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I need a valve spring

947 views 5 replies 4 participants last post by  sunman 
#1 ·
I need a replacement valve spring for a 406 sbc. the inner spring broke after a few hrs of use.
the O.D. is 1.580, I.D. is .750 the free hight is 2.550 its a dual spring w/damper, color code looks white or very light grey, the installed hight looks like 1.900-2.10, hard to measure w/my red neck engineering calipers. it was set up for a soild roller cam .6688 lift using 1.6 rockers
the org. spring manufacture is unknown, I've looked on the net till my eyes R falling out, I dont want to buy a whole set just to replace 1 inner spring.
Please, if U can help, much thanks :thumbup:
 
#2 ·
If I were you, I would take no chances and REPLACE THEM ALL. There are many claiming broken COMP springs - not saying that's what you have, or that's what your problem is. Just saying that for the investment you may very well wind up saving a lot more money in the long run. Have you checked all of your springs pressures???
 
#3 ·
I guess I'll swap out the springs...whats the correct springs for the motor?
263/273 dur @ .50 .627 lift, install hight anywherer from 1.900-2.100
13.8 c/r w/tunnelram, my push rods are 8.100, had 1.6 Lunati rocker on it B4, I have a set of 1.5 CopCams I'm going too,
crane told me the inner spring broke due to using the motor to long in the 2500 rpm range, that this motor is a race only, and the harmonics at low rpms prob. broke the inner spring???
so go to a lower seat pressure and drop my redline to 6K max.
I have a Rev kit, so the solid roller stick and lifters should B ok!
I have a set of teflon oil seals so the inner spring cant B too small.
my inner now measures .753 I.D.

I'm not gonna race the boat, may B wack it every now and then, mostly around 5-6000 max. and 2500-3500 just screw balling around.
 
#4 ·
um... with that setup a 6K redline won't even see your max power potential... If you wanted to keep it under 6K having a more mild build would have netted you MORE power... It really is a nice setup, i just think you're never going to see its full potential.
 
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