Abridged version.

06' Silverado ECRB 4x4 L33 5.3L. Started with 258/277rw with air intake and exhust. Then went to 293/299rw with a cam and to 330/325rw with last round of mods. Total gain for Heads, cam, and headers was 72/48rw

Had = 293/299rw SAE
Comp LSL 215/223 .604/.615 112+5
Air intake
Summit 2 1/4" dual tip exhaust
Plugs and wires
Home ported TB
9.9:1 SCR 8.2 DCR

Mods added = 330/225rw SAE
Cal Speed 1 3/4 LT's + 3" Y-pipe
Home "ported heads" basically a clean up.
10.5 SCR 8.7 DCR

[IMG][/IMG]


Well numbers are in and frankly I thought they would be a little better considering how jacked up the heads were, the extra flow I got, and the bump in compression. But I went from 293/299rw to 330/325rw. If you factor in 20/10rw for the headers then I got 17/15rw out of the heads. I was really expecting to get 25-30 out of the heads alone. I did run out of fuel at 5,500 though and started going lean to 13.5 afr or so. The injectors were maxed at 5,000, hung in there to 115% duty cycle at 5,500 and gave up. The power basically stops climbing at 5,500 even though it pulled to 6,300. Plus I had to do about 15 freaking pulls to get both the VE and MAF tables correct. Started loosing power with the MAF hooked up no matter what I did. I was down 5/5 with the same AFR and timing. Had to add 2* through out to get the numbers back up to with in one or two of the SD tune. Got to check some things but I think I could have gone 335-340rw for sure with the fuel and a cool trans and motor. The other wierd thing was the dyno correction factor. It was the same as last time but was 8* hotter and 15% more humid. Not sure how that works. Any way uncorrected numbers were 346/335rw. They are what they are. I will get a graph up when I can get it on my Photobucket.

I did a light clean up on these heads because the exhaust valves were jacked up. Polished the chambers, cleaned up the bowls, took out the rocker hump, three angle valve job, and 30* back cut on the valves. Here are the numbers.

INT........Stock 243's........My 799's.......Gain
.100............70.8.................70.8......... ...0
.200..........138.6................151.9.......... 13.3
.300..........191.7................215.3.......... 23.6
.400..........236.0................253.7.......... 17.7
.500..........265.5................277.3.......... 11.8
.600..........265.5................262.5.......... .-3

EXH
.100...........60.4...................62.6........ ...2.2
.200.........107.4.................110.6.......... .3.2
.300.........139.0.................159.6.......... 20.5
.400.........164.3.................183.2.......... 18.9
.500.........176.9.................197.5.......... 20.6
.600.........180.1.................203.8.......... 23.7

 

do you have any time slips? and what tire size are you running? the stock 265 tire? Those are extremely heavy. But looking at the "minimal" gains you got from the original cam swap, you actually picked up more power putting headers and doing some home port work to your heads then you got from your original round of mods. I would be pretty happy since the work you did was "free" with the exception of the time you put into it. Does it feel stronger?

 

No time slips. And I am still running the heavy stock tires. That is a good way to look at it. I got a little more from the heads and headers than I did from the cam swap. I am just used to seeing 80-100rw gains from my usual H/C swaps. But those are profesionally ported heads and much larger cams. I think for what I did it did alright. There was more to be had if I didn't run out of injector. I also just checked my lifter pre-load it was around .110" which probably didn't hurt me but it def didn't help. I really want to get to 350/340rw with this thing. I am thinking an U/D pulley, manifold porting, correct pushrods, and injectors will get me there.