03-06 Evo Crank in a 92.5-99 7-bolt

[Strm Trpr]

So I recently discovered that Eagle's crank along with K1 Technologie's cranks share the same part numbers for both Evos and 7-bolt DSM 4G63's.
So this must mean an 03-06 Evo crank can fit into a 92.5-99 DSM 4G63.

According to Darren at FFWD, the Evo crank is much lighter than DSM 7-bolt cranks.
FFWD Connection - Race Injuns That Will Freeze Your Brain

On this page you will see that the stk DSM 7-bolt crank weighs ~35lbs and the stock Evo crank weighs ~30lbs.

Just wondering if anyone knew of this.
It's already been determined that the Pistons and Conrods from an Evo IX are forged components and fit perfectly.

So, can the crankshaft fit too?

 

[Evan K.]

I've been wondering the same thing.

My concern with the Evo pistons is the offset for the wrist pin. When installing the pistons in a DSM engine the piatons are 180 degrees off.

 

[DSM_PWR]

interesting fact....

Wonder if anyone will go with the Cosworth 2.2. stroker

 

[delta448]

Supposedly all 7 bolt crankshafts are interchangable. I've heard this from a few other reputable vendors other than FFWD, -who by the way I'd definitely entrust my engine to anytime even moreso than these other vendors I speak of.

The Evo pistons have been used with some success already. The only real concern is valve clearance and the compression height of the pistons. I haven't inspected a set of Evo pistons for myself, but others have reported that they have a slightly shorter compression height which would lower the CR significantly if used in a DSM. But as I said, I've not confirmed that.

I've been wondering the same thing.

My concern with the Evo pistons is the offset for the wrist pin. When installing the pistons in a DSM engine the piatons are 180 degrees off.

The Evo valve reliefs are obviously on the wrong sides of the piston with respect to the pin offset, but others with reasonable 272 duration aftermarket cams have reported no valve clearance issues for the larger intake valves matching up with the smaller exhaust valve reliefs on the piston. I would really strongly suggest that the pistons be installed with concern given to the pin offset way before valve reliefs. If the pin offset is wrongly positioned, then the con rods will be subjected to MUCH more shearing stress.

Peak pressure occurs shortly after TDC on a correctly tuned engine. The pin offset allows that pressure to act more perfectly along the long axis of the rod when the pin is offset. Piston side loading is also reduced.

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Rudimentary illustration, but you get the point. If peak pressure occurs at roughly 15 degrees ATDC, which it should to produce the best power, the offset pin makes it easier for the rod to withstand the stress by compressing it along it's center. The non-offset pin has the rod "leaning" more when pressure hits it's maximum.

 

[SBR Joe]

To put it simple. A 7 bolt crank, is a 7 bolt crank. Whether its a 1g, 2g, or EVO 7 bolt. The late 98 and 99 2g's had a split thrust design like the evos, but the difference is in the block.



Joe
SBR

 

[Strm Trpr]

interesting fact....

Wonder if anyone will go with the Cosworth 2.2. stroker

CP Pistons makes pistons for this exact set-up found here at MAP.
CP Pistons 4G63 94mm Stroke 9:1 Pistons - Modern Automotive Performance

Eagle 94mm crank.
EXTREME PSI : Your #1 Source for In Stock Performance Parts - Eagle Forged 4340 Chromoly Stroker Crankshaft (94mm): Mitsubishi Eclipse 92-99 7-Bolt

Any 150mm rods.
EXTREME PSI : Your #1 Source for In Stock Performance Parts - Manley Performance H-Beam Steel Connecting Rods: Mitsubishi Eclipse 92-99 7-Bolt

Same exact set-up as the Tomei 2.2L rotating assembly for Evo's.

I've always wanted to build the 94mm Eagle Crank/+3mm CP Piston/150mm Manley Rods = 2.2L, well with an 85.5mm bore, (.020" overbore) it's a 2.16L.

