NA KA24de compression boost?

[Rottie21]

I have a project all motor KA24de i'm building but i cant find any information on what compression the motor can handle. What's the highest compression anyone has seen an NA KA run (please keep in mind im building the motor with forged internals and ferrea valves). What's the largest bore I can go to on the KA 90mm, 91mm ??......also on another note....this is my first experience working with nissan (i used to be a ford guy) and the goal of this project is 250+ whp on the NA KA24de. Any help anyone can give is apprectiated. I look forward to becoming a part of this forum.

[SR20DETpower]

id run a 90 overbore and it can take a lot of compression, depends on the fuel and tuning......

[Rottie21]

i'd like to see 12.5:1 on pump gas using an oil cooler.......any thoughts?

[SR20DETpower]

it could be done, dunno what an oil cooler is going to do to help it lol, if you want to use street gas it all depends on how you are going to tune it. Throw on a standalone ECU like a Electromotive Tech II or a SDS system and have it tuned by professionals on a dyno with a wideband o2 sensor and it will take a lot of compression. Of Course that would cost a few thousand to do that, but you gotta pay to play in high compression or high boost.

Also your motor won't last as long with high compression, besides the pistons and block wearing out quicker from the stress, other parts such as bearings and tolerances will get messed up since it is so much harder to move the crankshaft with higher compression.

when installing an auto tranny you gotta move the crank via the flex plate, almost like a flywheel, and they make tools where it latches on and you can move the crankshaft, this is really hard to do on older 60's and so cars with higher compression then some of the new cars, you can really tell a big difference in the strain placed on the engine.

[Rottie21]

the oil cooler would be to keep the motor just a little cooler to keep the timing up......fill me in on a "wideband 02 sensor" if you dont mind....thanks

[SR20DETpower]

its a tool they use on dynos to figure out how good they are doing the "tuning" It lets em know if the changes they made to fuel map and or ignition timing have a good or bad effect then before. Its the preferred tool to use to tune an engine good. Some people just adjust things and see how the power curve changed on the dyno but that is a lot of guess and check, with the wideband o2 sensor they can tell if its tunning lean or rich throughout the rpm band.

[Rottie21]

makes sense....thanks for the clarification

[spitz7985]

i'd think 12.5:1 is possible on 93 octane. i don't know if that'll get you to 250 whp though.

[DWF Engineering]

I would imagine that 250 bhp would be attainable on pump gas. 250 net hp or whp I'm not so sure about. I personally wouldn't go past 10.5:1 if I were building it.