Pics of Heads and cam Install

[Blue_01_Z28]

The girlfriend looks busy!

[KING Z28 HAWK]

Nice! Always great to have a girl willing to work on the car. What heads cam pack did you go with?

[Blue_01_Z28]

Nice! Always great to have a girl willing to work on the car. What heads cam pack did you go with?

Yeah she did good. I got he procomp heads and Erson cam .620 int/exh 108 LSA

[Rhinohuey]

haha i like the first pic. inside the engine bay

[KING Z28 HAWK]

haha i like the first pic. inside the engine bay

+ 1 that is a nice pic

[ls1camino]

Yeah she did good. I got he procomp heads and Erson cam .620 int/exh 108 LSA

108 LSA?!?!

That is a nasty chop

[Hi-Po]

Holy hell. 108?? with 620/620?

Where are you expecting this power? Is this for the strip? That is a large cam.

[Sarge]

Good man!

[Blue_01_Z28]

Holy hell. 108?? with 620/620?

Where are you expecting this power? Is this for the strip? That is a large cam.

With the 108LSA it's supposed to have massive amounts of torque at mid range. It should have quite a bit of power from 2500 and up if I get the tune right, (Which I need help on) I can manage the mechanical part just fine, it's the tuning that I'm just starting to learn.
I just wanted a mean cruising machine.

[Hi-Po]

What's the full spec's on the cam? Am I the only one here who thinks this cam is very large for a 346??? ... and is not going to make anything close to good power at ..... 2500 RPm for the street??? I am not knocking you, this just seems like a very large LSA cam, very High lift cam to be putting in a stock cube LS1. Is this a stock Cubed LS1?

What is the duration on this cam? I'm seeing Lift and LSA. Anything else?

[Blue_01_Z28]

What's the full spec's on the cam? Am I the only one here who thinks this cam is very large for a 346??? ... and is not going to make anything close to good power at ..... 2500 RPm for the street??? I am not knocking you, this just seems like a very large LSA cam, very High lift cam to be putting in a stock cube LS1. Is this a stock Cubed LS1?

What is the duration on this cam? I'm seeing Lift and LSA. Anything else?

Grind: LSHR294/365 Intake
LSHR302/365 Exhaust
F.O 1,2,7,2,6,5,4,3 108 Lobe Separation Angle
Overlap 82
Intake opens 39 Exhaust closes 43
Intake closes 75 Exhaust opens 79

Running clearance......HOT
Valve Lift .620/.620 @.050
Duration 294/302

@ .050 Tappet Rise
Overlap 22
Intake opens 9 Exhaust closes 13
Intake closes 45 Exhaust opens 49

Duration Intake: 234 Duration Exhaust: 242
Lobe Lift Intake: .365 Lobe Lift Exhaust: .365
Intake Center Line: 108 Rocker Arm Ratio: 1.70/1

Hope thats enough info for you.

[0rion]

that's a ton of overlap.....good luck tuning that.

[Frost]

OMG is that right? 294/302 duration at 0.050?? That must be advertised dur, there is no way a cam that big could be hydraulic, it's power band would be way too high.

What is the duration at .050? As far as it goes, anything tighter than 110 LSA is typically race-only territory.

With that kind of overlap, there is no way the closed loop fueling system in the PCM can work. All of that fresh air moving out of the exhaust from overlap will saturate the O2s reading a hugely false lean. The PCM will respond by adding a crapload of fuel to try and get it "not lean", but it won't be able to and the end result is that it will run WAY rich, regardless of tuning (in closed loop). It will run rich enough that if you leave it sitting idling while warm over time it could actually was the cylinders out (and constantly foul plugs).

I would not run a cam of this sort in anything but a race car seeing as there is no real way to tune it without a 5-gas analyzer for cruise areas (which race cars do not need). The wideband will read falsely lean from the overlap just like the factory narrowbands will. This setup needs Alpha-N type fueling control, but the rest of the setup doesn't seem to match. That LS6 intake will be spent by 6-6200 so it's not the best fit for that arrangement either.

I'm not trying to give you a hard time and I'm certainly not talking smack, I'm just relating experience here.

[0rion]

That bottom set is @ .50 so it's a 234/242 .620/.620 on a 108. Did you check piston to valve clearance? That's 22 degrees overlap at .50 or 82 degrees at advertised. In comparison my 228R has zero degrees overlap @ .50. That cam is going to be rough to cruise around in I bet.

[Frost]

Well, the powerband part of my post above won't be so relevant, but the rest of it here will be:

With that kind of overlap, there is no way the closed loop fueling system in the PCM can work. All of that fresh air moving out of the exhaust from overlap will saturate the O2s reading a hugely false lean. The PCM will respond by adding a crapload of fuel to try and get it "not lean", but it won't be able to and the end result is that it will run WAY rich, regardless of tuning (in closed loop). It will run rich enough that if you leave it sitting idling while warm over time it could actually was the cylinders out (and constantly foul plugs).

I would not run a cam of this sort in anything but a race car seeing as there is no real way to tune it without a 5-gas analyzer for cruise areas (which race cars do not need). The wideband will read falsely lean from the overlap just like the factory narrowbands will. This setup needs Alpha-N type fueling control, but the rest of the setup doesn't seem to match. That LS6 intake will be spent by 6-6200 so it's not the best fit for that arrangement either.

I'm not trying to give you a hard time and I'm certainly not talking smack, I'm just relating experience here.

The only real option here is open loop tuning. Because of issues with the F-body (and vette) PCMs, open loop tunes have to be adjusted periodically to maintain commanded fueling. As long as the poster knows this and knows how to correct, I guess he could get it done, but it's gonna give him fits getting it straight. I'd do the SCR/DCR calcs too to figure out what the DCR will be on a cam like that. Also, as Orion noticed, if I had to make a guess off of the top of my head (which may be wrong, but it's my feeling), I'd say you will have to do a little flycutting of valve reliefs into the pistons.

Best of luck.

[Blue_01_Z28]

Well, the powerband part of my post above won't be so relevant, but the rest of it here will be:




The only real option here is open loop tuning. Because of issues with the F-body (and vette) PCMs, open loop tunes have to be adjusted periodically to maintain commanded fueling. As long as the poster knows this and knows how to correct, I guess he could get it done, but it's gonna give him fits getting it straight. I'd do the SCR/DCR calcs too to figure out what the DCR will be on a cam like that. Also, as Orion noticed, if I had to make a guess off of the top of my head (which may be wrong, but it's my feeling), I'd say you will have to do a little flycutting of valve reliefs into the pistons.

Best of luck.

Thanks for the info, but the car is running now and I did check the clearance to the pistons no fly cutting needed, it had about 50 thou clearance which isn't a bunch but didn't bother me. I don't think stock pistons have enough material to fly cutting. The AFR wide band reads around 14 which is good and the tune isn't even close to being right yet. It seems to work fine because when I get on the throttle it gets a little rich. AFR reads from 12.88 to 13.3. It makes sense what you said about the computer reading wanting to dump more fuel to keep from going lean. It doesn't surge as much as you may think, not a pain to drive at all in town. I do agree it will be harder to tune but I wanted to make good power so i'm willing to work harder on the tune to get it. Thanks for the tuning info though i'll look into that open loop tuning.

[Frost]

Good! I am glad to hear that it got up and moving with no trouble.

Cams can be funny animals. Sometimes the giant ones end up loving to idle.

Spend your free time in the HPT forum reading up. It's hard to see the big picture at first, but it comes together over time.