switch to the TR224.

 

Who ported the heads? have they ever done ls heads before?

 

Local engine shop - they have done very good work for me in the past.

 

I don't see how your cam could die like the graph indicates. Something has to be up.
I freakin rev my STOCK CAM stock motor 5.3l to 6400rpms without feeling a power drop.
I also tested my shift point numorus times at the track to verify it was doin me good to rev it that high.
By stock motor i mean i have not touched the motor period it just has full bolt ons and 4.10 gears.run 13.7@99 spinning.

 

I think even if the heads were boogered up that they wouldn't kill flow enough to warrant the sharp drop in HP.

 

I'm curious of a few things there. A stock LQ4 peaks around 5000-5200 with alot flatter torque curve. Your compression gain should certainly get you more torque. I'm kinda suspect that you were getting KR*. If you got KR* when you first went W.O.T. it would have faded away and got your torque up. It could have spiked again and lost you hp on the high end. I think the stock airbox is taking away some power. I think having an advance on a cam that small with your compression and cubes made it a bit more peaky. Getting an LQ4 to peak torque and hp that low with a cam is impressive though. Of course though we should have more info this week on mine for comparison. The LQ4 in the tahoe with unported 5.3L heads and a 224 cam should be together and running today or tomorrow. Dyno numbers soon.

 

2 things are in the works for me as of now. First and foremost I am going to a different dyno tomorrow. It's an asian ricer shop that does Mitsu's mostly but I only need 2 pulls. Secondly, if the results are the same, I'm yanking the intake tube entirely so air is going directly into the TB. I'm not running a MAF and refuse to do so, so this should resolve the question of the intake tube. If the results are the same I'm going to crack into the engine and check the cam timing. I'll borrow a degree wheel from a friend and see what we have going on. If that checks out I don't know what else to say. Everything else for certain is perfect. The only item (and probably the most important one) that I didn't check while assembling the engine was the camshaft timing. I just went dot to dot. The truck also today has developed a slight miss at the lightest of throttle but as soon as I lay into it, it cleans up. I'm going to throw another set of plugs in it as well as wires too when I get home from being out of town.
Speaking from experience building another motor a few years ago we had an olds 455 that ran like a scalded dog up top but didn't have tire melting power like you would expect from a big block olds. Long story short, after disassembly, we found that Engle ground the cam 6 degrees retarded. Put a new cam in it and holy schmoly it was a completely different beast.
At any rate, check back at the end of the day tomorrow as I should hopefully have some new numbers from somewhere else.
Zippy, get that thing of yours running and on the dyno, also post up some idle clips. I'll be getting another camshaft and trying again if this doesn't pan out the way I'd expect.

 

are you just not happy with the numbers or is it because the graph showed some weird things? 350hp and 392tq sounds pretty good to me, your cam isn't very big so thats probably the big difference in hp an tq #s

 

this guy has a little bigger cam then you and put down more hp but less tq. but everything i've read 350hp to the wheels is about right for a cammed lq4. thats what i hope i have.

https://www.performancetrucks.net/fo...d.php?t=414983

 

It's bothering me that everything fizzles out after 5400 RPM's or so. A cam my size should not fizzle out that quickly. I have to know for my own piece of mind if this is how it's supposed to run or if there's problems elsewhere. Every other 6L dyno I've seen carries well on past 6K even with similar or smaller cams. If something weird is going on, it needs to be resolved. If it's how it's supposed to be, well, then the cam isn't big enough for my needs. With the way my trans and rear end is geared, I like to do my shifting around 6-6200 RPM's. I've been doing that with my current combo but if the dyno is right, I'm losing speed by shifting that high.