Well I guess that that answers my question on what to do about that. I've heard both arguements, but dont really know what one to believe. I think that I might do like a cross between polishing and not polishing, because you can tell that there is certain areas where the fuel goes and other areas where it doesnt. Besides that when it is ported that doesnt mean that its polished, you just use a more coarse bit.

Yea your not supposed to polish the intake too smooth, the rough air flow keeps the fuel suspended, the curves are kinda like a centifuge, the fuel will be heavyer and flung onto the walls unless there is turbulent air there to keep it in suspension.

As far as negative comments . You really should have them flow tested, Not only so we can know if its worth it, but when I was asking around a lot of knowlegeable people told me I probably shouldnt mess with the heads unless I had access to a flowbench because unless I could verify I had the same exact airflow to each cyl, I could cause some major problems. I dont know how much it could really hurt, but im sure it would be less than optimal.

.

[This message has been edited by Dave Gunsul (edited 03-29-2006).]

there is no way they were even close to equal from the factory. due to flaws in the casting, some ports had huge ledges in them where they stopped machining for the valve seats and other ports had no machining and actually had empty pockets from not enough metal or possible air pockets in the mold. i seriously doubt they could be any more mismatched than they were from the factory. As far as polishing the intake, i have my opinion and i'm not even going to try and change the opinion anyone else, but i will say that i cleaned up the intake ports on my heads and am not worried about it. it's funny that people will complain about fuel puddling on a batch fire system and that the problem is minimized with sequential injection but when the topic changes to porting the intake everybody freaks out about fuel puddling again. i told Jeff to stop posting in this thread, you just can't win. it's better to keep things to yourself and enjoy the beneifits.

FYI, on the northstars, the best intake gains are seen when you turn the intake port divider into a knife edge... Something to think about..

So far, so good. Now you see why porting costs so much to have done - it really is time intensive

As for the flow matching, well that is why im doing everything with the pocess that I am. im trying to do one thing at a time to each port on each head with one example port to go off of on the exhaust since it was such a radical change. Maybe it wont work, and I honestly really do believe that I'll loose quite a bit of low end with what im doing to the exhaust side because the velocity of the gasses is going to be significantly less, so unless there is more air flowing (ala higher rpms) I think I might loose. But that isnt a concern for me because i really REALLY want more top end. I feel that the overall improvements that im making elsewhere and the increased compression when i get the heads resurfaced should make up for some of it. Also, I have done some more research on the porting last night and after reviewing a porting article ( http://www.sa-motorsports.com/diyport.shtm ) again I am going to go ahead and port out the intake side as per thier advice. What they had to say about it was that you should keep it to 80 grit and no higher to keep the fuel atomization at the best. So thats what im going to do. If anyone wants to dispute that its fine, but do it after reading their article with thier results.

I am considering not updating this thread anymore, it seems that the most that I get out of it is negative feedback. Read Dave Gunsuls post above, that is really what this thread is about. If someone wants them flow tested, send me the money and I'll do it, but otherwise im not going to unless i can get it done for dirt cheap or free by the machine shop that I go through to get the valve job and head resurfacing done.

As someone interested in the LQ1 (for after I actually GET a Fiero, at least), I just wanted to say that I find this thread very interesting and that I hope you continue updating. I'm sure I'm not the only person that has been watching silently and taking notes. Thank you for what you're doing.

[This message has been edited by Fiero Brick (edited 01-04-2006).]

Hey don't stop now! I think this is a great thread. It's really helping me to know what I will be getting into when I do mine. I agree with Dave, this is all about trying something on your own with a linited budget and improving what you already have.

Don't worry about the negative comments and criticisms, I don't see them posting pictures and info on the heads that they have ported on their own either.

Nolan

Jeff, I wouldnt listen to those telling you to get these flow tested. You know how cheap Fiero owners are, do you really think they would get them flow tested? I didnt get my 4.9 heads I ported flow tested and it sure as hell didnt slow my engine down. Besides, I'll bet the factory castings dont flow 100% the same to each cylinder on ANY GM car.

Please don't stop now...I'm going to be doing this soon also, and this is going to help out alot.

Justin

allrighty, since it seems that there is sufficient interest, i'll continue to update the thread, starting with this post....

