I have a complete evo IX head and bare block (4G63). Plan is to use 94mm crankshaft for a 2.158L (85.5mm bore).
Redline will be 8,297 rpm, if we limit piston speed to 26 m/s. I'm looking for best power band and not biggest power in a 500 rpm range. LOL
I'll add more info as I figure it out.
"Group" build is in reference with all your comments and suggestions to help guide me on the best path. Looking forward to reading on your tried and true options

 

What's your goal for power and what are you going to use it for?

 

Update:
Crankshaft:
I ended up going with K1 Billet 94mm crankshaft
​​​​K1T 032BC940



Rods:
Ended up buying off the shelf Carrillo 150mm with Carriage Bolts



Pistons:
Ended up going with Manley 618005CE-4 pistons. It didn't look like what I was seeing in pictures (surprise! Pictures don't always show what you're buying, that's so stupid!). Fortunately, these pistons are beefier.

 

I'm planning for DD with weekend warrior duties. I think something to maximize FP MHI Red for broadest power band. 91 octane / E85 setup that is stealth enough to pass smog police visual inspections. I'm aiming for 600whp/500tq on E85. And potential to make 750whp/600tq.

 

I would call English Racing for the rods and Pistons. If you're going to limit RPM to 8300, stick with a 150mm off the shelf rod and get a custom piston with the appropriate pin height. It'll save you some money vs using both a custom rod and a custom piston.

 

I thought we should limit piston speed to 26 m/s for longevity? That's why I calculated 8300 rpm. Isn't there a problem from going faster? If not, then I'd like 9000 rpm limit!

 

Thanks Sean. I now see why I couldn't find 153mm rods.

 

The 94mm or 100mm crank makes a great street car engine and moderate levels. I would go with a lightweight Carillo 150mm rod, a .230 or .250 wall pin and a 9:1 compression ratio for 91 octane. An MHI housing isn't going to flow well above 7000 so don't worry about trying to turn it past 8000. The 100mm crank would make the situation worse because of increased backpressure.

 

Good point Tim, I'll price out all options. If I'm not going to make more power after 7000 RPM, maybe 100mm crank makes more sense and just get the 4.1:1 final drive. And port out turbo hotside.

 

I really like the to have the wrist pin higher to reduce the load on the rings (I truly believe they see some load from keeping the pistons going up/down caused by the rods swinging back and forth).

 

That assumption is correct. A higher wrist pin reduces the lever arm produced by the rod pushing/pulling at an angle.

 

you know, you're the first to agree. Better get your flame suit on!

 

The rod ratio with 94mm crank and 150mm rod is fine. And the non-custom rod saves a lot of money.

 

I've been out of school way too long! Can someone calculate the centripetal force Carrillo rods exert on crankshaft at 8500 rpm? I came up with about 9,500 pounds (566 g per rod). Add the piston of about 4,900 pounds (292 g per piston) and we get 14,400 pounds of force that crank pulls at start of suction stroke. So each rod bolt is pulling 7,200 pounds? This can't be right.
And at 9000 rpm, I get 16,100 pounds, so 8000 pounds per rod bolt. Isn't the cross-section of a rod bolt about 0.11 sq in for 3/8" bolt? 200 ksi (for ARP2000) × 0.11 sq in = 22,000 pounds?

 

You're over thinking this. The 94mm stroke is fine at 9000rpm with a 150mm rod. The 94/153 is fine at 9600 (for drag racing anyways, probably would keep either below 9000 for road course work). Regardless, with the red, it's going to make peak power around 7-7500, and be falling off by 8. You won't want to rev it past 8.

And if you're only going to throw a red at it, eagle Hbeams will more than handle what the red can make. They're good to about 570wtq. The red won't make more than about 525wtq.