highest compression with R4 cam (SOHC)

[shinrekka]

Even though i havnt owned a 240 in a long ass time, and its gonna be awile till i pay off my new car I still dream of different builds i'd like to do in the future. For my next build i'd like to go all motor SOHC. I know blah blah blah i dont care what you have to say if you think its a bad idea, no i dont want turbo, been there done that.

Alright heres my question, what is the highest compression i can go using a nismo R4 cam. I'd like to run 10:1 but im not sure what the limit is before the pistons hit the valves.

Heres the potential set up
Nismo R4 cam ( possible port + polished head)
rebuilt bottom end, 10:1 compression pistons (maybe overbore?)
obx header, test pipe, 3" apexi N1 (yeh i know its gonna be stupid loud)
custum intake with K+N filter
Fidanza flywheel, UR crank pulley
JWT ecu

Should be good for 170hp I would think?

[shinrekka]

No one knows? No one has an R4 cam or done high comp in a SOHC?

[aa87]

My friends done it but only made 128.4 to the wheels. We laugh at him because he could have spent that money on an sr with all he put into the ka. This is without a tune or anything but meh.

[KA-T_240]

custom intake manifold would help. also, if you can fab, or have connections, some sort of a equal lenght header can help. go .40 over you wont have issue with it, built head for higher RPMS. The main way to gain HP is more CI, more RPMs, More air.


My friend had some crazy ass header on his d16, it gained 16.5whp over a ebay header. same dyno same day.

[stinky_180]

you should plan on doing a lot of work to the head, airflow is the weakest link on the KA motor

[gripstr]

you'll top out at 150 with that setup imo

turbo that biastch!! single cam boosted is :boink:

and oh i forget to add, it will probably cost you the same amount.

[shinrekka]

My friends done it but only made 128.4 to the wheels. We laugh at him because he could have spent that money on an sr with all he put into the ka. This is without a tune or anything but meh.

-I couldnt care less if you laugh at your friend or not, i wasnt asking your opinion. And Im not going turbo again and if I was I wouldnt want an sr, much rather turbo the SOHC.

-The head of course will be port and polished if budget allows. I wont be doing any valvetrain work other then what I need to for the cam.

-As far as tuning is concerned, I have heard jim wolfe tunes conservitivly so i dont think I will be going that route, maybe at first but I just may go with carbs and have them professionaly tuned.

-Im going to document and dyno everything I do with the car. So everyone will know what each modification makes to clear up all the false information out there. I dont plan on breaking 200hp to the wheels but im going to try to get damn near close to the crank.

-Also mach5camaross, I do have a couple connections and can get many things custom fabbed but that may be far down the line. As of now im going to go with whats on the market and what is affordable for those that want to have fun on a budget. Most people cant or dont know were to get custom intake manifolds or headers made. Kooks custom headers is right around the block from me, but most likely i will be going with OBX, i have had good luck with there header on other cars.

[decco]

If you can get some custom fab work done, you should make a ram air intake on your bonnet, like how the Ferrari's and some other cars do it. So when you're up to speed, it allows the air to get forced into the intake, acting like light boost.

Off the top of my head the Ferrari Barchetta is one that does ram air.

[stinky_180]

-The head of course will be port and polished if budget allows. I wont be doing any valvetrain work other then what I need to for the cam.

-As far as tuning is concerned, I have heard jim wolfe tunes conservitivly so i dont think I will be going that route, maybe at first but I just may go with carbs and have them professionaly tuned.


you should consider solid lifter conversion from hybridka, they're on special order however. valve float can be pretty bad at constant high RPMs

you can tune the sohc yourself for a lot less than what jwt charges. hybridka.com ECCS-TEC FTW!!!!!

[Mrpickles15]

Here's an idea from our good friends at Wikipedia.
http://en.wikibooks.org/wiki/Nissan_240SX_Performance_Modification/KA24DE_and_KA24E/ITB's

Happy little write up on a few hundred bucks worth of crazy NA power for the KA24E/DE. As a disclaimer, I just googled this, I didn't write it.

[johngriff]

Horrible write up.

Baller write up located here:
http://forums2.freshalloy.com/showthread.php?t=175979

[shinrekka]

Hey, do you guys think i should do this in a stanza, 240, or pickup? I have the option for all 3 right now.