porsche914ls6

iTrader: (1)

I just experienced another broken Scorpion roller rocker. The body of the rocker fractured right where the pushrod seats into the cup. You can now see the pushrod peeking straight through the rocker. This is the second time this has happened in less than 750 miles. I have a theory on why this might be happening and I'd like to ask if anyone else has experienced this problem. I recently bought a pair of Trickflow 215cc heads and I simply bolted down my Scorpion roller rockers that had been on my engine for about 2000 miles. I got a pushrod length checker to see if the Trickflow 7.7 inch rods that came with the heads would work. It appeared that they would work...but I may have missed something somehow. These heads had been on a LS2 motor (block had not been decked). I called Trickflow up and asked if the 7.7 pushrods would work on my uncut LS6 block. I was told the dimensions are identical as far as deck height. I was told by the previous owner of the TFS heads that they had been milled .030. I asked if he had run a slightly shorter pushrod because of the milling and the answer was no. After dinking around with the pushrod length checker (and I've never used one before) I concluded that these pushrods would be ok. TFE even said I should be OK.

Well...my theory is that I need shorter pushrods to relieve the preload that is effecting my current set up. I thought that perhaps the first rocker failure was a bad part. Now a second rocker has failed shortly thereafter and I'm now believing that my pushrods are too long and are causing the rockers more stress than they were designed to take and need to be replaced with a shorter set.

Anyone have this experience or would like to comment on my situation? I'd appreciate any advice or experience you have.

Thanks,

Bill

BadgeZ28

iTrader: (28)

my initial guess is the rocker metal has fatigued and the pushrod length is not the issue. If you observed the position of the rocker tip on the valve stem through a full valve event and it remained close to center, then the length is fine.

99blancoSS

iTrader: (115)

Those scorpions have a terrible reputation for breakage, to the point I would call them garbage.

porsche914ls6

iTrader: (1)

Can you guys recommend a more durable rocker set? I'm thinking about shaft rockers now.

blkbird

iTrader: (28)

Im gonna go with the YT ultralites. Heard nothing but good things about those.

2000WS6ICK

iTrader: (2)

I have the 1.7 scorpion rockers on stock ported 243 heads and stock length chrome moly pushrods. So far no issues with them and I push them to 7000 rpms all the time. I would say you have improper pushrod length. I know scorpion has a lifetime warranty. Give them a call.

Zitty'sZ

iTrader: (29)

I'm running Harland Sharpe 1.7 non adj shaft mounted rockers and I have no complaints with them .

Johnnystock

iTrader: (6)

stock rockers and no complaints after 10 000miles with my setup loll

vettenuts

iTrader: (4)

I would check geometry then re-measure first. Did you check geometry during initial installation (pushrod length has no affect on geometry).

eallanboggs

iTrader: (1)

I installed a set of Scorpion 1.8s on a 5.3 truck about a year ago while doing a bunch of top end mods to the motor. The customer loves them and no call backs. A slightly long pushrod causing rocker failure? I don't think so. Time to go fishing.

heavymetals

iTrader: (3)

Check out the Comp Cams #1500 shaft mount system.

I run that in my V.

Pray

iTrader: (7)

I think your push rods are too long. I had to run 7.6" push rods and every one said they were too long but the geometry and preload is perfect. I also had the scorpions and they broke, twice. Now I run the YT UL's and they are a work of art.

triggerjerk

I have thought about adding Scorpions to my future h/c setup.
Here is what my searching here has yielded:

1. Many think they should not be used on tfs heads.
2. An early batch was defective causing breakages at the pushrod cup/hole area, whatever you call it.
3. Some have broken due to interference with the factory valve covers.

Again, no personal experience, just intraweb hearsay.

bigdsz

iTrader: (1)

Trickflow puts out a quality product but I never realized their heads required a pushrod that was one third of an inch longer. Have you verified that with Trickflow? Seems really odd.

porsche914ls6

iTrader: (1)

I did observe the rocker tip stay close to the center on a full valve event. I'm beginning to believe these Scorpion rockers aren't designed well enough to handle any stress at all. I'm wondering when the next one will break? So far, I've just cleaned up the mess and installed a whole new set (life time warranty)...but then a second one broke all to hell and I'm seriously considering just junking them and replacing them with something better...like a shaft mount system.

vettenuts

iTrader: (4)

One more time, pushrod length does not affect rocker geometry on these rockers. You are fishing in the wrong pond. Did you check geometry when you installed them? If not, check that first before throwing the baby out with the bath water.

porsche914ls6

iTrader: (1)

Are you running a set of TFS heads as well? Were they milled to gain more compression...if so, how much were they decked? Mine are decked .030 and was told from TFS that 7.7" pushrods should be fine. Not quite sure what I'm going to do next. I have a long 3000 mile road trip coming up in two weeks and I'm a bit concerned that even if I drop a set of 7.6" pushrods in...I may find out the hard way that the Scorpions still break. Not sure how they will behave with shorter pushrods? I'll look into the YT UL's. I have heard nothing but good things about them.

Thanks,

Bill

porsche914ls6

iTrader: (1)

How do you suggest I check geometry? Not familiar with how to do this?

Thanks,

Bill

vettenuts

iTrader: (4)

Bill,

See link on how I did my Yella Terra's. Same method, different rocker. Basically you need to ensure the wipe is set correctly. Any adjustments to the rocker height to correct geometry will then affect pushrod length, but first check the geometry.

Link

porsche914ls6

iTrader: (1)

Thanks for the link! I'll check the wipe and see where I need to go from there.