I worked on the heads some more tonight. I wanted to get the other exhaust ports finished but I lost interest in the exhaust side before finishing them completely, so I guess that we'll just have to wait on that. They are almost done though, I just have to complete the short side of the radi, which is not the easiest part in any way what-so-ever. Oh well! Instead of finishing them up I did the last 6 intake bowls. So as it sits, one of the heads has all 3 of the exhaust ports completely ported (not polished yet) and the bowls on the intake side are finished as well. The other head has everything but the short side of the radi ported on the exhaust side (not polished at all either) and the bowls on the intake ports on that side also done. Without further ado, heres some pictures...

just a few pictures of where the heads are at so far...

this is the exhaust side that is not completed yet, look at the top part of the ports and compare to the next picture...

comparison shot (completed side)

heres a shot of one of the intake bowls that I did today. I have just been keeping it simple with them so far, but im sure that i will be smoothing them out quite a bit more sooner or later.

continued on next post...

You're not done yet?

No James, Im not, would you like to come over and help to give you something to do instead of b*tching that Im not done yet? Oh wait, you cant come to Wisconsin, so nevermind....

[This message has been edited by fieromadman (edited 01-05-2006).]

quote Originally posted by FieroMaster88: .... Besides, I'll bet the factory castings dont flow 100% the same to each cylinder on ANY GM car.

Please keep going Jeff and ignore the discouraging words.
I want to see your success progress!!
.
I remember a Hot Rod article decades of full moons ago where they used a spark plug/pressure sender to
measure running compression and combustion pressures.
Their remark was about how meaningless the test was because the graph was consistently inconsistent.
You have all sorts of pressure waves contributing to the mayhem in an intake,
sorta like the water's surface in a pool, and the intake charge varies widely
from cycle to cycle on the same cylinder and between cylinders.
=>> I AM NOT saying porting doesn't help. The average charge goes up, but the output from one power stroke to the next are not the same.
Their main intent was to check if cc'ing a head really mattered much for a street motor. I wish I could remember at what percent it was worthwhile.

Makes me wonder if they ever did the test with a boosted motor. I'll have to look into that.
Got my own curiosity up now.
TG

[This message has been edited by TennT (edited 01-06-2006).]

fieromaster88 was not the one being discouraging, he was arguing with me because everyone was saying that i would damage the engine if they didnt flow equally and he was saying that its not like they flow equally anyhow. James (fieromaster88) is a friend of mine. It was what other people were saying about how this is worthless unless i flowbench it and make sure that they are equal that was discouraging me. I dont intend on giving up on this thread just because if nothing else i want it for my documentation in case I do another head, i can look back at what i did and learn or improve on it. Besides that, I'd really like to proove all the naysayers wrong when this is all said and done. I might flow test them just for the hell of it because I really cannot see thier overall flow going down after the port work. BUT, if I am wrong, i will swallow my pride and also tell everyone. I plan on working on them some more tonight, so stay tuned....
Edit; typo

[This message has been edited by fieromadman (edited 01-06-2006).]

Hey MADMAN check this out. I figured out a way to use the cartridge rolls on the crossbuff arbor. This helps get the roll deeper than with just the normal arbor.

first screw the threaded portion into the long arbor

Then screw the roll onto the threaded section.

After it's all together spin the setup to make sure it doesn't wobble all crazy. If it does you can kinda tweek the cartridge roll until it spins nice and straight.

------------------
HARDCORE SBC CRONIE AND PROUD OF IT ! GOT TQ ?

I dont have any crossbuff arbors yet actually, ive been looking into seeing where i can get them for the cheapest. I have two different length mandrels though so i pretty much have what i need as far as reach goes. Im just going to need something for the polishing. Where did you get your cross buff and accesories from? Standard Abrasives??

------------------

--180* t-stat, (cam degrees) 1.5 degree intake advance and 5 degree exhaust retard, ported lower intake, FFP pulley, A/C Idler, flowmaster exhaust, EGR delete, K&N filter, chip-- --Check out the Fiero Kingdom!--

The kit i have is a Standard abrasives deluxe porting kit. I got it from summit racing p/n SAI-260001 . There are a couple of bits in the kit i don't use but all in all it's worth the $$$$ . The cross buffs are kinda big for some ports ,but they can be cut down to a smaller diameter the each all the nooks and crannies. Just remember when your polishing with the cross buffs , use WD-40 or PB blaster as a lube. If you don't the buffs wear out and fly apart

..

[This message has been edited by Dave Gunsul (edited 03-29-2006).]

Well I finally got my heads worked on again. And no Dave, I didnt use shoes, but I used my glasses.

