102mm Crank or 100mm Crank?

[ProjectTalon92]

On a previous thread, i was in a conversation with another member and he said that i shouldn't go with a 102mm stroker crank? now i'm not sure, but i wouldn't think that would make that much of a difference. Would 2mm make a whole lot of difference when decideing which crank i should buy? and does everyone else that wouldn't be a good idea to buy a 102mm stroker crank?

 

[TunaTalon]

See http://www.dsmtuners.com/forums/str...acement-various-combinations-bore-stroke.html for a table of displacements for various bore and stroke combinations.

The 102mm stroke crankshaft will need the taller block of the 4G64 to fit and then will need stroker pistons and custom 155mm rods.

Compared to the 100mm crank in a 4G64 with stock bore you will gain only about 2% more displacement. Compared to the 100mm stroke you will lose only about 60 RPM for max piston acceleration (as referenced to the 2.0L)

The beauty of tuner cars is that everyone can build up a car to their own taste. For my taste the 102mm crank adds a lot of sour complications for very little sweet torque.

 

[ProjectTalon92]

that's a good way to look at it. i know that i'm going with an aftermarket crank. i know i can get a OEM 2.4L crank easy, but for my goals i'm not sure it will hold up. and there are numerous stroker cranks that i have been looking at. So all in all a 100mm crank would be better over all? one of the cranks i have been looking at is an eagle 100mm crank shaft.

 

[TunaTalon]

The 100mm crank is the "tried and true" solution. The 102 mm stroke will need either custom rods or custom pistons. You post mentioned the crank only but there are kits on the market that handle the different rods and pistons for strokes other than 88mm or 100mm. Purchasing a kit can pass off some the complexities to the vendor but there is still very little to torque gain with the extra 2mm stroke.

For what it's worth, I have a 100mm Eagle crank in my Talon.

 

[delta448]

Brian Crower makes stroker kits for both the 4G63 and 4g64. The 102mm crank is for the 4G63.

 

[98gsspy]

The 102mm crank is for the 4g64.

 

[delta448]

I don't have personal experience with the Crower kit, but their site states the 102mm crank is intended to be used on the 4G63. I'd imagine their kit uses the maximum stroke possible in a 2.0 block. No doubt it would likely have less clearance problems on a 4G64 however...

The BC stroker kit for the Mitsubishi 4G63 engine platform incorporates a 102mm stroke, 7 bolt crank. Depending on bore size that you decide, the BC kit will take you up to a 2.4L with 86mm bore.

I think that it probably doesn't matter whether you use a stock 100mm 4G64 crank when stroking a 4G63 over the 102mm, although the BC crank is likely a higher quality. If you want max displacement most people would just skip right on over to the 4G64 and build it instead.