This is what I would have thought would be logical, but compressing a spring to any extent for a long period of time has to take some of the tension out of it, I would assume. As you said, better safe than sorry. A $300 set of springs is nothing, relatively speaking.

This should give you a rough idea of the space available. The engine isn't tucked under anything, and there will be easy access to most if not all the springs, but obviously leaning over a fender isn't as handy as working on an engine on a stand.

http://home.earthlink.net/~jimlab/pi...ngine_left.jpg

 

Hell you've got more room than a 4th gen does. IMO you'll have no problems changing them on the car

Edit: I think this is the tool WS6 TA was talking about:

http://www.moroso.com/catalog/catego...?catcode=27035

 

I know. The back half of the engine isn't buried under the firewall, and I'll be able to see and access my spark plugs.

Wonder if that works with Crower shaft rockers. I'm surprised that Crower doesn't offer a tool or at least an adapter of some sort for a standard stud-mount compressing tool.

 

Jim,
The Pacaloy springs should check fine, and will have a much higher resilence to tensile fatigue. Although, their is one major downside of the pacaloy material, instead of getting a little soft before failure they seem to dramatically loose pressure. this is the tradeoff for having a material that lasts longer. My general theory for my driver customers w/ pacaloy's is to replace once a year as preventative maintenance.


On Another note, If you do replace the springs, Make sure you take a good look at the ProPacAlloy springs. We have seen dramatic increases in spring life, even on street driven cars with over 1050Lbs of open pressure.


Thanks
Dennis

 

Dennis, what is the difference between the ProPacallys and the regular Pac's? I run the 943 pacalloys on my motor....

Jason

 

Jason / Jim,
Follow this link for more info.

http://www.compcams.com/information/...SpringCatalog/

Thanks
Dennis

 

Hmm....so what I am getting is that the "pacalloys" we all talk about and run are actually considered the ProPac's then? I dont see any other springs that are called pacalloys....

Thanks Dennis, and by the way....welcome to the board.
Jason

 

Jason, here's a link to Comp Cam's catalog which lists the Pacaloy springs...

http://www.compcams.com/catalog/303.html

I didn't look that hard, but the first mention I found of Pro PAC springs was on this page...

http://www.compcams.com/information/...82_Page-14.jpg

 

Jason,
The Pro-Pac spring is just a "new and improved" longer life alternative to comps proprietary alloy "pacalloy" spring. Some claim as high as 10 times the life of a tradition pacalloy spring.

Thanks
Dennis

 

my humble opinion....if you really want to run the best solid roller spring, buy some PSI springs.

You can only get them through a dealer though

 

Thanks for clearing that up for me Dennis/Jim!
Jason

 

I wasn't impressed. After the guy at Comp gave us the same story (Supposedly going to last us all/most of the season) we put a set on the intake side of an engine.

We had to change 3 springs after 3 passes at the track.

I'm a believer in the Manley NexTeks, another Racer I know has had Fair luck with the PSI stuff also.

 

supposedly by rumor (and somehow it seems true enough to believe) PSI's premium spring is the pacalloy. of course this maybe hard to believe...but this is why I believe it. the last 2 digits of the PSI spring are supposed to be the same as the pacalloy order # from comp....if you check the spring specs you will see this is true...the 2 most popular pacalloys would be the 947 and 948...PSI's part # is 1047 and 1048.....

Some food for thought
Dennis

 

Also worth noting, some cams are just hard on valvesprings. You can take two cams with near identical specification from different manufacturers and one may get twice the spring life. I don't pretend to know exactly why but I'd suspect it's in the lobe design..... closing and opening ramps.

Comp makes a good spring in the Pacs.... but I personally prefer Isky's toolroom springs over any other.

-Mindgame

 

Yepper, I agree with you.

The software plays a big part, as you know, 'Game.

It's not just the ramps, it's everything. Good cam design looks at lift, velocity, acceleration, jerk and the next 3 derivatives (Snap, Crackle and Pop, for want of better names). If those are controlled, the next biggie is getting the profile ACCURATELY ground onto the cam. This involves a nearly perfect master, and a stiff, balanced gam grinding machine. Maybe its no coincidence that some cam manufacturers dedicate one of their best cam grinding machines exclusively to Winston (Nextel?) Cup cams. 9000+ and flat tappets for a million revs is top of the heap in cam design/manufacture in my book.

Any little deviation, which isn't easily measured, can cause bad, not good vibrations...apologies to B. Wilson, one of my favorite composers. This plays havoc with springs. Spintron testing of systems is very useful here.

My $.02