Well I finished up the porting of the exhaust sides today. Now all that I have to do on the exhaust side is polish them and Im going to have to get some cross-buffs for that. After i finished up the porting of the exhaust side I went on the intake. I dicided that it would be a good thing to smoothen out the bowl area a little more than what i did, so i went ahead and did that. Then I worked on the casting flaws and knife edging of the intake side.

heres some pictures:

So the exhaust side was done, the short side of the radius recieved the majority of the work today..

heres both heads with the exhaust side done...

before i knife edged the middle divider...

heres some pictures of the casting flaws/where they used to be..

next post...

continued from previous post...

where the bowls were all refined...

looking better... the middle is knife edged finally.. looks much better.

this head is pretty much at the stage in all ports. the other one i have not really started on the intake side except for the bowls.

Thats it for tonight... let me know if anyone has any questions..

------------------

--180* t-stat, (cam degrees) 1.5 degree intake advance and 5 degree exhaust retard, ported lower intake, FFP pulley, A/C Idler, flowmaster exhaust, EGR delete, K&N filter, chip-- --Check out the Fiero Kingdom!--

quote Originally posted by fieromadman: Thats it for tonight... let me know if anyone has any questions..

Yah, do you have flow numbers yet? If not when do you plan on having them? It'll be interesting to see how they compare to stock.

------------------

"all pushrod motor are better than the dohc because it has less rotational mass"
-rick17, MyMonte member, owner of a 3100 Monte Carlo LS

Hey, they are looking great. Thanks again for doing this.

Nolan

No I dont have any flow numbers yet. their not done yet so it wouldnt make much sense to get them flowed, besides I dont have a flowbench either so when I do get them flowed it will be when Im all done because im not going to make multiple trips to get them flowed.

Thanks for the complement!

Worked on the heads some more tonight....

Im at the point now where I have to make the decision as to how far I want to take the intake side. I could go for really messing with the short side of the radius or just leave it alone for the most part. According to most of the head porting guides that I have read, modifing the short side of the radius makes a big difference. These dont look too terrible although the angle is kinda severe, but at least there isnt a ledge or anything.

As it stands I could be pretty much completely done with one head (minus the polishing of the exhaust side which I still need to get the bits for). If I want to modify the short side of the radius though, that would be another thing. And for the pics (now up to 78 pictures in this thread!):

The first thing that i really did toda was work on "gasket matching the intake side" which really is more of a rough estimate than a true match because of the way that the intake gaskets are. in this picture you can see where the fuel cleaned the area where the port overlapped the gasket. I want to get rid of this problem soo....

So I put a used gasket on there to try and match it but its really hard to tell what is and what isnt actually contacting the gasket. i guess that i just figured that i should mark off the areas that are showing with a permanat market and take care of that because there is a good chance that it wouldnt ever be touching any of the gaskets.

Although its not much I think that it will help a little and its better than nothing.

and here it is after the "gasket matching":

continued on next post...

Wow, talk about a huge intake port hahaha. The poor old 2.8 just doesn't get any love

from here, lookin good!

Hey madman I would leave the short side radius . If you knock it down you'll make a sharper turn for the air as it travels down the port to the valve. That sharp turn will hinder the flow and create turbulance if it's cut down to far. Thats just my opinion though . Anyway it's lookin good keep it up !

------------------
HARDCORE SBC CRONIE AND PROUD OF IT ! GOT TQ ?

[This message has been edited by FIEROPHREK (edited 01-25-2006).]

well actually, im going to disagree with that statement.. Heres a view of an actual 91-95 3.4 dohc cyl head that has been chopped apart: (original image courtesy of www.60degreev6.com photo gallery)

If you look at the short side of the radius it has a kinda harsh slope to it stock, what i would do is i would take down the material to approximatly make the angle that is shown witht he red line thus making a less severe angle and causing less turbulance. Maybe im not quite understanding what you are trying to tell me but i think that creating less of an angle there would create a better flow into the valve.

Well now that i see this awsome cut-away i'll say go for it ! It looks like the red line would make a great radius.

------------------
HARDCORE SBC CRONIE AND PROUD OF IT ! GOT TQ ?

Well it looks like I gotta do a little bit more work on the intake side then! Prolly do that tomorrow.

and yes, the cutaways are definatly nice to have handy!

So, hows the porting coming? youve got me thinking about the DOHC swap, so i want to see how this improves things for you.

Wow, its been a while since I posted in here.. Ive been really busy working and working on other projects/other peoples projects. I was just going to bump this so its doesnt get archived because I still am going to finish them and post results. I havent gotten any farther since this post. I hope to get around to them this weekend though because I want to send them off to be machined within a few weeks. There really isnt too much left to do anyhow. They will be going on this spring still, I promise!! Hopefully I can get some flow numbers as well.

