HyFive578

iTrader: (3)

Already had one motor rebuilt this season due to a failed rocker arm around 200 hours. My 525's now have about 230 hours on them and just to be safe I'm planning on replacing the valve springs and rocker arms this winter. I would prefer to replace the stock Crane rockers and PAC springs with better quality components.

Any recommendations for both?

Cole2534

iTrader: (1)

Call Bob Madera

hammerdown500

Ss rockers heavier but much stronger

Vinny P

Neil,
I agree, call Bob Madera. I am sure he will have a direct replacement valve spring for your 525's. Most likely, it will be Isky. Are you planning on pulling the engines this winter? If not, I doubt you can get the valve springs replaced with the headers on. You may have to reset the installed height to match the new springs. Depends on what the new spring height will be.
As for rocker arms.... I would think that a set of Comp Pro Magnum would do well for you. You may have to change your push rods as well, to get the geometry correct again.
http://www.compcams.com/Products/CC-...kers%27-0.aspx

MILD THUNDER

iTrader: (3)

I dont think the "PAC" is a bad spring, or the Crane Gold is a bad rocker. Seems like the issue with the 525 stock setup, is too little spring pressure. Eddie Young has rebuilt plenty of these, and the stated the spring pressures are quite low. When you do not have enough spring pressure, the valvetrain can no longer control itself. When that happens, $hit breaks. "PAC", is a very good spring, but the best quality spring in the world isnt gonna if it isnt setup properly though.

I learned years back that ISKY springs, are made by PSI. Both good springs, but under the "isky" label, they have much more spring rate selection. Seems like the PSI label, is more suited for high RPM drag stuff.

mike tkach

iTrader: (3)

one might be suprised to know how many pac springs are private labled.on another note,isky does not make a valve spring or hyd roller lifter.where do you think they get them from.??????

HyFive578

iTrader: (3)

Thanks for all of the suggestions. I spoke with Ron Potter this afternoon and he recommended Isky springs and Crower SS rockers. I will contact Bob M. as well and get his opinion too.

MILD THUNDER

iTrader: (3)

Heres the thing. You need to put name brand of the springs aside for a second. What you need to look at, is the installed height. With the installed height being say XXX, you need to select a spring, or possibly different retainers, to get you too xxx installed height, xxx spring pressure, and xxx stack clearance. Its not as simple as just saying I need "isky springs".

Bob M, or Eddie Young, can provide you with the proper spring "SETUP".

As for the Crower stainless rockers, they are a great rocker. A bit more money than their aluminum counterparts, but they will last a long time, aluminum has a fatigue life.

DrugginAnchor

I think only the tool room series are made in house by PSI and sold under the Isky label. Either way, cant be beat.

MILD THUNDER

iTrader: (3)

No doubt the scorpion marine rocker is a nice piece. But you cannot compare the fatigue life of aluminum, to stainless steel. Quote from engine builders magazine

Some of today’s steel rockers are just as light if not slightly lighter than a comparable performance *aluminum rocker. Steel can safely handle a lot of valve spring pressure, up to 950 pounds or higher say the people who make such rockers. Steel has better fatigue strength and stiffness than aluminum, and will stand up to the rigors of racing for a longer period of time – often 2X to 4X as long as comparable *aluminum rockers.