GTO rocker arm broke

**Jackrabbit** · 09-27-2008, 03:32 PM

Today I installed a mild Patriot cam (580 lift)with Crane 7.4 push rods and PSI LS1511ML springs there specs are :

Outside Diameter Bottom - 1.260"

Inside Diameter Top - 0.630"

Seat Pressure @1.800" (installed height) - 120#

Open Pressure @ 1.175" - 360#

Spring Rate - 384 # per inch

Maximum Lift - .625"

Coil Bind - 1.100"

Valve train is noisey and I broke a stock lifter in half with in the first 5 miles. These springs are supposed to be close to the crane 918 ( I thought ).
Any ideas ?

**bills98ta** · 09-27-2008, 04:42 PM

Are you sure the timing chain was install correctly ? A tooth off can cause the valves to hit the pistons and cause that kind of damage.

**Jackrabbit** · 09-27-2008, 11:29 PM

The cam was installed right on the money. sounded great, in fact it ran like a bat out of hell.

**Jackrabbit** · 10-10-2008, 02:08 PM

problem solved I recieved ls7 springs by mistake. problem coil bind.

**bills98ta** · 10-10-2008, 03:45 PM

Originally Posted by Jackrabbit

problem solved I recieved ls7 springs by mistake. problem coil bind.

Ouch... That will do it. Hope it didn't hurt any lifters. Good Luck !

**Sarge** · 10-12-2008, 04:44 PM

I thought I was the only one that did shit like this. I tried like a bitch to get a timing chain on a pickup one time all damn afternoon....just to find out it was the wrong one....