Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum - View Single Post - Broken rocker arm, tossed spring shim. RAS? Cams? Or hard limiter?

KingSpence · 05-31-2014, 02:48 AM

Stock head, so stock springs, retainers, hydraulic lash adjusters. BC 264 IN/EX camshafts. Tomei RAS. Hard limiter set to 7200rpm. 355whp/298tq 14psi.

I'm a noob to this site, but it's a great forum with a plethora of information.

I have an odd powerband, it doesn't peak before redline, it keeps going. This is causing me to be on the upper end of the rpm range, ALL THE TIME.

4500rpm--170hp
5000rpm--260hp
5500rpm--300hp
6000rpm--325hp
7000rpm--355hp

Within 100kms of driving I broke a rocker arm in three pieces. Cylinder #1 exhaust rocker. Tonight as I shifted from first, I hit limiter as my clutch went in, loud backfire, tossed a shim from exhaust rocker #4.

I'm frustrated, and trying to get an idea on what the issue is. I've heard good things, and bad things about RAS, sound like I shouldn't be running them with a stock head. BUT, is this and issue that can be caused by not running stiffer springs in the first place?

I've also heard a hard limiter can be the cause of these issues? What's the advantages, and disadvantages of a hard limiter?

What should I change, what should I keep? I can't have this thing breaking constantly. I spent two hours in a parking lot tonight pulling a camshaft.

Here's a picture of the car we're talking about. Thanks guys!

05-31-2014, 02:48 AM	#1
KingSpence Join Date: Feb 2012 Location: Edmonton, AB Age: 34 Posts: 30 Trader Rating: (0)	Broken rocker arm, tossed spring shim. RAS? Cams? Or hard limiter? Stock head, so stock springs, retainers, hydraulic lash adjusters. BC 264 IN/EX camshafts. Tomei RAS. Hard limiter set to 7200rpm. 355whp/298tq 14psi. I'm a noob to this site, but it's a great forum with a plethora of information. I have an odd powerband, it doesn't peak before redline, it keeps going. This is causing me to be on the upper end of the rpm range, ALL THE TIME. 4500rpm--170hp 5000rpm--260hp 5500rpm--300hp 6000rpm--325hp 7000rpm--355hp Within 100kms of driving I broke a rocker arm in three pieces. Cylinder #1 exhaust rocker. Tonight as I shifted from first, I hit limiter as my clutch went in, loud backfire, tossed a shim from exhaust rocker #4. I'm frustrated, and trying to get an idea on what the issue is. I've heard good things, and bad things about RAS, sound like I shouldn't be running them with a stock head. BUT, is this and issue that can be caused by not running stiffer springs in the first place? I've also heard a hard limiter can be the cause of these issues? What's the advantages, and disadvantages of a hard limiter? What should I change, what should I keep? I can't have this thing breaking constantly. I spent two hours in a parking lot tonight pulling a camshaft. Here's a picture of the car we're talking about. Thanks guys!