Need help with SBC Vortec Springs.
 

I have a set of L31 Vortec heads running a XM270 Comp Cams roller cam. Lift is 495 and 503. I have run into the situation of having serious questions about the "friend" who assembled my heads. I am concerend that the springs he chose have exessive spring pressure and that I might run into problems down the road. The springs Comp recomends with my cam run 132lbs closed and 280lbs open. Max lift is .560". The springs my "friend" installed are Crane units and spec out at 115lbs closed and 350lbs open. Max lift is .585". The Comp springs needed to have the heads machined for the dia. of the springs while the Crane units are stock diameter. Am I safe with the Crane springs? The heads are getting sent to a reputable shop in a couple of weeks to double check everything.

Randy
"Bad-Habit"

Randy,
Send me the part # for both springs and I will run the rates for you. We can chart the open/closed values on comparative basis for your particular application. I know the cam, just need your installed height.
Bob

The springs I am using now are Crane #99846
http://cranecams.com/index.php?show=...&lvl=3&prt=122

The Comp springs are #986-16
http://www.jegs.com//cgi-bin/ncommer...34&prmenbr=361

BH

Randy,
With a baseline of .500 lift the stats are:
Comp springs
1.750......... 132 lbs
1.250......... 282 lbs
OD 1.430
Rate 296#/in
Crane springs
1.750.........115 lbs
1.250.........319 lbs
OD 1.255
Rate 409#/in
Is the purpose for substituting the Crane springs for the Comps to avoid cutting the spring pockets?
Bob

I belive that WAS the main reason along with the fact he felt comfortable with crane. I have about 70 hours on them. What do those numbers mean to you.....Good,Bad or Ugly.


BH

What does the average spring rate mean? Are you looking for a higher number or lower?

BH

I ran those 99846 springs for 84 hrs in my first motor and they were junk when I took them out.. had a few broken springs along with a few broken dampers.

just my experiance bro

Traviss....Do you feel you got a bad set or that it was the design? I mean I really only have 3 choices that I can tell. Crane,Comp or GM.....Which one would you go with and why? Also what about the Cranes I am using now and the numbers they use? Any thoughts. Is 409 lbs execcissive?

Thanks
BH