bigger valves for a ka24e

[fo0manchu]

Ive searched the forums and read a lot of posts about modifying the ka24e, but Ive never came across a post about intalling bigger valves.

Is this possible for this motor? benefits?

[TomsMR2]

gives more top-end, less low-end.

[singlecamhonduhkilla]

TOMSMR2 DO U HAVE A PICTURE OF UR CAR OR CARS? IM JUST CURIOUS BECAUSE U SEEM TO KNOW ALOT ABOUT CARS AND WAS CURIOUS TO SEE WHAT U DRIVE.. MAYBE PICK UP SOME IDEAS.. THIS ISNT A FLAME SERIOUSLY I REALLY WANNA SEE WHAT U DRIVE.JOE

[fo0manchu]

would this allow the engine to rev higher, since the head is more free flowing now?

and would getting bigger valves benefit a N/A engine more or would you see more benefits with a turbo application?

just seeing if it would be worth looking into doing, thanks.

[JJ240]

Yes it would benefit both engines. Just like stated before It will open up your top end alot since you can flow a higher volume.

[TomsMR2]

TOMSMR2 DO U HAVE A PICTURE OF UR CAR OR CARS? IM JUST CURIOUS BECAUSE U SEEM TO KNOW ALOT ABOUT CARS AND WAS CURIOUS TO SEE WHAT U DRIVE..

dude, i drive an MR2 :lol:

[SSS]

I'd maybe only go 2mm bigger on the exhaust side, and leave the intake as is for a street motor.

[C-Kwik]

would this allow the engine to rev higher, since the head is more free flowing now?

Revving higher rarely has as much to do with more flow as it does being mechanically able. You can get higher lift cams to get more flow. Some of the limiting factors to revving higher tend to be valvetrain weight/spring stiffness, poor harmonics/balance, not enough oil flow at high RPM's to keep pressure to the con-rod bearings, and con-rod tensile strength.

[TomsMR2]

with the oversquare KA engines.. id be scared to go past redline anyways.

[C-Kwik]

I agree. But JWT says the KA24DE is good up to about 7500 RPM before the poor harmonics start causing problems. The S13 KA24DE's have a 6900 RPM redline. But power dies much sooner. A cam designed for better top end would certainly help make use of the available redline. Perhaps even a slight bump up to 7250 would still be safe while allowing more power. Not exactly on-topic, but I'm sure the SOHC has similar issues.

[RedShred]

I was going to enlarge the exhuast valve on mine. But my machinist found it cost restrictive and found that .020 is as much as he'd feel comfortable enlarging the seats. We decided to port it more and add more lift to the cam.

C-Kwik has a great point.My car pulls to revlimiter easily, not running out of breath at all. Before teh big cam and Port work, I ran a basically stock KA with about 10:1 compression and it would run out of power at about 5200 rpm.

I can tell you that a good cam and PnP will snap your KA to attention. I spent about 400 bucks for my head work to include the cam.

[fo0manchu]

thanks for all the insightfull replies. I probably look more into the pnp and cam.

[SSS]

I can tell you that a good cam and PnP will snap your KA to attention. I spent about 400 bucks for my head work to include the cam.

I agree 100%.