Porting stock ls1 heads?
02-13-2005, 05:12 PM
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Porting stock ls1 heads? Has anyone ported there stock heads(ls1) ??? if so, what were the flow numbers and any dyno/track results. I'm in the process of getting a set done
3 weeks now and its the only bench racing I can do till the track opens in March. Any comments appreciated.
3 weeks now and its the only bench racing I can do till the track opens in March. Any comments appreciated.
02-15-2005, 01:24 PM
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I"m in the middle of doing it. If you check my cardomain website I have pictures of the stock ports and I'll have pics of the ported ones up soon. I won't have flow numbers, but I'll have dyno numbers in april when my club does it's dyno day!
02-15-2005, 01:49 PM
#4
If you plan to install s/s valves, upgraded springs, tit retainers, and other new parts with a 5 angle valve job total up the costs.... you will only spend a few hundred more on professionally CNC ported heads that flow 300cfm with all those upgrades already. You get even flow between ports, same size cc in the chambers... Heads are a very important part of the equation.
I looked at porting some 5.3 heads I picked up and after totalling it up, then adding in the 20-30 hours of my porting/blending labor... it wasn't worth it for results that would be lack luster. Most home head porters get in the 275cfm range or less.... almost all vendors state they can get 300cfm. Too large a port runner volume will kill flow down low.
LS1 heads are tricky to port and over the years they have evolved into what they are now. I wouldn't expect kick *ss results from this being your first set of LS1 head work. 2 years ago they weren't getting much over 400rwhp with cam/heads. Now they easily surpass that by 30-50rwhp.
Good luck,
-Mark
I looked at porting some 5.3 heads I picked up and after totalling it up, then adding in the 20-30 hours of my porting/blending labor... it wasn't worth it for results that would be lack luster. Most home head porters get in the 275cfm range or less.... almost all vendors state they can get 300cfm. Too large a port runner volume will kill flow down low.
LS1 heads are tricky to port and over the years they have evolved into what they are now. I wouldn't expect kick *ss results from this being your first set of LS1 head work. 2 years ago they weren't getting much over 400rwhp with cam/heads. Now they easily surpass that by 30-50rwhp.
Good luck,
-Mark
Last edited by gnx7; 02-15-2005 at 03:12 PM.
02-15-2005, 02:41 PM
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I just ported mine. I haven't flowed them so I don't have numbers, but the car runs very well with them. I didn't really touch the chambers; just bead blasted them to clean out the carbon. Took about half the swirl ramp out, and all of the rocker bolt bulge. Took out some around the valve guides. I didn't really hog them out, just a general smoothing and blending. Polished the exhaust ports but left the intakes textured.
02-15-2005, 03:08 PM
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I have flowed two sets of mine and the usually go around 272/205 @ .600, flowing another one here in the next week or so. They are production valved heads that cc out aound 215/80.
02-15-2005, 04:03 PM
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Originally Posted by Bo White
I have flowed two sets of mine and the usually go around 272/205 @ .600, flowing another one here in the next week or so. They are production valved heads that cc out aound 215/80.
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02-16-2005, 12:05 PM
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Originally Posted by Bo White
No pipe.
02-16-2005, 12:09 PM
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Will not be long on both for mine. Some people have already got some differences posted up in the past that they or a buddy ported their heads and reran/redynoed but do not remember any specific #s.
02-16-2005, 03:22 PM
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I have ported A few sets of Ls1 heads I dont have any pics on this cpu..I do the cylinder head porting for h.c.i motorsports which is all late model mustangs but have gone into ls1/ls6 recently I reccomend reading a few books like how to build & modify chevrolet small block heads the concepts are pretty much the same. you can find it at borders book stores..I get all my porting material from www.Ruffstuff.com they are located in sacramento C.A. Good luck and stay off the floors
Dave
Dave
02-16-2005, 04:16 PM
#13
That looks like an excellent supplier! I wish I had known about them sooner.
It's nice to have a couple of differnt sized die grinders, maybe a small one plus a really small one. Some carbide burrs, some sanding rolls, and some of those great little flap wheels. Be sure to use thin oil like WD40 with the burrs so they don't load up with aluminum. And be glad LS1 heads are aluminum rather than iron; much easier to cut.
It's nice to have a couple of differnt sized die grinders, maybe a small one plus a really small one. Some carbide burrs, some sanding rolls, and some of those great little flap wheels. Be sure to use thin oil like WD40 with the burrs so they don't load up with aluminum. And be glad LS1 heads are aluminum rather than iron; much easier to cut.
02-19-2005, 08:42 PM
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Well just got done doing mine. Man my neck is sore from looking down that little hole! LOL! Anyway, here are some before and after pics!
exhaust:
before, after
Intake:
exhaust:
before, after
Intake:
02-20-2005, 12:04 PM
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Originally Posted by Bo White
Good, now get some sand paper rolls and blend it all in and you should be good. 
If so please post!!!
02-20-2005, 01:06 PM
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I don't have anywhere to flow them and they need to be back on the car in a day or two so I don't have time to flow them. However, I'll post up the HP gains when I dyno it!
02-21-2005, 12:37 AM
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Garage Porting can be very effective if you know what you are doing. I started out a few years ago around 19 or I made all the typical mistake that a virgin head porter could lowering the port floor port matching to the gaskets all kind of silly things since then i have read several boring books and my skills have improved by far here are some really old ls1 heads i did a while back these where my first set that I did.. Plus a set of 4v heads that are going on a stock short block 98 cobra that should have no trouble running ten 4v flow around 310-330 on the intake at .500 and 210-230 on the exhaust...[IMG]
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