SR intake cam deposits - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Jorg.V · 12-03-2009, 08:42 PM

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 · 12-03-2009, 09:30 PM

Quote:

Originally Posted by 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?

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 · 12-03-2009, 09:41 PM

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 · 12-03-2009, 10:28 PM

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 · 12-03-2009, 10:34 PM

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 · 12-03-2009, 11:38 PM

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

codyace · 12-04-2009, 08:46 AM

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 · 12-04-2009, 01:30 PM

Quote:

Originally Posted by Sileighty_85

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 · 12-04-2009, 03:36 PM

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 · 12-04-2009, 04:03 PM

Quote:

Originally Posted by 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.

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

12-03-2009, 10:28 PM	#4
jspaeth Nissanaholic! Join Date: Mar 2006 Location: Philadelphia suburbs Age: 39 Posts: 2,347 Trader Rating: (7) Rides Gallery: jspaeth Feedback Score: 7 reviews	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? __________________ Daily driven

12-03-2009, 11:38 PM	#6
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	that lobe looks ate the hell up, make sure you got oil puressure and oil flow throught the squirter __________________ 後輪駆動車１番 1989 Built SR GT2871R -363whp 1998 S14 W/RB25- 250ish (For Now) 1986 SR86 - 200ish 1990 R32 GTR - 320hp Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html Don't Buy XS-Power or SSAC Shit

12-04-2009, 08:46 AM	#7
codyace Post Whore! Join Date: Dec 2004 Location: Poconos, PA Age: 39 Posts: 8,030 Trader Rating: (58) Feedback Score: 58 reviews	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. __________________ *Want Air Conditioning in your SR20 Swapped car? Check out www.sr20acbrackets.com for more information! Quest Alternator Conversions for SR20!* Check my Group Buy! Tired of lousy internal gates? Go external wastegate with one of my manifolds, Check out my group buy

12-03-2009, 09:41 PM	#3
Jorg.V Join Date: Dec 2009 Location: Braselton GA Posts: 3 Trader Rating: (0) Feedback Score: 0 reviews	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.

12-03-2009, 10:34 PM	#5
Killa_D Zilvia FREAK! Join Date: Nov 2006 Location: nowhere Posts: 1,463 Trader Rating: (39) Feedback Score: 39 reviews	also have a stock intake cam in pretty good conditions for 20 bucks shipped so lmk if your considering buying a new cam.

12-04-2009, 03:36 PM	#9
Jorg.V Join Date: Dec 2009 Location: Braselton GA Posts: 3 Trader Rating: (0) Feedback Score: 0 reviews	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.