Breaking in a fresh rebuild with ITBs and MS3

[Laminar]

I've started building up the engine for my Cougar - it will be a 351W-based 393 stroker, 10.6ish compression, forged pistons with moly rings (Wiseco 5013h3), aluminum heads, and a pair of Hayabusa ITB racks feeding a Weber 8-stack manifold. I plan on running an MS3X with a 36-1 crank wheel, an Explorer 5.0/Mustang 3.8 combined cam sensor for sequential injection and ignition with LS coils.

Needless to say, I don't have a good base tune to start with here like I did for the 5.0 in the M3.

I've read lots and believe I have a good understanding of how to dial in ITB mode once the engine is running and the car is road-worthy, but I'm just worried about the initial startup and the potential to be a bit hard on the engine until I get the initial settings dialed in closer to where they need to be.

As the initial startup is critical to breaking in the engine properly and ensuring longevity, what precautions can I take regarding cranking settings and initial values for the tune? I assume I'll want to err on the lean side for cranking pulsewidth so that I don't wash the cylinder walls trying to get it fired up.

I'm considering making a little injector test bench so I know that my flow ratings and deadtimes are spot on, I think that would be useful in this situation. Anything else I could do to prepare?

[EspeNS]

I think I would start the engine and do the break in with pure Alpha N, to keep things simple. ITB mode has to many settings that have to match that I would not risk to ruin the breake in with wrong settings.

[Yves]

If you start tuning at the lower rpm band/cruise areas, the itb load will mostly be based on map and less so on TP. The itb curves at that point are not so important. When stabbing the throttle with enough authority for ego and ae, you shouldn't run into issues when not staying on the throttle too long and will let you establish the parameters needed to set the curves imo. The rest is pretty straight forward.

Once idle is dialed in, you set the VE and ignition curves to something that seems reasonable. Let VEAL deal with it from there to get you close.

[DLRacing]

I've started building up the engine for my Cougar - it will be a 351W-based 393 stroker, 10.6ish compression, forged pistons with moly rings (Wiseco 5013h3), aluminum heads, and a pair of Hayabusa ITB racks feeding a Weber 8-stack manifold. I plan on running an MS3X with a 36-1 crank wheel, an Explorer 5.0/Mustang 3.8 combined cam sensor for sequential injection and ignition with LS coils.

Needless to say, I don't have a good base tune to start with here like I did for the 5.0 in the M3.

I've read lots and believe I have a good understanding of how to dial in ITB mode once the engine is running and the car is road-worthy, but I'm just worried about the initial startup and the potential to be a bit hard on the engine until I get the initial settings dialed in closer to where they need to be.

As the initial startup is critical to breaking in the engine properly and ensuring longevity, what precautions can I take regarding cranking settings and initial values for the tune? I assume I'll want to err on the lean side for cranking pulsewidth so that I don't wash the cylinder walls trying to get it fired up.

I'm considering making a little injector test bench so I know that my flow ratings and deadtimes are spot on, I think that would be useful in this situation. Anything else I could do to prepare?

Sorry, this doesn't really address your question, but are 46mm motorcycle throttle bodies going to be large enough for a 6.4 liter engine?
I ask because I'm in the process of building my 2.3 Liter Duratec, and will probably be going with 50mm throttle bodies on it.
I'd think you'd want at least 58mm or so for max power on that V8.

[Laminar]

Sorry, this doesn't really address your question, but are 46mm motorcycle throttle bodies going to be large enough for a 6.4 liter engine?
I ask because I'm in the process of building my 2.3 Liter Duratec, and will probably be going with 50mm throttle bodies on it.
I'd think you'd want at least 58mm or so for max power on that V8.

That’s a valid point. They are a bit small based on max flow power numbers. But my heads are, too. The connection to the intake manifold will be smooth and well-ported, and I’ll make some velocity stacks to maximize flow. Borla has quite a few sets of ITBs and most designed for over 500hp are in the 50-55mm range. But that’s $5000 vs the $500 I have in it.

http://racehead.com.au/designing-perfor ... uld-i-use/

My heads flow 300cfm, 120%-140% of that is 360cfm-420cfm. Based on that site’s design data, my setup can work well. If I was running more radical heads this combo would be capable of well north of 600hp and then I’d start to worry about ITB diameter.