Displacement for various combinations of bore and stroke

[TunaTalon]

Several recent threads have involved different combinations of bore and stroke and the effect of increasing the bore above stock. As penance for copying bad data from a vendor site to this forum I submit the following table summarizing the displacement of all combinations of crankshaft and piston offered by Magnus and Brian Crower. The rod lengths were calculated to fit the blocks and some may be custom lengths. All listed piston sizes are available but stroker versions with the higher pin may be custom on some sizes. As a crude measure of maximum RPM capability the last column is the RPM for the same peak piston acceleration as the stock 2.0L at 8000 RPM.

Note that peak piston acceleration is only one measure of the ability of an engine to Rev.
The 2.6L (2.579) engine with a 106mm stroke and 88mm bore will reach a mach number of 0.51 through the valves at 6195 RPM compared to 8000 RPM for the stock 2.0L. Above 0.5 mach through the valves, power starts dropping off until the sonic wall is hit at about 0.6 mach.

The ‘+’ or ‘*’ symbols indicate either stock pin location on the piston or raised 6mm as in the stroker pistons.

[Strm Trpr]

I know this is old, but you may want to add the 94mm crank from Eagle.
You can use 150mm rods and CP Pistons (Modern Automotive Performance has them) makes an OTC piston for this very set-up, the wrist pin is moved up 3mm.
Which is a 1.6 rod ratio.
I may build ^^^ motor.
Magnus reports that their 2.2L is the favorite all around motor with a wide flat powerband.
Magnus' 2.2L is actually a 2.14L.
92mm crank, 150mm rods and +2mm pistons 1.63 rod ratio

Another combo with the 94mm crank would be to use 153mm rods and 2.3L stroker pistons, i.e., wrist pin moved up 6mm, which is a 1.63 rod ratio.

The 94mm crank can also be used in 7-bolt 4G64's for a displacement of 2.2L.
94mm crank, 156mm rods and +3mm pistons 1.66 rod ratio
94mm crank, 159mm rods and +6mm pistons 1.69 rod ratio

[TunaTalon]

Right you are. While reading your recent post on that combination this olde thread came to mind, but I thought no one ever sees it. The spread sheet is still somewhere on this machine. I will try to excavate it soon.

Anyone else have other combinations in mind? The hard part is digging up the old excel file and re-learning how to use it. Adding more combinations is a kick in the pants.

[Artago]

Just so I understand this.

If I have these pistons on a stock 4G63 crank:

Slowboy Racing, Inc. :: Mitsubishi :: DSM :: Engine :: Pistons :: Mahle Pistons :: 2.0L 7 Bolt Pistons :: Mahle Motorsport 2.0L 7 Bolt Piston

Bore - 86mm ( .040 )
Stroke - 88mm
Rod Length - 150mm

Does that mean that my displacement is 2045cc?

Thanks,

Tom

[dylnwit]

Yes, or at least that's what I'm getting from it too

[Boosted98gsx]

Epic chart! Vote for sticky in stroker tech!