Ok, maybe this is a no brainer to some of you, but I don't know the answer here.... I want to polish my exhaust manifolds to clean up the engine bay, I figure I'll start off with the dremel to get rid of the major crap and finish them off by hand.

My dad suggested getting a spare set to work on if I can get them cheap.

I haven't a clue what j/y's around here might charge for some manifolds, but my first question would be, do the manifolds have to be swapped from the exact same model? It seems like the 2.8 is a much more common v6, due to more production years, but I have the 3.1? Did the manifolds change? I assume the v8 manifolds won't work because of the bigger block?

Mathius

 

V8 definetly won't work. The 2.8/3.1 should be the same. The 3.4 may even be the same, but don't quote me on that. Just take a look at your current manifolds, and then hit the boneyard to see what they'd charge. I wouldn't think more than $30-$50.

 

I also have the 3.1, and I think that they are the same manifolds as the 2.8. Be sure to check the mounting position and bolt location of the EGR valve, which will be on the passenger's side manifold. The bolt holes to mount them to the block will be the same, but I am not sure about that EGR valve.

 

I belive you would want a more current set of a MPFI and not a carb.

My 3.4l manifolds look almost identical to the 3.1l Also, the 3.4l has some nice shinny aluminum "sheilds" where the 3.1l and 2.8l does not.

 

The 3.4 wasn't offered until '93, right?

Mathius

 

Correct,

85-89/90 is 2.8
90-92 3.1
93-95 3.4

 

Polishing exhaust manifolds is a real PITA! Think polishing aluminum is time consuming? Cast iron is LOTS of fun, esp since they're usually rust pitted. Redraif and I did her exhaust manifolds and had them coated (necessary, or they'll rust immediately). Go for it if you have plenty of time! We're switching her car to longtube headers soon, so maybe she would sell you hers already polished and coated...PM her if you're interested.

Check out her polishing page:


http://www.cardomain.com/member_page...191601&page=14

 

Thats if we can get those headers to fit...

All I can say is it takes forever. A spare set is the way to go. We used a dremel and grinding stones. Also scothbrite lock discs on a die grinder. Don't bother with sandpaper. Just get is relatively smooth and the coating with handle the rest... And Coating is a must after. Wear gloves & a face shield. Safety goggles are not enough. My eyes got metal flakes in them, trust me its NO fun!

I'm not so sure what I will do with mine after we get the headers on...

 

I can only say this.
1. It truly is a waste of timie.
THAT SAID
Here's why.
These manifolds HAVE A NASTY HABIT OF CRACKING
They are "fragile".
Options for nice looking which I believe is what ya truly want.
www.eastwood.com
They sell very very good manifold coatings in various shades.
Apply while still on car.
Other suggestions
The 3.4 manifolds have aluminum shield that also acts as the gasket.
YET try to find those cheap!
Option find a spare set of any 60* RWD V-6 and paint as Eastwood suggests AFTER YOU MEDIA BLAST THAT SPARE SET CLEAN!
Wisest is to check out Eastwood website for exhaust manifold paint. Not too expensive & applies quite easy.
BUT SERIOUS these manifolds crack real easy!
I've replaced BOTH my original nmanifolds due to previous owner having them crack.
Now I have the 3.4 manifolds with the shields over them & big deal, I only care abut the car running real strong, cheap & reliable for my Wife & my 2 1/2 year old Son.
I apply my talents to the other rides I own.
Check out Eastwood, you may be very pleased with that manifold paint solution.

 

I might be interested in her pre-polished set if it doesn't cost an arm and a leg, Joe. Not saying you'd cheat me or anything, I just don't know what they run for or what you had to pay to have them coated, it just might be more than I want to spend.

I was already planning on using a dremel. I didn't realize it was that difficult, but I was gonna use the dremel to blast off the major bits and smooth it a bit by hand.

I wasn't going to powerdercoat them either, I was going to just use engine enamel. Is this a waste of time? Anyone know what it costs to have manifolds powerdercoated?

Mathius

 

Engine enamel will not hold up to the heat... I tried. it turned ashy and then promptly rusted again.

When I smoothed mine I was very careful to only hit the rough stuff. Inside, I only knocked down the casting lines. Nothing heavy. I also heard they crack.. So I did it to a spare pair...
They have held up for a year w/o cracking.

Ceramic Coating was $100.00...

Polishing...I would not have a clue how to value that....

 

Do you think even the "High Heat" stuff Duplicolor makes would not work?

Mathius

 

I can say from experience that PREP WORKS MAKES THE DIFFERENCE.
I would trust the Eastwood stuff more than anyone other stuff as I've seen those "others" results. And I have seen the Eastwood results, quite impressive.
You really seek a spare pair or a set already done.

 

While fixing an exhaust leak about a year and a half ago, we sprayed one of the manifolds with Duplicolor high heat red, planning to do the other side later. By the time she got from my house to hers, it had turned pinkish white and was flaking off. Eastwood makes cast iron,black, and stainless steel paint that will hold up, if you want a more stock look that will last. Its the only paint-on product I have seen that is decent. If you can find anyone that still sells CermaChrome (do it yourself ceramic coating, like Jet hot), you could spray them with an airbrush and cure them in an oven. Aircraft Spruce & Specialty lists it in their catalog still (Summit used to), but I haven't checked to see if they still have it.

http://www.aircraftspruce.com/index.php