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| V6 iron cylinder head (Page 1/12) |
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lordfiero
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NOV 25, 10:34 AM
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New member, new thread 
Lets talk about the fiero heads..
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lordfiero
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NOV 25, 10:57 AM
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I did have plans to port the heads while the engine is in pieces..
The intake ports are typical GM 80s design, in this case steering the flow upwards and sideways via the blob in the middle of the passage, somewhat like the swirl ports on the 350 smallblocks(TBI version) althoug the intention of that one was creating a vortec.
the exhaust port definetly looks worse than the intake, the runner is not straight (at all) and there is a hump blocking the flow. This is probably a consequence of the spark plug location interfering with the exhaust port. Hmm
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lordfiero
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NOV 25, 11:17 AM
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And this is what happens when trying to machine the hump to flatness.. and shape the port to a modern D-shape.
The extruding part of the hump is the wall, there is no additional metal behind it.. Everything looked ok until the last pass in the mill but Im glad I found out, otherwise I would have walls as thin as a hair out to the coolant. That would have been a catastrophe waiting to happen.. 
So heads up for that one if you plan to port these heads.
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Blacktree
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NOV 25, 02:00 PM
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What you did with the exhaust port looks similar to how I ported mine. My main goal was to create a flat floor in the exhaust port, from the valve bowl out to the header. And as you mentioned, one has to be careful not to cut into a water passage, or the spark plug recess.
On the intake, don't remove that fin in the center. This seems counter-intuitive, but that fin increases flow by about 15%. That said, it might be a good idea to sharpen the leading edge, to reduce aero drag. There are some gains to be made from smoothing out the valve guide area. There are big hunks of metal sticking out into the airflow path. Plus the transition from valve bowl to runner is pretty ugly.[This message has been edited by Blacktree (edited 11-25-2018).]
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lou_dias
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NOV 26, 02:48 PM
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I ported mine 1.25" if you wanted to D port them, you may have to twist where you bore to avoid such issues. The AL heads have twisted bores as well.
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Blacktree
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NOV 26, 04:12 PM
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| quote | | Originally posted by lou_dias: ...if you wanted to D port them, you may have to twist where you bore to avoid such issues. |
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Yeah, I had to do that.
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lordfiero
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NOV 26, 04:58 PM
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Great to see some pictures of other porting jobs and hear your experinece of this!
Yes the runner tilts approx 7 degrees sideways so cutting at that angle would probably been better but then I have to watch the opposite wall instead :/ I may try somewhere between...
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lordfiero
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NOV 26, 05:02 PM
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Lets have a closer look inside the head
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lordfiero
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NOV 27, 05:34 PM
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Fiero head surgery
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lou_dias
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NOV 28, 09:21 AM
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I assume for educational purposes...
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