Heads

[3400-95-Modified]

I used a dremel with a flexible extension and some carbide bits, and cross buff bits and so on...... Worked fine for me.

[SappySE107]

I wasn't trying to ridicule you, sorry.

[2.8/3400 1985 Camaro]

Those iron heads are going to kill your dremel... One thing I know of is to keep the "fin" that is inside the head. You can clean it up some, but don't get rid of it, as that will kill any improvements you made otherwise.

For N/A that is definitely true, though I think that for turbocharing it is beneficial to remove because air is being forced in, my understanding of porting is that, for N/A applications, its all about flow velocity, whereas boosted apps, its all about flow vollume/quantity.

[Flying Jester]

I'm not under any illusions that going medieval on the heads with a dremel will magically give me 200 HP, but since I've got so many spare heads I figured I'd play around with it. I've done a couple (it's not really a dremel, it's a pneumatic grindy thing that apparently can hold its own with an iron head) I've tried them, and at least they seem as good as the stock version. And on the first one, I think I cut out the fin.

Maybe after 25 years of dirt, blood, and mud the engine isn't as sensitive as it once was...

[86FieroSEv6]

From what I can see in your pic's, I believe the "notches" you are referring to are the machined undercuts from the hardened valve seat installation operations.

[pocket-rocket]

From what I can see in your pic's, I believe the "notches" you are referring to are the machined undercuts from the hardened valve seat installation operations.

I'm no head pro, but I concur.

[Rootie524]

so they can be grinded out they no longer serve an important purpose?

[pocket-rocket]

Being N/A I would smooth them out, not completely get rid of them. Otherwise velocity can be dropped if the ports aren't choking your engine right now. At least that's how it makes sense in my melon.

[3400-95-Modified]

I wasn't trying to ridicule you, sorry.

I wasn't taking it as that, I was just simply saying that its true, a lot of people do home porting work using a dremel and the flexible end to get into the ports, and for most that works out just fine, for two reasons, they are typically only doing one set of heads so time is not an issue, and the dremel doesn't have to last that long.

I can definitely see how a full blown electric die grinders would work for you and help turn around time and probably outlive a dremel any day.. but if you ask me they seem a bit large and bulky to do the work, especially when your starting out. I would rather work with something that takes much more effort to f-up rather than a tool that you could blow through to a water jacket in no time.

So really I agree with both sides. If you have time, and it is your first time then a smaller rotary tool may suite you well, but if you are turning these things around for profit and you know exactly where and how much to cut, then something a bit larger and with a bit more power/longevity will suite you better.

[SappySE107]

It is more difficult to do a good job with smaller bits. Consistancy is important. You can get into smaller areas with those small bits, but that detail work nets you the least return on time. For the easy to get to areas, it is more difficult to be consistant on the port itself, let alone port to port. I started with a dremel and I have ruined plenty of heads on accident and on purpose. I will never recommend a dremel to anyone that wants to port, professionally or not.

[86FieroSEv6]

One of the methods used by pros to maintain consistency from head to head is to make port templates once you have achieved a good setup. These templates are made to the shape at different depths in the port so you can check the shape as you go. They are pieces of sheet metal with a heavy wire attached so they can be inserted in the port. The templates are marked for proper order based on position in the port.



Damn . . . . gave up another speed secret . . . . .

[Superdave]

I think the perception of porting is different between those who do it a lot and those who have done light porting with a dremel. I have no doubt that 3400-95-Modified's heads are better than stock, he did a very nice job however when a person does a "competition" port job like Ben, John and myself there is quite a bit more to the process. I think Ben can vouch for the amount of material removed from the ports on my 3500 heads.

I've got 2 hours of porting into just a 3500 UIM and LIM that are on my bench, probably another 6-8 will go into the heads. That's with an air die grinder and a nice set of bits. I'll also probably spend another hour or 2 working with them on the flow bench to match all the ports and give the customer final numbers. It is not an easy process.

[pocket-rocket]

I started with a dremel and I have ruined plenty of heads on accident and on purpose. I will never recommend a dremel to anyone that wants to port, professionally or not.

I think by the time the heads for the 91 were done, both of our Dremels were screaming for mercy, new bearings and brushes...

[SappySE107]

Yeah, they didn't like all that work/pressure.

x2 with what Dave said.

[3400-95-Modified]

x2 with what Dave said.

Dave just said it better than I did... LMAO

I don't expect my heads to be as good as your's but right now thats all I could muster... SO maybe next year when I grab another 3500 and 3400, or just a 3500, I can have a professional job done.