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Broke a valve spring

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Old 10-17-2016, 12:39 PM
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jglassmaker
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Default Broke a valve spring

I was just lightly cruising when the outer spring broke on #4 intake valve. The springs are from a MS4 cam kit from Texas Speed with about 20k miles of daily driving on them with 1 hard track day.

Car runs and has power to do 60+MPH but runs a bit funny and shakes a bit. Since the inner spring is still intact, there is no metal in the oil, and the car doesn't run too bad really - I think my valve is OK. I really don't want to pull the head to check but what do you guys think, just do a compression test and if that is OK consider it fine and install a new spring?


Old 10-17-2016, 12:49 PM
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you know you don't have to pull the head to change it ???? when you change it on the car (engine) you fill the cylinder with air that alone will tell you much !!!
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jglassmaker (10-17-2016)
Old 10-17-2016, 01:22 PM
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Originally Posted by akapounder
you know you don't have to pull the head to change it ???? when you change it on the car (engine) you fill the cylinder with air that alone will tell you much !!!
Yes, I am going to get that spark plug air compressor adaptor thingy tool

I have always taken the heads off before.
Old 10-17-2016, 03:17 PM
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Sucks...but with a cam like that, 20k miles is about as far as I'd take it before I put fresh springs in anyway. MS4's, especially the older ones, are pretty damn brutal on the valvetrain.

It'll take you a couple hours the first time but fill the cylinder with air and get a Comp valve spring compressor to make it a pretty easy job.
Old 10-17-2016, 03:27 PM
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Originally Posted by Cheesecake 07
Sucks...but with a cam like that, 20k miles is about as far as I'd take it before I put fresh springs in anyway. MS4's, especially the older ones, are pretty damn brutal on the valvetrain.

It'll take you a couple hours the first time but fill the cylinder with air and get a Comp valve spring compressor to make it a pretty easy job.
When you say older MS4's do you mean the MS1-3? I thought the Texas Speed "MagicStick" was the cam and MS4 just means version 4 (which is the latest version).

I think I saw Texas Speed post before about how 20k miles on their MS4 was time for new springs if you do most of those hitting high RPMs often like in track conditions. Where if you spend most of it at cruising speeds you could go 40k or even 60k miles. I should call and confirm them later with one of their techs.
Old 10-18-2016, 04:49 PM
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So I called Texas Speed today to get some info on what they see and recommend...
  • 20-25k mile life w/ track time 30-35k mostly cruising
  • Stick w/ springs close to cam, bigger springs might not last longer
  • Just replace valve seals when replacing w/ same springs (no seats/retainers needed)
  • Very rare a break w/ dual springs cause valve damage even with MS4
Old 10-19-2016, 04:54 AM
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The issue is with the springs themselves. Texas Speed had issues with multiple batches of the PRC valve springs. In fact they no longer offer them. Call them up, tell them what happened and send them pics and theyll send you a new set of their new PAC springs for either free or a discount.

Just google "broken prc valve spring"
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Old 10-20-2016, 09:30 AM
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You're lucky you were running the doubles. I had a single PRC Texas Speed beehive break on me and it destroyed the entire motor.

I would go through and replace all the springs in the motor. If one broke, others aren't far behind.
Old 10-21-2016, 01:10 PM
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Fixed the one and everything is good again.
Almost time to put the car away for the winter so will plan to replace the entire set in the spring, hopefully Texas Speed will give me a discount on a new set of PAC springs.

Thanks for all the help

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WildRide357 (10-22-2016)
Old 10-25-2016, 09:02 PM
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MS3-4 are well known spring eaters

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