STAR,

Explaining the MC engine theory is beyond the scope of this bulletin board. I'd suggest a web search. I found this link on "How Stuff Works" which might explain the subject in laymen terminology.

http://www.howstuffworks.com/question132.htm

Take care

 

I'd go gen 1 sbc due to the wider range of people that have activly supported it over the years in the aftermarket. That said I'd be purchasing a World Motown 427 on the 650hp platform with all the goodies to support boost..
..and lots of it.
oh I'd get the EFI option intake of course so Not to have to play around with it.
Add a F.A.S.T. wideband system with 160 pound a hour squiters and visit Harry for a single 90mm or larger turbo, pluming, race gate, intercooler, and a hat.
...the hat's not for your head

 

Couldn't agree more about the $$$. But better than gen I (if a big block is out)? What are you thinking of?

Rich

 

I think I see where you are going with it, and I'd recommend the Gen I stuff for a couple of reasons. First, it will probably be easier/cheaper to get a custom cam for your intentions with GEN I. You also simplify the install a ton, since you can use a distributor, and a carb. Yes, they have a carb'd intake for the Gen III now, but I haven't seen any results yet. Also, you greatly magnify the clylinder head choice with a GEN I. With Gen III, all you can choose from is stock, ported stock, or AFR, which also hasn't been used to death yet. I'd also recommend a turbo instead of a centrifugal. You'll have more power at lower rpms, plus you don't have to worry about a belt/bracket for it.

After reading a bit on the Miller Cycle, which I'll admit I had never heard of, it appears you do need a supercharger, and possibly a positive displacement blower at that. In that case, I'd definitely go Gen I, as the Magnacharger is the only positive displacement I've seen for the Gen III. Curious though, would you not run into some piston/valve clearance issues with an extra 30 degrees of the intake valve being open? And, from what I've read, my understanding is that it is only open longer on the compression stroke. Wouldn't that entail some sort of variable valve timing?

 

Yeah, I'd been leaning towards the Gen I stuff from the beginning, specifically a Motown block and heads. (Little Chiefs)

I just wanted to make sure that i wasn't missing the boat by not going with Gen III.

As to the piston/valve clearance, it's not a problem. The valve just hangs open a bit past BDC, so the valve would be closed long before the piston got near it.

As to the variable timing, it's not needed because on the exhaust stroke, although the intake valve is hanging open past BDC, there is air flowing past the intake valve with greater pressure than what exists in the exhaust port, so you don't get backflow. In fact, you get a nice cooling effect.

On a carb'd engine, I would be very concerned about the large quantities of hydrocarbons being blown out the exhaust, but with fuel injection the injector wont spray on that stroke.

And yes, I do plan to run fuel injection.

I do still want to use a centirfugal supercharger, specifically because of it's boost characteristics, but this is where what I've learned about the Miller cycle begins to break down. I simply don't know how much boost I need at lower RPMs for a Miller cycle to work. Nor do I know what the appropriate cam specs would be.

If push comes to shove, I plan to dump the Miller idea and stick with the core of my original idea, which is essentially to, for lack of a better way of expressing the notion, end up with a gas pedal that reacts like a rheostat.

I know... that's a silly notion. I'm just going for a decent analogy here that conveys the idea in a way that you can relate to, even though it's not REALLY an accurate representation of what I plan to do.