Porting exhaust manifold

[Mopar_Nutz]

OK, I've got some spares around so how exactly do I go about porting it? Any areas I should focus on? Any I should stay away from? Also I've got a dremmel, what kinds of bits should I use? Anything else I should buy?

THanx, Ian

[silvershelby387]

make it smooth and get rid of anything that looks restrictive.also the manifold gets thinner the further in you go.dont get to crazy past the first inch in.

[Mopar_Nutz]

what would I use to smooth things out deeper in the runners?

[silvershelby387]

a dremil with a flex shaft.they are about 2ft long more than long enough.

[Mopar_Nutz]

Sweet, thanx. I'll hafta pick up that flexshaft. What kind of attatchment should I use? I guess nothing too harsh since I don't want to take too much off those areas I can't see...

[silvershelby387]

you can get carbide bits for them.exh manifolds are tough youll need it.

[Mopar_Nutz]

Right on. Thanx man. You are hereby crowned "King of the Ported Exhaust Manifold Thread"."thumbs up

[silvershelby387]

glad i could help

[spoon32]

Do you have the attachment number for the bit you use for porting?

[MM Racing]

FYI You will be there for ever if you are using a dremel. Much better with a carbide bit on a die grinder with air power. A better technique is try to achieve the same cross section through out the manifold. You dont want the port going up and down in size.

Go to www.mcmaster.com for carbide metal working bits or I believe summit sells them also, but they are 1/4" shank and not 1/8" like the Dremel.

[spoon32]

Well... I have one of the new 35000rpm dremels and not a die grinder. If anyone has the bit number for what they use for porting id appreciate it.

[93daytona]

I did mine with the grinder and air power. Still took me a couple hours I beliee. Came out pretty nice. I tried a dremel at first and I think it would have taken me 2 hours just to get 1 of the openings ported out.

[spoon32]

What bit did you use in the dremel?

[GovtContact]

THe problem with a dremel is that they are great high-speed tools, but they have very little balls, expecialy when it comes to removing metal from these manifolds.

I picked up a Milwalkee 7.5 Amp die grinder and a 5-pack of assorted die grinders,1/4" shank from Harbor Freight. (I know, I know, they sell some SH*T, but for $6, who cares). Porting was caried out with fair ease. After using the carbide cutters, I finished it off with a 80 grit flap wheel.

After your dremel is smoked from trying to port your manifold I recommend a die grinder (Electric or pneumatic). Dremels aren't built for the kind of work you are trying to do, their bearings and shaft weren't ment for heavy grinding.

Just my 2 cents. Let me know if you need replacement parts for your dremel...Got 3 of them with shot bearings and shafts!

[Tim_K]

I've ported several /6 iron cylinder heads and one set of V-8 Mopar iron heads with my Dremel. And one 2.2 aluminum head. Same Dremel, same flex shaft and cable.

All they ask is a little maintenance. Before doing a new head porting project, I take it apart and WD-40 the bearings as good as I can. The motor bearings look like they're sealed or something. But I soak them anyhow.

Then I grease and WD-40 the drive cable, and WD-40 the handset bushings.

And I clean the dust out of the Dremel motor.

No problems so far.

Porting aluminum heads is an absolute pleasure compared to doing iron heads. Iron heads are always dirty, no matter how much you clean and hot tank them. Once you get past the top layer of dirt, aluminum heads are totally clean and easy to port and shape. Aluminum heads come off in larger pieces, while iron heads grind into a fine powder. Just don't go too far with it.