SR intake cam deposits

[Jorg.V]

I just bought a sr20 front clip and while replacing the gaskets I found a lot of deposit build up on the intake cam only. The exhaust cam is perfect with zero buildup. The deposits are black and not gooey but hard and crusty. Does anyone know what causes this?

Also, the intake cam lobes have a significant ridge(maybe 1.5mm high) on the edges like maybe rocker contact has worn down the lobe. The exhaust side doesn't have them. What would cause only one cam to wear like this?

[jspaeth]

I just bought a sr20 front clip and while replacing the gaskets I found a lot of deposit build up on the intake cam only. The exhaust cam is perfect with zero buildup. The deposits are black and not gooey but hard and crusty. Does anyone know what causes this?

Also, the intake cam lobes have a significant ridge(maybe 1.5mm high) on the edges like maybe rocker contact has worn down the lobe. The exhaust side doesn't have them. What would cause only one cam to wear like this?

Not sure about the buildup. The cam lobe wear is probably due to improperly torqued cam caps, or someone reassembled the head without putting the shims back in the right spots.

Are the ridges on BOTH sides of the cam lobes, or only on the edge facing the front or the edge nearest the rear?

[Jorg.V]

The ridges are on both side edges of the lobe and are about 1mm wide and 1.5mm tall. Where are the shims? I have a pic of the ridges but my attachment quota is maxed.

[jspaeth]

If the ridges appear even on both edges of the cam lobes, then the rocker arms are probably shimmed properly and contacting the cam lobes the right way.

Perhaps the deposits combined with the worn cams just mean that it's an old engine in need of some rebuilds and stuff.


I have OEM S13 SR cams in really good condition I cansell you if you want to put some better ones in (with no wear).

Let me know.

Also is this an S13 or S14 SR?

[Killa_D]

also have a stock intake cam in pretty good conditions for 20 bucks shipped so lmk if your considering buying a new cam.

[Sileighty_85]

that lobe looks ate the hell up, make sure you got oil puressure and oil flow throught the squirter

[codyace]

that's old crappy oil on the intake cam. probably due to a few irregular oil changes in that motors life. Change new cam squirters (order them from a 97 Sentra), pull that cam out, and try to clean as much of that shit oil as possible.

[s14unimog]

that lobe looks ate the hell up, make sure you got oil puressure and oil flow throught the squirter

My thoughts exactly, since its on one side, I bet you have a gunked up oil rail (or what ever its called) The damage to the came lobe is likely due to lack of lubrication. Its crusty b/c it was baked on there when the cam shaft was blisteringly hot. When you replace that cam shaft, make sure you don't have journal damage. Its probably unlikely since they are lubricated from internal oil passages.

[Jorg.V]

Im pretty sure that's what it was. I removed the oil squirter tube and soaked it in brake cleaner then blew out all the gunk with an air nozzle. It was clogged pretty bad. I did the same with the other side too but it wasn't bad. The shop that I purchased the engine from is sending me another cam on monday. Thanks for the help guys.

[Sileighty_85]

Im pretty sure that's what it was. I removed the oil squirter tube and soaked it in brake cleaner then blew out all the gunk with an air nozzle. It was clogged pretty bad. I did the same with the other side too but it wasn't bad. The shop that I purchased the engine from is sending me another cam on monday. Thanks for the help guys.

I hope they are sending you a new rocker arms too. They are gonna be equally torn up also