Hi, I'm planning to replace my cabin side exhaust manifold gasket because it is leaking in two spots, and I think that is why my gas mileage is so low (around 15 or 16mpg). I just have a few questions regarding it: 1.) I am only planning on replacing the gaskets because my manifolds aren't cracked or warped, but do you think I should take the time and take them off and port them? I have no experience porting them, and I'm not really needing more power because I'm not racing it. What do you think? 2.) If I do end up porting them, I would probably paint them as well, do you have any tips on certain paints to get? Do you think the Dupli-Color high heat 1200F spray-paint, item number DH1602(black), would be good? 3.)I plan on using PB-blaster on the bolts the day and night before, but if I do end up breaking one, so I have to take it to a shop to get taken out or is there any other low cost option? 4.) Regarding specific gaskets, should I just use the standard Fiero gasket, or go for the 1963 Volkswagen Type 2 exhaust manifold gaskets (Cheaper, and pictured below) 5.) Should I apply any silicone sealer or any spray to the gasket and or manifolds? I read something about someone using copper spray? 6.) I think the best route would be to get brand new studs in case I need to remove them at a later date, but what do you guys think? And where should I get these?
Sorry for the million questions, but I'm just trying to plan this all out ahead of time in case I run into any obstacles, and so I can keep this a one day job. VW Type 2 gasket: Anyone use these?
Edit: Forgot to say it is an '86 2.8
[This message has been edited by Nitsua (edited 12-26-2010).]
IP: Logged
09:31 PM
PFF
System Bot
phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
4) Either 5) NO - Silicone sealer will burn up and also isn't good for your O2 sensor. I like the feel of 'bare'. Make sure the sealing surface of the head is flat and not notched. 6) I believe Saturn studs work fine to replace the bolts. I would for sure replace the bolts with studs.
Edit
As stated below - Be ready to pull the head if you break more than one bolt. Expect to break more than one bolt. Once you break more than one bolt leave the exhaust manifold on the head till you take it off.
If you haven't already - feel for how many bolt heads are already missing on the front manifold. Expect missing bolt heads to be broken bolts.
Yep also the rear manifold bolts don't tend to break as easy and the rear manifold doesn't tend to leak as much. It's not a curse - It's because the front manifold heats more.
---- Edit - bolt removal
My suggestion is to soak them with PB Blaster for a day before trying to take them off. Use a wrench that fits well. Make sure ALL the pressure you apply on the wrench is TURNING pressure only. To do this you need to use two hands on a socket wrench. One to hole the top of the wrench from moving, the other to apply the turning pressure. If the pressure you apply is part turning but also part twisting the head in a manner that isn't turning, expect the bolt head to more likely break off. The high temps of the exhaust cause the bolts to corrode apart. Don't be surprised to find the heads to be smaller than the 13mm they started as. Use only a 6 point socket. Use which ever size (12 mm or 7/16" or whatever) that fits TIGHT. If you have to pound the socket on a bit, that is good. If the heads are too gone expect to use a universal socket(see below). Put moderate pressure in the counter clockwise direction. Then reverse the direction and put pressure in the clockwise. Then apply again to remove. Keep on applying more and more pressure till either the bolt breaks or comes out.
The idea of this is the bolt stretches in a turning manner. So hopefully with each turn you will then to break a little bit and a little bit more free. This is also the procedure you want to use when removing bleeder bolts. With this procedure you can get 95% of the bleeders to come out without breaking. With this procedure you can get 50% of the exhaust manifold bolts out of the head without breaking.
[This message has been edited by phonedawgz (edited 12-27-2010).]
IP: Logged
09:46 PM
Dec 27th, 2010
82-T/A [At Work] Member
Posts: 24978 From: Florida USA Registered: Aug 2002
Honestly though, I would just get the FelPro gaskets which you can get from any local auto parts store. They are more suited for your application. The type-2 gaskets aren't so much a higher quality gasket, so much as they simply are for a totally different application. Just repeating what I've heard on the Samba, those gaskets are useful in the Bus because the thermal expansion on a Bus motor / exhaust manifolds / heat exchangers is much more significant than say a standard cast iron block with cast iron manifolds.
The most nerve-racking part here is that these bolts like to snap. Is your Fiero rusty AT ALL? If so, then I would really be careful with what you do. If you don't really have any rust on the Fiero, and the engine compartment is just dirty, then it's probably ok. If you snap bolts on the front, it's not big deal, you can drill them out. But if you snap them on the back, then you have to remove the cyl head. I don't want to scare you, but I just want you to be aware of it. You should know that if you start to turn a bolt, and it just doesn't feel right... then stop...
Quick jerking motions will help dislodge a stuck bolt... but slow constant pressure can allow you to just bend and twist it off.
As for porting it... there was a Herb Adams article written a number of years ago where he actually had the manifolds ported. He DYNOED the results on an otherwise totally stock car. He saw a gain of ~8hp by "hogging" the exhaust manifolds.
