Everyone i talked to said shortside radius shirtside radius shortside radius on the intake and exhuast so thats where i concentrated about 75% of my effort :-) and this came from about 3 people who get about 270 cfm or so once ported

I know the valve guide bosses could have been cut down some but being a first timer i didnt want to go to crazy so i cleaned up the bowls as best i could and evened out the throat cut from the valve job abnd worked the shortsides over :-)
http://www.gettintheshaft.com/kc104/tta/

As far as tools and time go i did my damndest with what i had available and free time allowed
SO check it out


please check them out and give me your opinions (good ones i hope) also for first timers i can give u a few pointers and/or info on tools/nits u should use pick up for the job etc
email if u like
thanks and later

 

Look'n good!

 

I've seen better.

 

3.8,

Those look like the bowls have been opened nicely, and as you stated you could have trimmed the flat bottoms of the valve guide bosses a bit more, especially on the sides facing the ports. The little bit of intrusion left shouldn't be a major problem for street heads.

It's a little difficult to tell from the photos, and the first photo is the only one I saw that shows the valve bowls from the port flange side. It looks like the radius has been cut down enough, but the angle of the photo is a little low.

Could you get some photos of the intakes from the port flange/runner side?

Keep it up - they should be getting better flow already. Do you have a burette or graduated clyinder to check port volumes when finished, just out of curiosity?

 

You are definately on the right track I would just make shure the ports are as simular as I could and call it a day. The vortec heads flow more then the fast burns on the intake but flow much less on the exhaust side. A friend and I were going to get some vortecs fro his 350 and do exactly what you are doing but focus more on the exhaust side and polish the intake but he decided to use his sportsman II heads.

 

3.8,

Since Poncho brought up the situation with the exhaust ports, I thought I'd expound.

The Vortec head castings are loosely based on the LT1 heads, with the exception of the cooling passage differences and a couple of minor details. Just for grins, I grabbed a couple of your photos and compared them to ported LT1 heads. After scaling the photos to the same size, I superimposed an image of the exhaust port from each head onto the photo of the other to correct for perspective. Surely enough, the Vortec exhaust ports need some real work.

If the core shift is not excessive, you should be able to emulate the LT1 exhaust ports, which, as shown in the photo, has a lot less obstruction on the short side and a slightly taller port. The "D" shape of the LT1 port means there is more open area at the lower (valve) side of the port and runner, probably explaining the improved exhaust flow.

Check your castings by inspecting through the cooling passage openings, but I'm guessing you should be able to do the same thing on your Vortecs to get them to flow more like LT1/4 heads on the exhaust side.

 

Well thanks for the mostly kind words folks :-)

if im allowed to say it i think i even kinda impressed myself for being a first time head porter :-) lol

but what u see is what shes gonna get :-( i reassembled the heads about 30 min after those photos were taken and the car is going under the knife this wends :-) yeehaaaaaaaah

but i do have access to a another set of vortecs for free :-) so i may start working those over or even cut thru them to see how far i could truly go with them........since if things follow thru with the swap and i have $$$$ left after i rebuild the engine in the TTA i will be assemmbling a forged stroker or a 355 for the formie to complement the rest of the goodies on it and to run some type of boost eventually :-)

as far as the exhuast side goes i went inot the shorturrn radius as much as i dared not having a cut opne head to look at :-( everyone warned me about not going to deep on the shortsides becuase u dont have terrible amount of room to go or your gonna hit the water jacket , but i did grind down the casting lines etc and polish the exhuast side as good as possible and cut down the shortside of course nd blended it nicely as possible
so what u have seen i s what shes going to get :-)

damn she gonna be a rocket lol
later and thanks
jeremy/tta/3.8TransAM

 

zoom zoom

 

3.8,

They must at least flow better than they did. Better safe than sorry. Maybe you can get wicked on the next pair.

And where are you finding all these "free" Vortec heads, anyway? If you can get enought of them to cut in half to experiment, I'd like to do a little experimentation myself...