Smoothed my exhaust manifolds, wondering if there is a better way...

I've been wanting to get a set of the early Vette 2 1/2" Ramshorns and since they're impossible to find I decided to break down and buy the reproduction ones from Speedway motors. Not a bad price at $65 each, but as you can see th castings were really rough. I wasn't about to bolt them on my 327 the way they looked out of the box, so I smoothed them. Took about 3 hours on the first one, but part of that time was spent cutting the alternator mount off and smoothing that area out so I didn't look like it was even there (aside from the bolt hole).

I used a smallish grinding stone on the end of my air die grinder and then used a flap wheel to take as much of the un-eveness out. It's still a little rough and I could spend 3 more hours making it mirror smooth, but not sure it's worth all that effort.

Is there an easier or better way to do this?

 

Not sure-but that looks pretty damn good!

 

looks good but maybe one of those flapper disc things might speed it up?

 

i just bought a set too and i agree with you that they are VERY rough. the Speedway ones are relabeled Dorman part # 674-504 left and 674-503 right

 

you done good , dont want them looking to 'over' done..........

 

x2.

 

nice work its well worth the time. they look 100% better

 

If you've got good control over your tools, you can start with a 4 1/2" grinder with a stone on it. Then progress to a flap disc on the same grinder.
But you have to be on your game with a tool that can do that much work so quickly. You can ruin a piece in a split second, if you're not careful!
Then go into your hard to get spots with the die grinder and small stones (or different shaped carbide burrs), and cartridge rolls to smooth them out. I also like the tiny 2" flap discs for my die grinder to get into small areas and clean them up fast.
If you're going to coat it anyway, you really dont' need to go past a 180-220 grit finish.

 

That's exactly how I did mine. Couple of hours on each one, and done!
BTW, even when wearing a mask, you'll be blowing black crap out of your nose for days!

 

Nice job. I have been on the fence on buying a set. After seeing this it may just push me to buy some.

 

awesome work...i'm looking at doing the same thing real soon, although here's a dumb question, if you buy them through dorman can't you just buy the one's without the alt bracket to save the time cutting it off?

 

be sure that the old carb heat tube in manifold is blocked off before installing-they look plenty good now-some time look at the Eastwood site for different grinding tools, etc.

 

I used a sharp chisel and a mid-sized hammer on some truck manifolds, to cut the untapped air tube bosses out of the ports. It worked really well, if you cut in shallow, and just let the metal roll up at the end of the chisel. Seemed faster than the grinding stone, but took more labor.

 

Bandsaw for bulk removal, 36-grit flap disc on 4-1/2" angle grinder until smooth, sandblast to restore rough finish.

 

Looks good

 

Nice,but what about the inside?

 

Have you tried a belt sander?

 

The better way for me was finding a set at a swap meet already done, I didn't do them but I appreciate all the work put into them, and you can see it will be worth your effort, these where also porcelain coated the guy I got them from traded and said they where in a box of junk. Keep grinding away.

 

If you are, I'd think seriously about getting a better mask. That stuff is BAD for your lungs.

 

I just ground on mine ... until I got them smooth. I also ported the insides smooth as far as my tools would reach. I had them JET-HOT coated and they look the same after 5 thousand miles. The entire exhaust is coated ... from the manifolds to the end of the tail pipes.

.

 

I did it the way chopolds said. 4" grinder, then flap discs, followed by a die grinder with stones then rolls. Worked fine, but it is alot of work. Don't know of another way to do it with significantly less work, other than paying some one else to do it.

 

Both of yours are looking a lot nicer than mine, maybe I need to do a little more work... Thanks for posting the pics.

 

Where did you send them to get coated? I have to buy a new pair to replace my originals and I like this, looks slick! Also, if you don't mind my asking, what was the damage?

 

As stated earlier, if you get black boogers from metal polishing even after wearing a mask, it wasn't fitting right, and might as well not have been there. I do polishing for a living and I have clean snot at the end of the day using regular disposable dust masks.

We use 3M 8210 N95 currently, but any decent mask will work. These have rubber band straps, but I prefer the stretchy fabric version better. Some versions have a one way flapper valve that prevents a lot of humidity buildup, I like those too.

As far as getting a quicker easier way to polish them, the better variety of abrasive tools, the better. Experience will make things go faster and safer too, but that takes a while.

I have a set of manifolds from a 74 'vette that I was thinking of polishing up and nickel plating, documenting the whole process; maybe someday.

 

Nickel would look cool! Ws wondering how tight you think those masks should be worn? Should you have lines in your face after wearing them?

 

Those are nice.

I did a set a long time ago and used the Eastwood exhaust coating. You don't want them too smooth or nothing will stick to them. Even these jet coated ones were probably sand blasted prior to spraying.

 

Harbor Freight sells emery cloth in 1" by 150' strips for about 5-6 dollars. You can use it like a shoe shine rag. Also good for hand work.

I like 80 grit for most of my work. It is a good compromise between aggressive material removal and control.

 

What?

Iron and carbon? Maybe if you were drowning in the stuff, but those are both naturally-occuring in your body anyway

 

Sure, they are, but they are supposed to go in via your digestive tract, with food food, not via your lungs.

The only form of Iron, at that, the body can absorb is Fe²⁺. I'll give you a hint, this ain't what is coming off of your manifold when you grind it.

I'll skip the lecture on Black Lung Disease. You can look that one up yourself.

 

OK, you guys convinced me...I went out and bought a good dust mask.
You can stop talking about my boogers now.