KA24DE Head Cut Open For Porting

[Nismo_Freak]

You are flow benching the head with nothing on it correct? As in no pipe on the exhaust side and no intake manifold.

If I were messing with that head based on the info you've provided I would leave the intake side alone. I don't see too much that could be done to improve flow from just looking at the cutaway. Especially since you might alter how the wet flow interacts with the valve, making a higher flow number equal less power.

[Aaron_9349]

Yes, these numbers are with no manifold on either port side. As far as the intake side, I guess I will find out tomorrow when I flow the intake on the stock head to compare to the ported head.

NOBODY KNOWS THE VALVE INSTALLED HEIGHTS?

[Dammitboy]

Any word on those flow #'s yet? I'm really hoping those first #'s were off a bit. That would be terrible news if they were right. I've done the same work with a spare head I was planning to use for turbo use, I'd be real dissapointed if I lost flow too. Kevin

[Aaron_9349]

Ok, been a while, but things got a little hecktick moving out of wyoming, but I'm back now in Wisconsin and have the internet up and running.

AND... GOOD NEWS... The head I originally flowed was off, majorly. Infact the flowbench itself took a crap on us, so I re-flowed the stock head and ported head on a different, and much newer machine and got some very good consistant readings. I have new numbers for before and after the port job and valve job. Plus I also have specs for the valvetrain that may be usefull to others doing their own valvetrain work. I will be posting these today but was thinking a new thread may be better. I also have finished pics of the head, and may be putting some aftermarket cams into the head in the near future (maybe another how to thread).

This thread started just on the pictures of the head I cut up, and has grown into a HOW-TO port thread. If any moderators would like me to start a new thread or a seperate one, please let me know and I will better organize the information.

Ok, well now the info...

[Aaron_9349]

STOCK HEAD FLOW NUMBERSoff a 95 Nissan 240SX KA24DE w/ ~ 95k

Intake CFM at .XXX" of lift:

.100" = 99.3 CFM.200" = 171.1 CFM.300" = 223.4 CFM.400" = 241.8 CFM.500" = 243.6 CFM

This is lower than the readings before. But, as you can see it peaks at just over .400" lift, any larger a lift may be unneccessary unless boosting.

Exhaust CFM at .XXX" of lift:

.100" = 75.8 CFM.200" = 144.5 CFM.300" = 173.9 CFM.400" = 182.9 CFM.500" = 183.6 CFM

This one also peaks at right around .400" lift, just a hair lower maybe than the intake side.

I believe that my initial test was incorrect either due to the machine itself or my incompitence. Either way, these new numbers were calculated on a newer machine and done at the same time as the ending post porting numbers with the same exact hardware and measureing tools, so they should be accurate.

Enjoy!

[Aaron_9349]

FINAL FLOW NUMBERSAfter the Port & 3-Angle Job

These numbers are the average for all 4 cylinders done on the same machine with the same tools as the stock head was measured.

Intake CFM at .XXX" of lift:

.100" = 85.7 CFM.200" = 166.3 CFM.300" = 225.3 CFM.400" = 255.0 CFM.500" = 260.5 CFM

This indicates an aproximate gain of 15-20 CFM on the intake side when compared to a normal cylinder of 243.6 CFM max and my new max of ~260.5 CFM. This is very acceptable and should provide some more power easilly.

Exhaust CFM at .XXX" of lift:

.100" = 84.9 CFM.200" = 136.8 CFM.300" = 172.8 CFM.400" = 183.6 CFM.500" = 188.1 CFM

This shows an increase of ~ 5 CFM on the exhaust side. Not very significat considering I took much more out of the exhaust side than the intake. But, there is still an increase which is good, and the intake side counts the most when you're looking for power.

Overall, I'm satisfied with my port and valve job and I should feel a nice boost in strength once its on the car. I have some final pics of the head but can't find them so I will post later. Also have more valvetrain specs for later.

[gawath]

Great Job Aaron.

[hannibal]

Good info. I missed this the first time around, but I'm glad I caught your update.

[WI_S14_Goldie]

Any updates?? How does it feel?

[distantcrowd]

Great job those cross sections of the head will really help me when i start to port and pollish my heads again!!! i have done a couple but never had the saftey of knowing exactly where the water jackets were...

Did you do any gasket matching and or work to the manifolds you can really take some material out of the intake but i dont have a flowbentch to test what gains i may have accomplished...

[diegs88]

are all of your results at 28" of water? what flow bench did you use?

[WDRacing]

are all of your results at 28" of water? what flow bench did you use?

Probably won't get much of an answer. The thread is OLD...lol.

WD