I've seen 150mm rods with 100mm stroke. But would a 94mm stroker and 156mm rods be a better option to reduce crank harmonics and have a revvier 2.3 displacement?

 

94mm crank with 153mm rods and an appropriate pistons(in a 4g63) would be the best option, bump in tq and still have the ability to rev high without any of the harmonic issues associated with the 2.3

 

94mm crank makes a 2.2

Can do custom 153mm rods with a shelf piston, or the more affordable route is a custom piston and 150mm rods. I do a lot of 94/150 motors, they rev to 9500 without issue.

Or you can do a 4g64 block with 156mm rods.

 

What everyone else said is correct.

156mm rods would be nice but you need a 4g64 block. Only disadvantage of the 4g64 is that you have a bigger bore thus weakening the cylinder walls. You could always sleeve a 4g64 and run standard size pistons but, it would cost more.

As for 153mm rods, you can get Nitto V2 i-beams from australia. USD is super strong at the moment so you can get them for like 900USD after conversion. I talked to Nitto and they said they’re rated for 350-400hp per rod at the crank but they’re pretty heavy and weigh 676grams. They have the V1 rods that only weigh 607grams but are rated for 250hp.

Nitto also sells pistons for their 153mm rods, but they’re made by CP.

 

You do not sleeve a 4g64 for standard pistons.

The 4g64 block works well to ~1000whp with proper head sealing methods.

 

nope... manley has a kit for 156mm rods in a 94 mm configuration in g63 block...

 

I see, I remember seeing a few big power 4g64 sleeve their blocks with 85 to 86mm pistons. Not sure if they were O-ringed or running those stopper head gaskets.
I assume they were sleeved for longevity and machinability in the future.

 

I am surprised they would make 156mm kits for the 4g63. Would the piston pins not interfere with the rings? You would also have less compression height.

 

I was thinking more along the lines of using a 2.3 piston. But instead of 100mm stroke go 94mm and put the 6mm the crank would have had into the rod length to make up for the 100mm to have a better rod ratio.

Or is that not a possibility. Either way ill be going a 2.3. Moreso thinking out loud with those more knowledgeable

 

You can change the rod length by the change in stroke. So a 2.3 piston needs a 153mm rod on a 94mm crank.

 

would that be a better combo over a 100/150?

 

I paired a 159mm rod on a 94mm crank in the 4g64, used these pistons - K667M87AP with no issues with pins and rings.

 

Yeah on a 4g64 but not a 4g63. The 64 has 6mm more deck height.

 

2.3 piston on a 94mm crank will give lower CR than on a 100 mm crank

 

Yeah. A 9:1 piston will be around 8.5 depending on final combustion chamber volume and home much was removed from the block deck. A 10.5:1 piston will end up in the high 9's.