Once you verify timing, leaks, etc it needs to run at the break-in RPM ASAP. The break-in procedure calls for the high RPM to ensure adequate oiling. My last engine builder didn't want me to idle at all...in fact he doesn't like an engine to idle ever! He claims that is where the majority of wear occurs.

With cast iron heads and block I might be tempted to re-torque but it's a gamble in this case, especially with the time and money you have invested so far. I'm not sure what I would do. Your plugs look fine btw...nothing dramatic.

Any water in the crankcase oil?

 

The other thing I was going to add was that after my initial start-up I too had the engine die a couple times and it was always after giving her some revs. I was trying to make sure everything was good and to get the water temp up so I held it at 2000 for a bit (sounds really good too without any exhaust).

After letting off it stumbled badly and wanted to die. I could keep it going a bit with throttle but then it died. I attributed it to the fact that I wasn't running any exhaust (no O2's). Of course I didn't have the smoke but wanted to share that with you.

You didn't dump a bunch of Seafoam in and forget about it did you?

 

I added a bottle of redline engine break in oil additive and the oil pump was primed with engine assembly lube.

Mine hesitated a bit getting up to 2500.

It's strange how it ran absolutely beautiful for a good 20 seconds before the white cloud started. I know other people have used less than 80 ft-lb on ARP head studs without problems too. Maybe I somehow plugged a coolant line into a vacuum line

I tried starting it once more after it died. It started, hesitated a lot, smoked, and died all within 10 seconds.

 

I knew a guy who rebuilt diesel engines, and I mean truck and bulldozer engines, he would start them, let them build oil pressure and then run it right to the governor and hold it there for 10 min.
He said if it was going to blow up it would do it then, they never did.

 

While looking for idiot mistakes, I did just notice the coolant temperature sensor was unplugged.

 

Only small coolant lines are the two going to/from the throttle plate heater. Have heard of it leaking, but not injecting water into system, buy=t who knows? You can do a plumbing bypass, it is a safety issue for intake icing, do this for testing only!

 

1. There is no idiot in your garage. You have earned the respect and admiration of forum members, and inspired others to undertake difficult projects.

2. Coolant sensor unpluged (non-gauge) will tell ECM it is -40F, and ECM wil run at richer mixture, might idle high. No big deal.

3. Coolant sensor - gauge (one wire) - unplugged only impacts gauge on D1. D2 uses one sensor to drive ECM, then ECM drives gauge.

 

After finding another connector unplugged (honestly don't know what it is) I tried again but it made no difference.

It ran perfect for 10 seconds, I revved it up to 2500, and as the engine warmed up it smoked more and more until it died. A tiny amount of smoke also seemed to be coming from the left exhaust manifold area. You'll also see that plug 4 looks a bit darker, and looking down the plug hole it seems to be a bit more "wet" than the others. It's really hard to see though.

 

Any water in the oil or vice-versa?

The coolant lines that run under the throttle plate are about the same size as the one that goes into the Ram's Horn. Until I hooked the PCV system back up I was trying to figure that out. It would be really difficult to do but I suppose you could have run one side from the throttle plate heater into the air-intake by mistake thereby dumping a bunch of water into the intake once the t-stat opened.

Like I said, very unlikely but possible. Our engines aren't identical so I don't know the plumbing layout on yours as well as mine.

 

So it smoked white smoke! Like Matt asked, any sign of moisture? I don't believe it's coolant but what you packed the oil pump with. What ARP kit# do you have? I'll check it out, report back.

(OT) Matt, our engines are identical except for the cross bolt mains and some additional webbing. The heads are the exact same, even the displacement is the exact same but to make the newer blocks more exciting they labeled them 4.0. You have a dizzy and a way easier FI system to play with. They eliminated a few head bolts and use only 10 on the GEMs. You could have left the extra's out and some Landy mech's do. The engineers found it makes no difference in clamping force or torsion. That's not to say all of your system is plug and play since the 96-mid99 was OBDII and had the system upgraded in stages to match the mandates. Even the front cover on a GEMS has the location for the dizzy and hold down cast but not bored, they're blanked..... Also, ARP's are designed to be reused otherwise they'd use bolts in racing. Head bolts are TTY which is why they are indexed and tossed. Studs are torqued in three steps and yes, 80lbs sounds about right since a 2004+ GenIII 350's are 75lbs with the M11's.