-Jeff

------------------

--180* t-stat, (cam degrees) 1.5 degree intake advance and 5 degree exhaust retard, ported lower intake, FFP pulley, A/C Idler, flowmaster exhaust, EGR delete, K&N filter, chip-- --Check out the Fiero Kingdom!--

Hey get crackin' I wanna see how these turn out!

Nolan

well, I must say you took the negative comments well. good for you. you WILL see a gain from this. cleaning up the heads on any motor will help the flow. each motor and head set has it;s own quirks, bad spots, and with some the best you can do is make them less miserable.

I really just saw this thread, I proly coulda saved you alot of time. those porting kits are a bunch of bull. get your self a decent set of rotary files. and if possible,get a flex adapter for your drill/ driver. especially on aluminum heads, you can remove metal very quickly. in one 4 or so hour session, I ground about 2 lbs out of the 2.8 heads, which are cast iron, opened the ports up to gasket size, and cleaned the large casting flaws out of the bowls. all now matched ported and lightly polished on the exhaust.
sand paper and stones are finishing tools. for bulk metal removal, they just don;t cut it.
for anyone going to start this, use the right tools for the material.works faster with less fatigue.

here is a typical set if you don;t know what they are. local tool suppliers usually have them at assorted prices.
http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_39812_39812

quote Originally posted by tjm4fun: well, I must say you took the negative comments well. good for you. you WILL see a gain from this. cleaning up the heads on any motor will help the flow. each motor and head set has it;s own quirks, bad spots, and with some the best you can do is make them less miserable.

This is where having experience with the 3.4 DOHC helps. While I won't say that porting won't help, in fact my heads are getting a professional redesign/port right now, you may be exagerrating it a bit. Our heads are already the 3rd highest flowing heads ever put on a factory GM vehicle, performing better than the Northstar heads, Quad 4 HO head, Ecotec, 3.5 DOHC, etc. The only heads to flow more are the LT5 ZR1 Corvette heads, and the new LS7 Z06 Corvette heads, which are CNC ported btw. Our's flow bwteen 270-280cfm intake stock, and that alone is astonishing. So for a stock or relatively stock engine, I don't think that making the ports bigger will help in the least. Most of the gains will be in fuel atomization, especially with the short distance you have to distribute the fuel to two different valve entries. Aside from this, gains can, and will be had from the exhaust side. The exhaust side is where our heads suffer the most, and making them bigger and increasing flow is bound to help, assuming you can get the air in, which is a problem with the stock cams, cam timing, and intake manifold.

Yes, cleaning the heads on any motor will help flow. That doesn't mean it will help power. Northstars make more HP/cyl and HP/l than we do with heads that outflow their's significantly.

I do think you will see gains from this, but to be perfectly honest, I think the time and money would be much better spent on a better intake manifold and cams. Now all 3 of these together, with a tuned set of equal length headers, and you have the recipe for surpassing 120hp/l normally aspirated, which would be amazing.

I hope no one took my above comments as negative, I was just sayin, Id love to see a flow chart to see what happens, and throwing out there the idea of problems with uneven flow. Ive been watching this thread from day one, though not as much lately but im very interested to see how this turns out.

I think you misunderstood. I wasn't picking on anyone's comments about the worthiness of doing this. everyone has opinions about porting/polishing etc. Nor was I commenting about the relative flow on these heads. it was meant to be a general comment on the worthiness of porting on heads in general, cause some heads really aren't that good , and do respond very nicely to porting.
Also, these are mass produced heads, and I've seen many heads that had extra material (lumps) left in a port reducing its cross sectional area by almost 1/3! this compared to other ports on the same head! All heads should be checked for this before assembly.
this is something that should be checked and corrected on any head before re-assembly. Porting is not going to hurt anything, unless of course if you cut into a water jacket. IF you at least gasket match, remove irregularities, you will help the flow, and any future bolt-ons like intakes and exhaust pieces will also perform better.
I really wanted to point out that the job is way easier using the correct tools. to remove quantity of metal, you use a cutting type tool, a rotary file. to smooth and finish you use grinding tools, like a stone or sandpaper. this is especially true in cast iron heads, where it will eat those sanding wheels and small stones right up.

Where can you get performance parts (valvetrain, low end, headers) for the TDC?

Or dont they make them?