Here's an image that shows where you need to grind. Where that flat-head is pointing, that is where you need to grind down:
Basically, do what you can to grind away any restriction in that area. Having 8 more horsepower will mean that the engine has to use "less effort" to get moving, and will also mean that it's more efficient on the highway. This will improve acceleration, as well as fuel economy.
As for painting it, I've never had a lot of good luck painting stainless... but if you want to, it can't hurt. Just don't use a wrap because it can cause it to rust. As it stands though... the manifolds are stainless, so they don't NEED to be painted.
I would say if you have no experience in porting, then I would not do it on the only manifolds you have. Pratice on a spare set first. It is very easy to grind off too much material and then have a weak point for a crack to happen.
Soak the bolts/nuts with PB Blaster over night. Being careful, You can remove the rear cradle bolts and swing the rear of the cradle down for a bit more room to work on the rear manifold.
..Do not paint the manifolds,,not even VHT will last ,,the manifolds are stainless steel and get much hotter than cast iron manifolds,,Better to remove outer layer of grunge and try to restore original look,, these manifolds often glow red hot,,I have tried 3 times to paint with various hi temp ceramic paint.. the ceramic sprays will not work.. ..I used a combination of my own cleaned up bolts, some ace hardware 8.8 bolts and a few studs.. ..if you break ,snap bolt or stud in hole ,have mechanic garage repair, unless you are very experience gearhead,, this is very difficult, do not break easy out or extractor in broken bolt. ..If you have lived a pure chaste life,doing only good giving works walking in the foot steps of the gods,with generous tithing ,exhaust manifold bolt removal may be easy.all other sinners expect a few broken ..no penetrant will really work ,unless you jack car up enough for the fluid to flow downward,just take a rusty bolt place at same down angle as V6 fiero manifold and see how much penetrant flows upward,I try penetrant anyway?? .. the single best modification to any stock V6 fiero is to port the exhaust manifold ,,if you are unsure of your ability DO THIS MODIFICATION ANY WAY,,or pay one of the local Fiero fanatics to do it for you,, My V6 manifolds were 1/3 blocked,just look at the blockage in the above photo,, this is serious flowblock, the engine will have more power ,itwill havemore torque,it will run cooler,,it will get better gas milage,it will run smoother ,it will pull better into higher rpm,s If normal tool kit use a 1/2 inch socket & combination wrench this will be a tighter fit on a 13mm. ..ALLWAYS PORT THE STOCK V6 FIERO EXHAUST MANIFOLDS,,IF INEXPERIENCE REMOVE THE BLOCKAGE SHEET METAL STICKING UP IN PORT AND LEAVE WELD ALONE..THIS IS EASY TO DO,, YOU CAN DO IT WITH A REGULAR DRILL AND QUALITY GRINDING BIT..Yes ,it is time consuming to do ..the manifold blockage seriously interferes with flow ,,use search feature at left top of page to view post on porting exhaust manifolds.. ..ported exhaust manifolds can be purchase from the mall on this forum $75 to $100 shipped to you
[This message has been edited by uhlanstan (edited 12-27-2010).]
..I purchased 2 sets of ported manifolds neither was properly ported ,so if you buy manifolds ported by some one else,, they may need additional work to be properly ported,I ported mine to a work of art,smooooooth, & the results show it.
My car just keeps pulling hard into the redline
IP: Logged
11:35 AM
DLCLK87GT Member
Posts: 2717 From: South Jersey, USA Registered: Feb 2009
I looked at my exhaust manifolds today and found a few dissapointing things. First it is also leaking at the Y pipe connection, so I'll probably just replace those bolts and tighten them a bit more. But the little torx head on some of the bolts is missing and its just completely flush with the nut. So for that, I'll probably take the nut off first and then try to twist it out with some pliers.
Also, one more question, When removing the bolts, should I use the external torx socket (E7 I believe) and twist the bolts out? Or should I remove the nut first, and then use the socket to get 'em out? I think it would be best to t remove the bolts without removing the nut, because then if it does break, I could remove the nut and have a better chance getting it out with pliers.
Here's a picture to illustrate what I'm talking about, sorry for the size! (the middle bolt is the one with the torx head broken off
IP: Logged
09:03 PM
PFF
System Bot
phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
That's a stud. With that you want to heat the nut up till it's glowing red. The nut will then squeak and come off. It will burn you if you touch it too. Leave the stud in place for now. No need to remove it and it might break if you try.
IP: Logged
09:06 PM
phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
The reason it has the torx head is so they could install it at the factory. All you need to do is pull the nut off of the stud and the manifold will come off. Having the external nut to deal with means there is a 95% chance of you getting it off with no problems IF you heat it up cherry red first. Heating the nut will expand it on the threads plus will tend to make the rust that glues it together less sticky. The torch will also work wonders on your manifold to y-pipe bolts, and your exhaust to y-pipe bolts. Once you have them cherry red they will be loose enough to come off without more than average force.
