well i know i only have a v6 and hope this stays in high end discution because it is for me (for now)

and besides all head porting is the basicly the same anyhow

are there any how to guides on the internet? to pocket port or do any of you have good advice?

i have read a few books on it as well.

 

good luck, i have seen this q posted quite a few times, and have yet to get a real answer. at most i have heard complaints of the pics posted at the standard abrasives site, but when asked, no one on this board could give a real answer to what was wrong with the pic. they all said "it sucks" but refused to say why. ?????

all i can think of is that no one will say, cause that's how they make money.

my suggestion, find a head guy where you live, buy lots of beer, so he's nice and drunk and talkative, then pump him for info.

 

go to the School of Automotive Machinists in Houston TX, thats probably your best bet if you want to learn something.

 

"go to the School of Automotive Machinists in Houston TX, thats probably your best bet if you want to learn something."

I would agree if you are wanting to get into this field. It is in my opinion the best school in the automotive field. It is a school that is focused on race engines only and the only one of its kind.

Anyways, unless you are wanting to really learn about this stuff, it is best just to save up some money and take your heads to a professional. I develop cylinder heads for a living and there is way more involved than anybody could write in any book, let alone respond back in some forum. It is an artform. Let the pro's do what they do.

Nick

 

One of David Vizards books covers the subject. It I remember right it's "How to Build & Modify Chevrolet Small-Block V-8 Cylinder Heads".

Rich Krause

 

Good reading for anyone wanting to DIY.

Rich Krause

 

http://shopping.capelinks.com/amazon...879385472.html

 

Best thing to do, jump right into it. That's what I did. I looked at the standard abrasives site, and did a few quick searches on yahoo. Taking your time is the key.

I used a GM gasket and matched it with a dremel tool, it was much easier to use the dremel because I could get very precise with it. I bought a bit for a die grinder from the tool guy that comes by my work and used that to remove material in the runners, bowls and some of the combustion chambers. Then I finished it all up with some assorted sandpaper rolls on the die grinder.

All I did was try to make as straight a shot possible for the air to get to the intake valve(but don't mess with the port floor much), try to unshroud the intake valve(the exhaust valve seemed ok) in the combustion chamber, and then opened up the exhaust runner some. It's really hard to explain which is why I say just do it, you'll be able to understand when you get in there.

I know these aren't the best pics, but they'll get you started-

http://www.tennesspeed.net/gallery/s...cat=500&page=1

http://www.tennesspeed.net/gallery/s...cat=500&page=1

http://www.tennesspeed.net/gallery/s...cat=500&page=1

Edit: those pics should come up, if not I'll link them from somewhere else.

 

I agree fully on Nick on both these points.

Head porting is something I have never learned, but one thing I have learned is that you work with very good people who specialze in this. Knowing what you would like from them is part of engine building, but getting it out of the heads is what guys like this do.

Bret

 

I'd recommend purchasing the Chevrolet Power Manual from Gm. It has a section on 60 degree V-6's. I have the 6th edition, which mainly has info on the 2.8, but most of it applies to the 3.4. A newer version may get into the 3.4. It doesn't have a lot of porting instructions, but it's relatively inexpensive, and the general info throughout the book makes it worth buying.
A few years back, I did several 3.4 performance engines, which included some cylinder head developement. One important thing to keep in mind is that these heads have a flat valve angle, meaning that the valve stem is paralell to the bore. I tried many different shapes of valves, and the stock "tulip" shape flows the best. In a 23 degree SBC head, when the valve reaches a certain amount of lift, some of the mixture begins to flow across the face of the valve towards the center of the bore. With the flat valve angle of the 3.4, the mixture flows around the valve regardless of the amount of lift. For this reason, unshrouding the valves in the combustion chamber is also important. Per GM's recommendation, do not remove the vane on the floor of the runner. A good valve job, some bowl blending, and a spring upgrade will probably provide enough improvement to outflow the intake.
Good luck !

 

First off I certainly wouldnt listen to anyone who says just to jump in and do it. Anyone who would say that obviously has no idea what they are talking about. There is way more to getting heads to flow than you think. If you dont have a flow bench then you have no idea what you are doing. It is easy to do a little grinding and kill a port. If you do a lot of research first you might be able to help your port. But if you dont have access to a flow bench or someone who is actually a professional that is willing to help you then there is no way to know if you helped it or hurt it.. If you care at all about your engine then you should let a professional do it.

 

I don't completely agree with the concept that head porting is something you absolutely must leave to a pro. While I agree that you need to have the access to a flow bench to make sense out of what you are doing, it all depends on your goals. If you are starting with an expensive set of heads and want the best results possible, you had better go to a pro. But you can get a set of LT1 heads for $250-300, so it's not a catastrophe if you screw up. And if your goals are relatively modest, especially if you have someone to give you some help, you may achieve your goals and learn something in the process. As "aggiez28" said, you have to learn somehow.

That said, I take my heads to a pro. But my goals and situation may be very different than yours. And keep in mind, if you read many of my posts, you may remember that I am usually the first guy to say "take it to a pro".

Rich Krause

 

Now the motor in question I know squat about the heads but on a SBC with a regular 23 deg head that has been around for 48 years and has had basicly the same design of head from the factory on, I do beleive that a amatuer can do basic mods and get good results. The average Joe has enough material (reading and pictures) out there where he could do a decent job if he took his time and followed the outlines to a T. The Small blcok chevy heads are no new mystery head or nothing like that, as Rich said a set of cheap heads is nothing to cry about if you make a mistake, if its a 12 second car you probably wont miss 5 to 8 cfm like a high end racer would. Now of course if you want really good results go with the pros, but if you just want to do the bowls and some blending "jump right in" with some research, and do it. Do you think Arnie Beswick had a flowbench? What about Don Prudhomme? They didnt get flowbenches until they got big. Arnie started porting heads on his M&M tractor!!!

 

I may have came off wrong on my last post. I do agree that if you want to practice with a grinder on a junk set of heads then go for it. The only problem is that you arent really learning anything that way. Before I gained access to a Flow Bench I did as much research on the topic as I could and even tried porting some heads myself, and did make some improvements on a pair and not so much on some other sets I did. When I finally got on a flowbench I realized how much I really didnt know and found that some of the common first steps in porting that some books recommend such as bowl blending, guide narrowing and chamber unshrouding can sometimes hurt flow unless you know what other areas to modify to make the port work. I am all for the do it yourselfer, I was just saying that if you want to get good results then do some research and take the heads to a pro that has a good reputation. However before you do take the heads to a pro take take cross section, and radius measurements of the entire port and then reexamine the heads when you get them back. This might help you learn something.

 

Good point, I sent a set of heads off for a pro job here locally that has a good rep, (Buddy Rice in OKC ,Ok) and I measured the throat , bowls etc. I duplicated this on a set of 041s I had lying around and I actually got really good results, but the first set of heads I tried porting (stock 305 LB9 heads) I made mincemeat of and they were worth nothing more than scrap weight. I did learn alot though and LB9 heads are junk anyways so I was out nothing. The book that was mentioned earlier by David Vizzard does show you how to build a home made flowbench.