DIY head porting??
Uhh No !!! Bad Idea, unless you really know what your doing. There is more to head porting than just hogging out the port or think your just gasket matching. I would recomennd a BIG negative on this idea.
Originally Posted by edlt1
has anyone tried porting their own heads??
if so let me know I amthinking about doing it for the first time.
Ed
if so let me know I amthinking about doing it for the first time.
Ed
I get a lot of work from people who try and port there own heads. You'll do more harm then good, there will be some guys on this forun that say otherwise, but I have seen many heads to far gone to fix.
I tried on a set of LT1 heads.
Did 3 cylinders and left one stock (just one head). Took them to get flowed. Stock was something like 205 cfm on the intake... my "ported" intakes flowed from 215 to 230. OK, called for more porting.
So I ported all 8. New valves, valve job, the whole bit. Took them and got all 8 cylinders flowed. Lowest cylinder intake flow was 195, highest was 230. Port volume was huge. At this point I said screw it, cut my losses, and bought a set of professionally ported heads.
After talking with the flow bench guy, I did learn what to look for in a bad port job.
But I didn't want to pay him any more money for flowbench time (it ain't free, ya know). I chalk it up to a learning experience. I spent about $400 for that 'lesson' in head porting.
If you have free access to a flowbench, I'd definitely go for it. Without one, you're shooting in the dark (as I was).
Did 3 cylinders and left one stock (just one head). Took them to get flowed. Stock was something like 205 cfm on the intake... my "ported" intakes flowed from 215 to 230. OK, called for more porting.
So I ported all 8. New valves, valve job, the whole bit. Took them and got all 8 cylinders flowed. Lowest cylinder intake flow was 195, highest was 230. Port volume was huge. At this point I said screw it, cut my losses, and bought a set of professionally ported heads.

After talking with the flow bench guy, I did learn what to look for in a bad port job.
But I didn't want to pay him any more money for flowbench time (it ain't free, ya know). I chalk it up to a learning experience. I spent about $400 for that 'lesson' in head porting.If you have free access to a flowbench, I'd definitely go for it. Without one, you're shooting in the dark (as I was).
my friend did it to my heads and the car dynoed 390/390 through a street twin and a denny d-shaft and a 9 inch so I guess it was an alright job done. Well know when i buy my trick flows and have them ported by lloyd to see how much i gain
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Originally Posted by MrBill97396
How much thinner where you planning on making the common wall ? And are you going to try and straighten it back up ? Make sure to order some AB epoxy !!
Originally Posted by MrBill97396
Uhh No !!! Bad Idea, unless you really know what your doing. There is more to head porting than just hogging out the port or think your just gasket matching. I would recomennd a BIG negative on this idea.
You dont want them to smooth, then you start messing with the fuel puddling. that is why you use a fine grit cartridge roll. If you are planning on moving any material out you will need a good supply of cartridge rolls, and dont take any off the floor of the port. You could mess up the short turna and then you may as well toss them.
Fuel puddling is not much of a problem on an EFI engine.
I ported my last 2 sets of heads - bowl blending, port bias work, guide shaping and port matching) - one was a set of GMPP Fastburn heads (more of a cleanup and port match) and the other was a set of new Edelbrock E-TEC 200 heads. They are in my Vortech-blown 383 now and running great.
I highly recommend David Vizard's book on Modifying the Chevy Smallblock Heads. Lots of pix and examples. Good through LT4 - the LSx heads are too different.
Take your time and use sanding rolls, not aggressive carbide cutters. You can ruin a head in 30 seconds with a carbide too if you don't know what you are doing. With sanding rolls you need to work at screwing up!
Jim
I ported my last 2 sets of heads - bowl blending, port bias work, guide shaping and port matching) - one was a set of GMPP Fastburn heads (more of a cleanup and port match) and the other was a set of new Edelbrock E-TEC 200 heads. They are in my Vortech-blown 383 now and running great.
I highly recommend David Vizard's book on Modifying the Chevy Smallblock Heads. Lots of pix and examples. Good through LT4 - the LSx heads are too different.
Take your time and use sanding rolls, not aggressive carbide cutters. You can ruin a head in 30 seconds with a carbide too if you don't know what you are doing. With sanding rolls you need to work at screwing up!
Jim
Yea its better to not polish the intake manifold or the intake runners on the heads, only polish the exhast port and the combustion chamber to limit carbon deposits which will hinder airflow.
I ported my first set by just reading about how to do it and asking around. I did have a flowbench to help me along though.
I went from 198 cfm stock to 237 at peak, with gains throughout midrange. That was still with stock valves, stock valve job, and untouched chambers.
I started messing with the chambers and blending and gained a little more (lost the exact numbers) but think it was about 10cfm.
With new valves, seats, and valve job, I dont see why it wouldnt be a 265cfm head.
I went from 198 cfm stock to 237 at peak, with gains throughout midrange. That was still with stock valves, stock valve job, and untouched chambers.
I started messing with the chambers and blending and gained a little more (lost the exact numbers) but think it was about 10cfm.
With new valves, seats, and valve job, I dont see why it wouldnt be a 265cfm head.

