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Is a 2.5l stroker crank worth it?

dannyman742

Member
Joined
Jun 17, 2021
Im building a 93 240 drift car and im going to do rods and pistons. I thought about swapping the crank while in in there for 86mm and 2.5l of displacement. How much difference does this 0.2l make throughout the powerband? And is it worth it?

Specs:
Ported 531 head
93 squirter block
Yoshi rods pistons
Holset he341 30 psi
Enem k15 turbo cam
E85
Haltech 1000
Kl racing turbo manifold and cast intake manny
Do88 intercooler with 2.5 inch piping
 
Im building a 93 240 drift car and im going to do rods and pistons. I thought about swapping the crank while in in there for 86mm and 2.5l of displacement. How much difference does this 0.2l make throughout the powerband? And is it worth it?

Specs:
Ported 531 head
93 squirter block
Yoshi rods pistons
Holset he341 30 psi
Enem k15 turbo cam
E85
Haltech 1000
Kl racing turbo manifold and cast intake manny
Do88 intercooler with 2.5 inch piping

It's also a forged steel crank btw...
 
I'm not sure anyone has any real data to answer the question but my thoughts on this:

I bought a complete boat engine for $100 and the 2.5l crank is sitting in my shed. If I ever have to build another engine/replace my current forged rods & pistons I'll certainly take advantage of it and build a stroker. I'm not sure I would spend ~$500 to buy a crank from someone else, though.

side note: I have 158mm rods in my 2.3l with Wiseco pistons and the lighter pistons make a difference in how quick the car revs over the regular 156.
 
I'd comment, but really, have no experience with a stroker motor.

I do have a B20 in my old car with another .2(ish)L of displacement added to it, but that was with bore, not stroke, and AFAIK a stroke change will make more of a difference than a bore change. The .2L of added bore displacement didn't really add much in the way of peak HP, but did add torque, especially down low. And I think it has continued to benefit the HP as I've added other mods which raised the torque range.

But that's normally aspirated, and I think the effects of .2L on a boosted motor would still exist, they'd just be relatively less important than all of the other aspects - efficiency of the turbo, how much boost, intercooler, intake manifold, etc.

In other words, yes, it would make a difference, but so would turning the boost up another psi.
 
Expect a specific output increase commesurate with the change in displacement. I'm swapping in a 2.5L block into my car, which would correspond in a ~20 lbs-ft bump in the 2000-3500 range where my current engine makes very little torque. You can expect a minimal improvement in spool time out of that turbo also.

If you are already forking over money for rods and pistons, figure out whether the incremental cost increase is worth the nominal performance improvement and go from there.
 
Show me them 8000 RPM pulls from your tractormotor :cameron:

wait-ben-hamilton.gif
 
~8% power increase from displacement alone + ~4% torque and power increase from longer stroke.
 
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