features may be easier to weld another connector on ""carefully"" read all post enjoy interesting negative reports & post and use what applies to you.. GOD GUNS GUTS & FIERO,S made america great !!
[This message has been edited by uhlanstan (edited 10-17-2008).]
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08:14 PM
katatak Member
Posts: 7136 From: Omaha, NE USA Registered: Apr 2008
One down, One to go. Got one welded and completely ported today. Went through a few stones before I figured out what worked best. I used a Carbide bit in my Dremel to cut most of the metal and weld away then the die grinder with a stone to smooth it out. Worked great. Here's some pics of the end result. Thanks to all for your suggestions and help.
Pat
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09:35 PM
PaulJK Member
Posts: 6638 From: Los Angeles Registered: Oct 2001
For your future use, change the 3rd box in SEARCH to SUBJECT/User Name and you will get the threads that have been started with your topic instead of every thread that has made mention of it. In this case, 304 threads had a mention of "porting exhaust manifolds" but only 38 were started with "porting exhaust manifolds" as the main theme.
Something else you might consider:
Since these parts are so small, you might find out how much it would cost to have them ceramic-coated instead of using the header wrap. Ceramic coating is worry-free.
[This message has been edited by PaulJK (edited 10-17-2008).]