Magnus builds a 2.2L with their 92mm crank, 150mm rods and +2mm pistons.
It's actually a 2.14L with an 86mm bore, (.040" overbore).
According to Magnus, their 2.2L has a "Flat broad power band, our favorite all purpose motor".

Based off of this information, I'm very tempted to build the 94mm/150mm/+3mm 2.2L stroker set-up.

 

[delta448]

Chris, I'm right there with you salivating over the 2.2L, but I have a different opinion on just a couple things... the rod length mostly.

When I think of a 2.2L 92-94mm stroke sirius engine, I dream about insane midrange and top end power. I wander away to fantasyland thinking about superlight pistons, titanium rods and all the other parts that would allow the awesome geometry and displacement increase of a 2.2L to really shine.

Here's my humble opinion:
If you stick with a 63 block and 94mm stroke, I think the absolute best case scenario is going to a custom 153mm length rod with lightweight regular stroker pistons. Custom length aluminum (or titanium?) rods would be quite expensive I'd imagine though, if you could even find someone who'd make you a set. However, SBR does have custom Mahle stroker forgings that weigh an incredibly light 250 grams per piston... hmmmm. Anybody know what those 94mm stroke specific CP pistons weigh and what alloy they are? Not very much detailed info on that page... however they're likely much more economical for the average guy since there are off-the-shelf rods available for them.

Now it can really get interesting if you happen to have a 2.4L block with the extra deck height to work with. In my opinion, the best case scenario here is a custom 159mm rod and a piston with the stroker pin location and larger bore size. Now you're looking at a 2.26L with a 0.040" overbore. The real kicker though, is that you are extremely close to having the same rod ratio as a stock 2.0L 4G63, but have only ~10cc smaller displacement than a stroker 2.3L on a stock bore '63.

The stock 2.0L 63 has a rod ratio of 1.70 and the hypothetical 2.26L has a rod ratio of 1.69, unlike the 2.3L stroker which has a low rod ratio of 1.5. Basically, this hints that if weight is reduced on the rotating assembly over a 2L, the 2.26L bottom end could possibly safely rev even higher than the 2L and with more displacement. Extra helping of hugeass turbo anyone?

If you build a regular 2L with 150mm rods and forged pistons, you'll be able to take the bottom end to 9.5k rpm pretty safely. -Now how about building a 2.26L that saves weight by using ultralight pistons and rods? Anyone think we can make up the 570m/s difference in average piston speed at 9500rpm by knocking off some weight and/or using more robust rods?

 

[Strm Trpr]

I do like your idea of the high revving 2.2L in the 4G64 block.
I will build a 4G64 motor someday, but I'm a torque junky, so more than likely it'll be a 2.4L Longrod motor.

I do not drag race, I'm not good at it, therefore I despise it.

I'm addicted to road racing so a motor that revs up to 9500rpm just really isn't necessary.

I may just go with a 7-bolt 2.3L rotating assembly from FFWD and call it a day.
In all honesty, I don't need to rev past 7500rpm.

On another note, the 4G63 2.2L.

94mm Eagle Crank ~$700
Custom 153mm Rods ~$900
OTC 2.3L Stroker Pistons ~$500

85.5mm pistons and a 94mm stroke will yield a displacment of 2.16L with a rod/stroke ratio of 1.63.

On the other hand, Magnus says their 2.2L (1.63 r/s ratio) can rev safely to 9500.
92mm crank
150mm rods
+2mm pistons

And yet again a 2.2L using 150mm rods will yield you a rod/stroke ratio of 1.6.

I really think the 94/150/+3pistons would work just as well as the Magnus set-up.
IMO the extra .03 you'd gain from going with longer rods just isn't worth the extra $$$.

Simply put:
94mm crank ~$700
150mm Eagle H-Beams ~$300, I prefer to use Crower Rods or Manley Turbo Tuff Rods, so ~$700
CP Pistons ~$500, Any piston shop will make a custom set for you, just gotta show them the $$$.

2.2L rotating assembly for $1500 ~ $2k, depending on choosen components.