Okay, so I am getting ready to start collecting parts for my engine build. I want a large cubic inch procharger motor making 11-1200hp. Help me decide on what parts will get me there. I was thinking........

Dart big m 598

Dart pro 1 345 CNC heads

M-5 pro charger

Callies dragon slayer crank

Oliver rods

Je pistons

Basically getting ready to start building the short block. The main questions I have are what bore and stroke and why? A lot of big hp motors are built from 557 and 565's. Why not go to the 598 or 632? Also what base compression ratio would be ideal, making between 12-15 pounds of boost through a procharger? This is going to be expensive and I want to do it RIGHT the first time. Okay suggestions please.

This is just my personal opinion so I'm sure someone will flame away BUT personally I would rather have a motor with a 4.500 bore and real stabil cylinder walls IF I was building a endurance blower motor and same with the stroke, once you get too much too much stroke, you get tremendous piston speed at high rpm's/cylinder side loading and those paper thin cyl walls start deforming too. I was in Lapouttre racings shop years ago and he had 3 604/632's there with a little smidgen of cylinder web dividing the bores and all of them had blown head gaskets, looked like a bad plan to me, no one will convince me other wise, I would build a 557, 4 3/8 stroke and 4.500 bore and just give it a 1lb more boost, Smitty

m5??? wow i hope you have enough hull to support 1500 hp..start looking for a # 6 drive if you dont already have one lol.try to keep the compression between 8 to 8.5..prochargers like a little more compression..

Smitty, with the piston designs, fasteners, and gaskets that are available today you can make a 4.5" stroke and a 4.600 bore seal ok and not beat up the piston or the bore too bad but, you're 100% right the 4.5 bore 4.375 stroke build is easier on parts, better for an endurance app, and will take a hell of a beating. I like the 4.560 bore 4.250 555" deal as well. The Dart blocks are plenty thick. The big cubes aren't needed at the power level the op is looking for. Hell, 1200hp's no problem with a 540 and an m4. Aren't you making 1100+ with and M3 and a less then stellar intake design?

Looks like a good build list, the Callies Ultra rods are good too, and Diamond makes some really nice pistons. I'd go with an M4 and EFI, 14lbs boost should be good for 1350ish.

The big cubes aren't needed at the power level the op is looking for

Okay so build it off of the 9.8 4.5 bore block. At this level should I be purchasing the block with billet mains, or just the reguler one's?

Have you took a look at these heads yet?

http://www.profilerperformance.com/r...c-ported-heads

They are outperforming most Dart heads, a much newer intake port design, as well as a thicker deck.

I would just get regular mains if it was mine, and I would not go with to extreme of a stroke, as Smitty already said.

I was just reading through some of Dart's info, and they said the regular mains are good to 1500hp. So that should work. I like the sounds of the 555, that sounds like a nice package. I have never assembled a dart block before. Do the lifter bores need a bushing, or are they good to go.

Start with a Whipple lolol