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| Head Porting how much is to much??? https://slantsix.org/forum/viewtopic.php?t=43484 |
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| Author: | 75customdart [ Tue Feb 01, 2011 12:32 pm ] |
| Post subject: | Head Porting how much is to much??? |
Started working on another head today at work and got to thinking how much is to much? When do you call it quits? How big is to big? I have 5 hours in one intake port and it needs another 45 min till it's "done". Does anyone have pictures of there porting work there willing to share? I'll snap some pictures of mine tomorrow after I get an exhaust finished. Please share any ideas. |
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| Author: | Dart270 [ Tue Feb 01, 2011 3:02 pm ] |
| Post subject: | |
When you put a hole into the water jacket, that's too much.  I've done that...DO NOT try to totally blend/smooth the area between the int/exh ports where there's a little bump. That's where I hit water. Tilley even warned me about it beforehand... Sorry, no pics from me. Lou |
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| Author: | Rick Covalt [ Tue Feb 01, 2011 3:10 pm ] |
| Post subject: | Time wise? |
Cory, Not sure this helps but when I did Ryan's head I think I had about 16-20 hours total in the head. Mainly the area under the valve and around the valve guide. I did not enlarge the runners all that much. We are pleased with how it runs. It sounds like you are spending quite a bit more time on yours. Rick |
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| Author: | 75customdart [ Tue Feb 01, 2011 4:08 pm ] |
| Post subject: | |
Thanks for the tips guys! I'm hoping to get more done tomorrow, I think I'm just being to picky. But I figure the more time spent the better. Any special tools you guys use or found to work better than others? |
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| Author: | 1974duster kev [ Tue Feb 01, 2011 4:24 pm ] |
| Post subject: | |
I probably put 50-60 hours in my head i was mainly using stones so my hours may be more because of that but i did take some measurements with a caliper of the outside of the runners and i tryed to keep them evenly opened up all the way to the valve. Head started i dont have my notes infront of me but height was 1.15 inches width of port was like .90 inch on the exhaust, after i was done it was 1.3inch tall 1.10 inch wide I think the intakes were something like 1.20 tall by 1.10 wide, after work 1.35 tall by 1.25 wide. When i was doing the runners i took more material from the bottom trying to straighten the path of the air so it didnt have as sharp of a bend on its way in and out. Then i oversized the valves and blended alot in the bowl area so the air should have a nice swoop in and out.Also polished the exhaust ports to glass smooth and the combustion chambers. I have no flow numbers to prove anything but i took a very slow and calculating approach to the porting and did lots of research so i think it turned out fantastic. Kev |
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| Author: | Doc [ Tue Feb 01, 2011 4:37 pm ] |
| Post subject: | |
http://www.slantsix.org/forum/viewtopic.php?t=41693 http://www.slantsix.org/forum/viewtopic.php?t=25303 |
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| Author: | Exner Geek [ Tue Feb 01, 2011 6:23 pm ] |
| Post subject: | |
I don't do my own porting but I have had heads ported by several professionals. Where you take the material from is more important than how much, the flow bench is the best indication of what works. Like Lou says, take it easy on the areas under the valve where the ports are the closest together, especially in the exhaust port. Avoid using Serdi type cutters that pilot in the valve guide on the exhaust. Better to grind by hand and bias the exhaust bowl away from the intake side. Two of my heads have holed through just where we are taking about. Core shift probably plays a role, Cameron Tilley used a sonic tester when he created his most successful ports. Good Luck. |
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| Author: | madmax/6 [ Tue Feb 01, 2011 7:35 pm ] |
| Post subject: | |
Mike Jeffries barely touches the sides,and his heads are proven.He told me that the heads that he has tested with wide ports flow less than ones that are left alone.He works the tops and bottoms.Mark |
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| Author: | DusterIdiot [ Tue Feb 01, 2011 8:44 pm ] |
| Post subject: | Yep... |
Quote: He works the tops and bottoms.
I port match the sides and remove as little as possible, do little work on the "throat" or floor of the port as the mix can't "bend" on that short of a notice...best velocity is at the back of the port/roof...I'd be interested in seeing a see through model of the head and cylinder to see if the mix actually falls down the back of the port and causes more tumble in the bore when it's filling the cylinder if this area is worked more...-D.Idiot |
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| Author: | 60 Plymouth [ Wed Feb 02, 2011 2:23 am ] |
| Post subject: | |
I have no practical experience porting with a grinder, but have played about with a flow bench a few times. In my opinion, one of the best sources of information on porting is diyporting.com. The guy who does it is a Ford enthusiast, so the numbers don't directly apply but the theory and technique do. He also has some evidence to show that you can remove too much material from a port: http://www.diyporting.com/E7p3.html This page gives some numbers taken on the flow bench at different stages of porting. IMO this guy has really done it properly, he's performed a different test after each and every modification to see what the effect is. This si the sort of thing that I wouldn't mind doing at some point for all the Slant 6 enthusiasts, but over here in the UK I can't just pick up scrap heads for next to nothing. Anyway, there's a few useful hints and tips on this site that might be able to help you make the most out of your time. Even if it's no help, it's a good read! |
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| Author: | 75customdart [ Wed Feb 02, 2011 8:27 am ] |
| Post subject: | |
Doc is completely removing the ski ramp to the valve guide a bad idea? I've be trying remove as much from the top as I can trying to make it almost level. Thoughts? |
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| Author: | Dart270 [ Wed Feb 02, 2011 9:06 am ] |
| Post subject: | |
Tilley's heads had the exh guide boss (ramps) totally flattened, and int he just had a little bit of it left, tapered into the valve stem. Lou |
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| Author: | Doc [ Wed Feb 02, 2011 10:20 am ] |
| Post subject: | |
Higher flow heads remove some of the guide boss as discribed by Lou. For "street performance" I tend to leave more guide so there is better valve stem support and more surface area to reduce long term wear. You can thin-out the bosses a lot, with-out removing a bunch of guide length. DD |
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| Author: | 75customdart [ Fri Feb 04, 2011 12:17 pm ] |
| Post subject: | |
Wonderful thanks guys! Few more hours of work and it's heading to the flowbench! |
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| Author: | 1974duster kev [ Fri Feb 04, 2011 4:57 pm ] |
| Post subject: | |
sweet! i'm interested to see what it flows. Kev |
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