The Oxygen doesn't compress. You will use 8 oxygen cylinders for every MAPP cyliner. Don't bother using propane instead of MAPP. The extra cost of the MAPP is WELL offset by the cost of the extra oxygen you use with the crappy propane fuel. This torch will get the metal red glowing hot. That is how hot you want the nut to be for it to come off easy. When the fasterners are external of the head it's ok just to heat the whole thing. Overall you want to heat the OUTSIDE fastener more than the inside one. That way you use the expansion to help get it free. It is a little tricky to use but isn't too bad once you get used to it. To heat up exhaust bolts it works quite well. To try and heat up bolts that screw into the heads is worthless. You will expand the bolt and tend to jam it into the head. The only thing you can do with the torch to help is to heat it up cherry red before, and then let it cool down. Hopefully the heating will cause some of the rust to unglue between the parts.
IP: Logged
09:19 PM
phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
A refillable gas bottle man torch is much less expensive to operate.
This disposable bottle boy torch is less to buy but more expensive to use. $60 ish to buy.
To remove your nuts you might use one or two bottles of oxygen. $7.00 each I think. Maybe $0.30 in Mapp gas. btw, always make sure your O2 is turned off so you don't waste a bottle of it.
I am cheap so I shut my torch off before I pick up my wrench. See how easy it comes off when it's cherry red?
You can braze with this 'boy torch' too btw.
[This message has been edited by phonedawgz (edited 12-27-2010).]
My dad has a refillable torch that I will probably use. Should I replace the studs then when I replace the gasket? They look pretty corroded, but I don't want them breaking off in the head.. hmmm...
IP: Logged
09:25 PM
phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
Unless the threads are so nasty that you can't use the stud in place, I'd lean towards leaving it in the head. Leave it in place and it can't braeak. After you drill out one or two broken bolts my guess is you will leave the studs in place.
IP: Logged
09:30 PM
phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
If you do remove the studs don't bother with the torx head. First choice is to put two nuts, one firmly tightened to the other, and then a wrench on them. Put the wrench on the inside nut, or both if you have a deep well, and unscrew it that way. Second way is to use a vice grips very tight on the stud. Work it back and forth. Once the studs have frozen themselfs in the head, the little torx head will do nothing but sheer off. They are really for installation only.
I'll probably be leaving them in then, drilling them out sounds like a real big pain. Should I still use the PB-Blaster the day before? I just don't want to end up lighting it on fire haha
IP: Logged
09:35 PM
phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
On the nuts and exhaust bolts? Yeah. My thougths have been that it's pretty worthless. That it burns off as soon as you get the metal halfway hot. However since a broken bolt or stud is such a PIA, I just do it anyways. Kinda like wearing your lucky packer boxers to the football game. You really suspect it doesn't make any difference however there is no way you would take the chance to find out you were wrong.
Yeah that stuff will burn when you get it hot. But the flame coming from the torch is a lot more of any worry than a little oil on the stud. Don't however squirt anything like oil on a hot hot stud. It will vaporize and could cause a flash of fire of some size.
[This message has been edited by phonedawgz (edited 12-27-2010).]
I'll probably be leaving them in then, drilling them out sounds like a real big pain. Should I still use the PB-Blaster the day before? I just don't want to end up lighting it on fire haha
Edit: Sorry, multiple post!
[This message has been edited by Nitsua (edited 12-27-2010).]
IP: Logged
09:40 PM
phonedawgz Member
Posts: 17091 From: Green Bay, WI USA Registered: Dec 2009
Be careful with the torch. You pretty much want two people, one who is dealing with heating and screwing, and the other who is a torch holder and/or heater. A regular flame you can pass your finger through and not burn your hand. That is NOT the case with a torch flame. Even just a quick brush of the flame across something can be VERY nasty. Also NEVER heat concrete with a torch. By that I mean never put a piece of metal on the garage floor and heat it. The concrete always has water in it. Once you get the floor hot enough it will explode out a divot of concrete into your face.
I'll probably be doing this wednesday or thursday then. I've got all my supplies, except the gasket which I had to order. Every part store around here didn't have one in stock
Be careful with the torch. You pretty much want two people, one who is dealing with heating and screwing, and the other who is a torch holder and/or heater. A regular flame you can pass your finger through and not burn your hand. That is NOT the case with a torch flame. Even just a quick brush of the flame across something can be VERY nasty. Also NEVER heat concrete with a torch. By that I mean never put a piece of metal on the garage floor and heat it. The concrete always has water in it. Once you get the floor hot enough it will explode out a divot of concrete into your face.
Okay, thanks. My dad's doing all the torching. He doesn't want me using it, but we'll see how it goes
I used the VW gaskets and double-nutted studs. I also ported, painted, and heat wrapped the manifolds. All this was with the engine out of the car. Be very careful with it still in the car. Consider swinging the cradle to give yourself more room if you have trouble. This involves removing the rear 2 cradle bolts and letting the cradle swing on the front 2 bolts. By gently dropping the rear of the cradle down a few inches the engine moves away from the firewall giving you more room to work. You have enough slack in the various hoses and cables. You have to remove the dogbone though.
BTW, I've only put about 5k miles on the car but they are hard miles running a turbo. So far the manifolds are holding up well.
[This message has been edited by Hudini (edited 12-27-2010).]
