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Old 06-27-2018, 07:55 AM   #7 (permalink)
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Gaptooth (retired) - '00 Honda Insight
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I'm guessing few to none here know much about different versions of the Honda K20 and K24, but I figure I'll throw this out there anyway, in case anyone has any useful feedback:

My understanding:

+ high revving, slightly lighter, shorter engine (fits better), barrels of fun, short runners (fits better), well understood and relatively easy
- expensive, less torque, probably worse gas mileage (all else equal)

K24A2 (pre-2006)
+lots of torque, probably better gas mileage, less expensive, well understood and relatively easy
-lower rev limit (still plenty), heavier, probably hard to find one without a lot of miles, long runners (might need to cut radiator support)

K24Z3/Z7 (~2006-2012)
+ probably cheapest of all since nobody wants integrated header, easy to find low mile, wider powerband
- Aftermarket engine management might be absolutely necessary, since it's DBW. Adds cost overall, unless I go with an aftermarket ECU to begin with

K24W/V7/W7 (2013+)
+ Most torque of any K engine by a lot, probably best fuel economy, easy to find cheap low mile engines, crazy high compression ratio
- I have no idea about DI, probably would need entirely new fuel system? Probably not a well understood swap even if it can be done, so $$$$$

Not currently considering the lower revving, lower compression ~160HP K20's and K24's.

Some questions I have rolling around in my noodler:

Are the mounts the same on the newer W and V Earth Dreams motors? Should I rule those out entirely because of direct injection? Has this ever been retrofitted before? This is probably too ambitious, but I'm curious about them at the very least.

What are the major hurdles of keeping the factory ECU to save money? I'm willing to bet I can get away with this with the early K20A/K24A, but I don't know if it would be possible on the newer K24Z, due to drive by wire.

Are there any engine and transmission mount differences for the various K engines and transmissions? Are they all interchangeable? Does any transmission mount to any engine?

Am I correct in thinking the K24A's have VTEC on the exhaust cam, whereas the Z's do not?

I'm undecided on whether or not to go with aftermarket engine management, because I don't know where I'd find a tuner who knows how to tune for lean burn and fuel economy. On an engine with VTEC on both intake and exhaust, AND variable timing, AND variable length intake runners, trying to tune it myself sounds... difficult.
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