Question for those who have ported your LS3/L92 heads???
#41
I highly doubt that'll happen but you never know. Once I get everything going I'll call a few shops and see what they say. There's a local speed shop that sells CNC ported LS3 heads. I can see if they'd be willing to get in on the action in exchange for some exposure.
#42
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The other problem with comparing stock heads to "ported"...ported by who? You can port the heads and make it WORSE than it was...you can port them and make it better. People who know how they're porting can port them some...or more...and their "stage 1" and "stage 2" are probably different than someone else's similarly named heads...and some of what they've done is more intended for a 4.06 bore than an LS3 already has, while others are going to be doing work to the chambers that might be intended to work better with a bigger bore...
The work involved in comparing GM's castings, to brand X's ports, brand Y's ports, brand Z's ports, and every other "head porter" under the sun is just nuts...you have to look at their TRACK records on previous customers, previous GM heads of similar design, commitment to stand behind their work, history of not screwing their customers over and so many more other factors.
I'm not trying to insult you, I'm just saying, it's a much much much more complicated comparison than you think it is...and any vendor who sells some of the products in the test for more profit than other products in the test...or doesn't even sell some of them...is going to skew the results...any porter involved in the test is going to try to skew them too...the only way to make it a fair honest test...is some "random person" that none of the vendors and porters even know, needs to be the person ordering the countless sets of heads...then they need to evaluate them on an ENGINE dyno, in a dyno cell, with controlled environment...not on a chassis dyno using poor "correction factors" to try to correct for an uncontrolled environment.
#43
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If Danny goes through with the testing he should test stock head, then ported by whoever on a stage 1 port, then test again after milling to desired thickness. Even with correction factors I would think we would be seeing the information were after. It will also show if the power is in the port work or if it's in the milling alone. For a smaller bore motor I would think that any vendors stage 1 port work would suffice where stage 2 is for 400+ ci motors.
#44
You only know from flow tests. Even average clean/valve jobs without extensive porting on LS3 heads have been generally shown to pick up about 20cfm. Excellent port jobs will pick up way more, look at WCCH website he has all his flow numbers listed at various lifts and comparisons with factory, TSP does too. Whether the rest of your combo is built to take advantage of that extra flow or not is where you have the variability.
#45
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You only know from flow tests. Even average clean/valve jobs without extensive porting on LS3 heads have been generally shown to pick up about 20cfm. Excellent port jobs will pick up way more, look at WCCH website he has all his flow numbers listed at various lifts and comparisons with factory, TSP does too. Whether the rest of your combo is built to take advantage of that extra flow or not is where you have the variability.