Cam Question

[ZartaN]

When changing cams, is it necessary to replace the rocker arms as well????Specifically PDM stage II regrinds.....Thanks for everyones help:ylsuper

[Open4Cycle]

Yes it is best to replace rockers because the rockers wear to each cam lobe.

[Aries]

yep yep yep.

[JNM240]

True, i spent more on the new OEM rocker arms than i did on my Nismo camshaft. But its worth it for it all to last and wear properly together.

[95_240sx]

Since when does the KA engine have rockers?

Rick

[Open4Cycle]

Well let us clarify. If your changing THE cam in the KA24E then it is best to replace the rockers. There are 4 different kinds of rockers you will buy to replace all 12. There are 2 types for the intake side and 2 types for the exaust side. By the way anyone know what the specs are on a R4 camshaft?????

[TrunkMonkey]

By the way anyone know what the specs are on a R4 camshaft?????

.402" lift and 270 degrees duration on both intake and exhaust.

-demetrius

[JNM240]

:P

[Open4Cycle]

Anyone know what this cam (R-4) is supposed to be set on? I.E. Open close and or centerlines? Nissan didn't send the cam card with the cam for some reason.

[JNM240]

I dont understand the question. Are you asking how you degree it? It is a drop in with a lot of work. If you do not have a air flow meter buffer (like the HKS Super AFR) then you will want to get the adjustable cam gear and advance it 4-6 degrees. This will loose some of the power band but it wont stall out when you stop. If you do get an air flow meter buffer then set the cam at 0 degrees (drop right in) for the most power.

What is happening is the overlap is causing huge fluxuations in the incoming air flow meter signal to the ECU. The car will run but coming to a stop it will stall out every time. To counteract this, either advance the cam to take up some of the overlap, or buffer this incoming air flow meter signal. Im basically building my engine around this camshaft. But the HKS Super AFR did the job.

[Open4Cycle]

I wan't to know where the cam was designed for the Intake and exaust valves to open and close at in relation to crank degrees. When advancing the cam like you suggest you will not lose some of the powerband you will lower the RPM of where it is at.

[JNM240]

Im sorry, you are correct. I meant to say your powerband will move lower in the RPMs if you advance the cam. As for your question i did not recieve a cam card with mine either so i do not have the answer. Did you get one and are having a hard time with it or something?

[Open4Cycle]

No I didn't receive a cam card. I want to know what their baseline is. Just because someone said drop in doesn't mean that its going to be what they ground it to be after you install it. If the pin location or keway in the sproket is off .010" then the cam is off 1 degree. So add up all the tolerances from cam lobe grinding, cam sprocket manufacture, crank sprocket manufacture, crank woodruf key location, distance from cam to crank (for example milling the head), and chain length. Now do you understand why I want to know where they intended for it to be set? I have it set where I like for it to be but like you said above I may have trouble with the ECU.