Remember.To smooth port the runners in Vortec heads destroys the "Vortec effect" which is there as part of their design which suspends the A/F mixture.The exhaust side on the other hand will benefit from porting.
Who sold you that line of crap? The vortec heads perform as well as they do thanks to a tall runner, better short turn, and better chamber- it doesn't have a damn thing to do with surface finish.
Patriot went out of business,so if you have a good set,you might want to baby them.I was told they where bought out and was going to reopen in acouple of months under another name,but I didn't get who bought them or what the new name was.
I am very sure by a reliable source the Vortec heads rough surface plays a role in the performance of the heads by suspending the A/F mixture.That you can benefit from porting the exhaust side,but not to alter the intake runner.That if you smooth port the intake runner,what your left with is just another set of OEM castings.
It is one of those deals that is a summary in your knowledge base you have learned along the way.
To say any port is optimized as cast is a bunch of stinky BS. Just as any other head they can be improved upon by porting the intake and exhaust, in the case of the oem production vortec heads they can be improved a great deal.
.. Obviously there is benefit in altering the intake port... that's why heads have gone from the older 157cc intake ports to 175cc and 185cc Vortec intake ports and 195cc AFR's and 235cc MoTowns, etc...
1gary. Im glad you share your knowledge with us.
I know that all members dont always agree or only partially agree,but I dont see the need for attacks.
Like you I offer my all be it limited,experiences. I enjoy learning at the same time.
I will try to be less blunt in the future,or take problems to private messages. I would like to see a few different engines and combinations in the future
+2..... I love a good debate, and any and all opinions....especially when there's experience or education behind them. Keeps things interesting....i sure as hell hope Garry isn't bowing out.....
Porting them well will take them to about 190cc's and 250-260cfm with a 1.94" valve. And if you have a 350 that is approaching 6,000 RPM (very common for most hot street builds) that can equate to some major power.
The vortec heads were a design improvement but they were also truck heads that were produced as cost effectively as possible. Which leaves a LOT of room for improvement on a hot street build.
you can, its not that tricky, just takes a little more time with a carbide bit. I've done several sets in the 190-194cc range. I keep it there as I usually use a 1.94" valve.
I finished porting the second head last night. I've got to cut the guides down, clean it, lap the valves in, clean it again and put it together. Plan on being ready to put em on and do my clearance checks, pushrod length etc... on Tuesday. Then its time to get the lil "Iron Duke" and 5-speed out and start getting everything ready for the swap. I have made my decision on the trans bolt access idea. Instead of cutting holes to get to the top bolts, thats what I did on my last S10 build, i'm gonna cut a section out of the floor pan, mig four small strips of 16ga. to the underside, lay a small bead of silicone on the strips and lay the piece I cut out right back in place after I get the motor and trans in. This way, if I ever have to pull the trans I can just pull the carpet, sound and heat dampner, floor plate up and have super easy access to the trans bolts . I've still got lots of playing to do but im gettin excited about seein what this lil flat top motor runs like.
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